Mercedes W202 OBD-II Codes (P-codes)
1994-1996

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Here is a list of most of the OBD-II codes and their description. These codes can be pulled from the OBD-II computer with a scantool. Many automotive retail supply stores will do this for you for free.

P0101	Mass or volume air flow circuit range/performance problem (Hot film MAF sensor)
P0105	Manifold absolute pressure implausible
P0111	Intake air temperature circuit range/performance problem (IAT sensor)
P0116	Engine coolant temperature circuit range/performance problem (ECT sensor)
P0125	Insufficient coolant temperature for closed loop fuel control
P0131	O2S 1 (Before TWC) circuit low voltage
P0132	O2S 1 (Before TWC) circuit high voltage
P0133	O2S 1 (Before TWC) circuit slow response
P0134	O2S 1 (Before TWC) circuit no activity detected
P0135	O2S 1 (Before TWC) heater circuit malfunction
P0138	O2S 1 (After TWC) circuit high voltage
P0141	O2S 1 (After TWC) heater circuit malfunction
P0170	Fuel trim malfunction (self adaptation of fuel mixture)
P0200	Injector circuit malfunction
P030x	TWC protection single cyliner misfire (Single cylinder combustion misfire within 200 engine revolutions)
P0300	TWC protection random cylinder misfire
P030x	FTP standards single cylinder misfire (Single cylinder combustion misfire within 1000 engine revolutions)
P0300	FTP standards random cylinder misfire (Random cylinder combustion misfire within 1000 engine revolutions
P030x	I/M test single cylinder misfire (Random cylinder combustion misfire within 1000 engine revolutions)
P0325	Knock sensor 1: control range end stop
P0326	Knock sensor 1: circuit range/performance
P0327	Knock sensor 1: sensor signals
P0335	CKP sensor circuit malfunction
P0341	CMP sensor
P0400	Exhaust gas recirculation flow malfunction
P0411	Secondary air injection incorrect flow detected
P0412	Secondary air injection (AIR) system switching valve/circuit malfunction
P0420	Catalyst system efficiency below threshold
P0441	EVAP without function (logic chain)
P0443	Evaporative emission control system (EVAP) purge control valve circuit malfunction (Purge control valve)
P0500	Vehicle speed implausible
P0501	Vehicle speed signal implausible
P0505	Idle control system malfunction
P0507	Idle control system RPM higher than expected
P0510	CTP information: Air mass implausible
P0600	Serial communications link malfunction (CAN)
P1131	O2S 1 (before TWC) circuit short circuit
P1132	O2S 1 (before TWC) circuit "rich" stop
P1137	O2S (after TWC) circuit short circuit
P1138	O2S (after TWC) operating condition
P1170	Short term fuel trim (self-adaption to fuel mixture)
P1335	Engine speed signal TNA from diagnostic module (OBD II) not received
P1336	CKP sensor signal: Magnet coding on segment
P1337	Engine speed signal TNA not transmitted from engine control module
P1340	CMP sensor monitoring signal from engine control module
P1341	Adjustable camshaft timing solenoid without function (logic chain)
P1342	Electrical activation of adjustable camshaft timing solenoid
P1400	Electrical activation of the EGR switchover valve
P1443	Electrical activation of the purge flow switchover valve
P1444	Pressure switchover without function (logic chain)
P1700	Transmission upshift delay switchover valve withought function (logic chain)
P1701	Electrical activation of upshift delay switchover valve
P1711	Electrical activation of resonance intake manifold switchover valve
P1740	Full load information: Load implausible
P1741	Full load information: Throttle valve position implausible
P1750	Diagnostic module voltage supply from circuit 30 too low

P0101   --   Mass or volume air flow circuit range/performance problem (Hot film MAF sensor)
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip
Test to detect fault:
--The engine control module checks the air mass signal for its limiting value. A fault recognition is transmitted via CAN to the diagnostic module. The diagnostic module recognizes a failure after approximately 2 seconds.

P0105   --   Manifold absolute pressure implausible
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault
Activation of CHECK ENGINE lamp:
--At start of next trip
Test to detect fault:
--The manifold absolute pressure is detected by the diagnostic module pressure sensor and reported to the diagnostic module. If the plausible range (approximately 20 mbar to 1280 mbar) is exceeded for a specified time, a fault is recognized

P0111   --   Intake air temperature circuit range/performance problem (IAT sensor)
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--The engine control module checks the present voltage of the intake air temperature sensor for the limiting values (approximately -90°C to +140°C). If the limiting value is exceeded, a substitute value is created by the engine control module. The fault recognition and the corresponding intake air temperature are tranismitted via CAN to the diagnostic module. The diagnostic module recognizes a failure after approximately 5 seconds.

P0116   --   Engine coolant temperature circuit range/performance problem (ECT sensor)
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--The engine control module checks the engine coolant temperature sensor voltage signal for the limiting values (-42°C to +160°C). If the limiting value is exceeded, a substitute value is created by the engine control module. The fault recognition and the corresponding coolant temperature are transmitted via CAN to the diagnostic module. The diagnostic module recognizes a fault after 2 seconds.

P0125   --   Insufficient coolant temperature for closed loop fuel control
Activation requirement of CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault
--The diagnostic module checks if the operating temperature is reached after a certain time depending on the temperature at start.

P0131   --   O2S 1 (Before TWC) circuit low voltage
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--With the oxygen sensor hot, the frequency of the sensor output signal should be greater than 1.5 Hz. Simultaneously, at a certain load condition and engine speed, mean values are caluclated for the lowest and highest voltage. The difference must be greater than approximately 650mV.

P0132   --   O2S 1 (Before TWC) circuit high voltage
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--With the oxygen sensor control activated, the diagnostic module checks if approximately 1280mV is exceeded for longer than approximately 2.5 seconds.

P0133   --   O2S 1 (Before TWC) circuit slow response
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--Message from engine control module via CAN. Oxygen sensor 2 correction factor exceeded control range.

P0134   --   O2S 1 (Before TWC) circuit no activity detected
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--With simultaneous recognition of "exhaust gas hot" and "oxygen sensor heated," the sensor signal must not remain in one voltage window (below approximately 425mV or above approximately 475mV) for longer than approximately 5 seconds.

P0135   --   O2S 1 (Before TWC) heater circuit malfunction
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with failure.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--Message from engine control module via CAN. Current for oxygen sensor heater is outside the limit (approximately 0.2-2.0 A)) longer than approximately 2 seconds.

P0138   --   O2S 1 (After TWC) circuit high voltage
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with failure.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault
--With the oxygen sensor control activated, the diagnostic module checks if approximately 1280 mV is exceeded for longer than approximately 2.5 seconds.

P0141   --   O2S 1 (After TWC) heater circuit malfunction
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with failure.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--Message from engine control module via CAN. Current for oxygen sensor heater is outside the limit (approximately 0.2-2.0 A) for longer than approximately 2 seconds.

P0170   --   Fuel trim malfunction (self adaptation of fuel mixture)
Activation requirement CHECK ENGINE lamp:
--Immediately at fault recognition.
Activation of CHECK ENGINE lamp:
--Immediately.
Test to detect fault
--The engine control module checks the long-term fuel trim limits for maximum and minimum limits. When the limits are exceeded, a message is transmitted to the diagnostic module via CAN.

P0200   --   Injector circuit malfunction
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with failure.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--The engine control module checks the injector control circuit for short and open circuit. If a failure is detected, a message with identification of the affected injector is sent to the diagnostic module via cAN.
If problems occur for longer than approximately 5 seconds, the diagnostic module recognizes a fault and stores the identification of the respective injector and the freeze frame data.

P0300 to P03XX - (XX is replaced with the cylinder number)
  --   TWC protection single cyliner misfire (Single cylinder combustion misfire within 200 engine revolutions)
Note for testing of ignition misfire:
--The engine control module checks the function of the ignition groups and ignition output stages at engine operating temperature in all load an dengine speed ranges, via the primary voltage pattern. After 4 consecutive faults, the fuel to the affected cylinder is shut off and a message is sent to the diagnostic module via CAN. In addition to this protective measure, to assist in diagnosis, the engine control module counts the number of ignition misfires within 200 engine revolutions.
Note:
--The XX characters shown in the following listings will be replaced with a number, identifying the specific cylinder having the problem.

This number, as well as the affected cylinder is reported to the dianostic module via CAN. This count is continuous, even if the fuel is alrady shut off.

Note for testing combustion malfunction:
--The diagnostic module evaluates the engine speed signal (TNA) for uniformity at each engine revolution. Combustion misfires are recognized by unusal engine torque fluctuations.

P03XX
Random misfire detected (catalytic converter damage protection - ignition misfire/combustion malfucntion on several cylinders within 200 engine revolutions)
Activatoin requirement CHECK ENGINE lamp:
-- Two consecutive trips with fault
Activation of CHECK ENGINE lamp:
--None.
Test to detect fault:
--If several cylinders are involved during the test "Cylinder 1 to 6 misfire/combustion malfunction detected, catalytic converter damage prevention", the fault is recognized and the cylinder numbers and freeze frame data are stored.

P03XX
Random misfire detected (FTP standards - ignition misfire on several cylinders within 1000 engine revolutions)
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--None.
Test to detect fault
--If several cylinders are involved during the test "Cylinders 1 to 12 misfire detected, FTP standards", the fault is recognized and the cylinder numbers and the freezeframe data are stored.

P03XX
Random misfire detected (I/M test - ignitions misfire on sevearl cylinders within 1000 engine revolutions)
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--None.
Test to detect fault:
--If serveral cylinders are involved during the test "Cylinders 1 to 12 misfire detected, I/M program", the fault is recognized and the cylinder numbers and freeze frame data are stored.

P03XX
Cylinders 1 to 6 misfire detected (catalytic converter damage - ignition misfire on one cylinder within 200 engine revolutions)
Activation requirement CHECK ENGINE lamp:
--Immediately at fault recognition.
Activation of CHECK ENGINE lamp:
--None.
Test to detect fault:
--To prevent overheating of the catalytic converter, the diagnostic module checks if the permissible number of ignition misfires has been exceeded. If a fault occurs, the cylinder number and freeze frame data is stored.

P03XX
Cylinders 1 to 6 misfire detected (FTP standards - ignition misfire on one cylinder within 1000 engine revolutions)
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault
Activation of CHECK ENGINE lamp:
--None.
Test to detect fault:
--The diagnostic module sums the number of misfires of 5 successive monitoring periods (within 200 engine revolutions each). If the maximum permissible number for maintaining the emission threshold is exceeded by a factor of 1.5, a fault is recognized. The cylinder number and freeze frame data is stored.

P03XX
Cylinders 1 to 6 misfire detected (I/M test - ignition misfire on one cylinder within 1000 engine revolutions)
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--None.
Test to detect fault:
--The diagnostic module sums the number of misfires of 5 successive monitoring periods (with 200 revolutions each). If the maximum permissible number to maintain the liM program threshold (Inspection and Maintenance program tailpipe emission test) is exceeded, a fault is recognized. The cylinder numbers and freeze frame data are stored.

P0325   --   Knock sensor 1: control range end stop
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault
--The engine control module checks that the knock control system has retarded at least one cylinder to its maximum, or that the retardation of one cylinder differs from the average value of the other cylinders by more than approximately 6° CKA. A message is transmiited to the diagnostic module via CAN if a fault is detected.

P0326   --   Knock sensor 1: circuit range/performance
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault
--If the prepared signals are outside of specified limits, with engine speeds above approximately 3700 RPM and inactive knock sensor system, the engine control module recognizes a fault and transmits a message to the diagnostic module via CAN.

P0327   --   Knock sensor 1: sensor signals
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--The engine control module recognizes sensor signals as implausible if they do not exceed a specified signal level threshold. The test is performed at high engine speeds with the knock sensor system activated. If a fault is detected, ignition to all cylinders is retarded and a message is sent to the diagnostic module via CAN.

P0335   --   CKP sensor circuit malfunction
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--The engine control module checks the AC voltage signal created by the crankshaft segment front and rear edges and their correct sequence. Failures are transmiited to the diagnostic module via CAN. The diagnostic module recognizes a fault after approximately 5 seconds, if the air mass is above idle speed value.

P0341   --   CMP sensor
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault
--The engine control module checks if the number of TNA pulses (crankshaft segments) between two camshaft pulses equals the number of cylinders. The number of crankshaft segment rear edges in one camshaft revolution must equal the number of cylinders. If irregularities are detected, a message is sent to the diagnostic module via CAN. A fault is recognized after approximately 2 seconds.

P0400   --   Exhaust gas recirculation flow malfunction
>Activation requirement CHECK ENGINE lamp:
--After one "performed" test with failure.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--The EGR logic chain is checed if the following conditions are simultaneously satisfied:
• No failure in the electrical activation of the EGR switchover valve
• Deceleration fuel shut-off operating
• Closed throttle position recognized
• Engine speed approximately 1900-2600 RPM and constant
• Intake manifold pressure less than 325 mbar
• Momentary intake air temperature >10°C
After approximately 1 second, the diagnostic module determines the intake manifold pressure. Initiated by the diagnostic module (via the CAN data bus), the engine control module then briefly activates the EGR switchover valve. The intake manifold pressure is evaluated for approximately 3 seconds.

The pressure in the intake manifold must drop by at least approximately 15 mbar while the EGR switchover valve is activated.

P0411   --   Secondary air injection incorrect flow detected
Activation requirement CHECK ENGINE lamp:
--After two consecutive tests with failure.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault
--The secondary air injection logic chain is checked if the following conditions are simultaneously satisfied:

• No failure in the electrical activation of the secondary air injection pump
• Closed throttle position recognized
• Engine speed below approximately 850 rpm
• Vehicle speed 0 mph
• Load condition below approximately 60%
• Barometric pressure above 780mbar
• Oxygen sensor control activated
• Secondary air injection pump activated at least once after engine start.

If all conditions are met, the diagnostic module requests "secondary air injection" from the engine control module (via CAN data data bus). The diagnostic module then checks the signal of the oxygen sensor 1 for approximately 6 seconds - it must be continuously in the lean mixture range.

P0412   --   Secondary air injection (AIR) system switching valve/circuit malfunction
Activation requirement CHECK ENGINE lamp:
--After two consecutive tests with failure.
Activation of CHECK ENGINE lamp:
--At start of next trip
Test to detect fault
--The engine control module checks if the secondary air injection system is controllable, and sends a message via CAN if a fault is detected. The diagnostic module recognizes a fault if problems are present for longer than approximately 5 seconds.

P0420   --   Catalyst system efficiency below threshold
Activation requirement CHECK ENGINE lamp:
--After two consecutively "performed" tests with fault.
Activation of CHECK ENGINE lamp:
--None.
Test to detect fault:
--Oxygen sensor 2 (after catalytic converter) is required for this test. To begin the test, the following conditions must be met simultaneously:
• Oxygen sensor control approved
• Load approximately 25-45%
• Vehicle speed approximately 47-50 MPH (75-80 KMH)
• Vehicle speed constant
• Engine coolant temperature above approximately 76°C for at least 10 minutes
• Oxygen sensor signals at least 16 oscillation shifts and frequency greater than 1.5 Hz
• Minimum signal range of oxygen sensor 2 (after catalytic converter) exceeded (approximately 200mV)
• "Catalytic converter hot" message from engine control module via CAN
The diagnostic module compares the oscillations of both oxygen sensor signals for phase shift (time delay). THe oscillation from "rich" to "lean" or vice versa has a time delay between the oxygen sensor 2 (after catalytic converter) and the oxygen sensor 1 (before catalytic converter). If a specified value is exceeded (approximately 160° Phase shift), the catalytic converter has reached its aging limit.

P0441   --   EVAP without function (logic chain)
Activation requirement CHECK ENGINE lamp:
--After two consecutively "performed" tests with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip
Test to detect fault
--The logic chain of the evaporative emission control system is checked if the following conditions are met simultaneously
• No failure of electrical activation for purge switchover valve
• Activation of purge switchover valve with an on-off ratio between approximately 40-60%
• Engine speed and load range between 2000-3000 RPM and between 25 and 50% load.

P0443   --   Evaporative emission control system (EVAP) purge control valve circuit malfunction (Purge control valve)
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault
Activation of CHECK ENGINE lamp:
--At start of next trip
Test to detect fault
--The engine control module checks the Y58/1 control circuit for short circuit and open circuit. If a fault is detected, a message is sent to the diagnostic module via CAN. The diagnostic module recognizes a fault if problems occur for longer than approximately 2 seconds.
--If all conditions are met, the diagnostic module activates the purge flow switchover valve. The diagnostic module pressure sensor thereby detects the pressure in the line from the charcoal canister to the purge control valve. The pressure pattern in the line varies correspondingly to the cycled activation of the purge control valve.
--The diagnostic module monitors the pressure pattern for approximately 4 seconds. If the pressure values vary by less than approximately 50mbar, a fault is recognized. At higher elevations, a barometric (altitude) correction takes place (e.g. above 2400 meter pressure variations of approximately 11mbar are permissible).

P0500   --   Vehicle speed implausible
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with failure
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault
--The engine control module checks the vehicle speed signal. With an implausible vehicle speed signal, a message and the recorded speed is sent to the diagnostic module via CAN.

P0501   --   Vehicle speed signal implausible
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with failure.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault
--The vehicle speed signal transmitted via CAN must be less than 158 mph (255 km/h), otherwise the diagnostic module recognizes a fault.

P0505   --   Idle control system malfunction
Activation requirement CEHCK ENGINE lamp:
--Two consecutive trips with failure.
Activation of CHECK ENGINE lamp:
--At start of next trip
Test to detect fault:
--The diagnostic module receives the fixed operating (limp-home) mode message of the idle speed control via CAN. If this message remains after approximately 5 seconds, the diagnostic module recognizes a fault.

P0507   --   Idle control system RPM higher than expected
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with failure.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--With vehicle stationary, A/C compressor turned off and engine at operating temperature, the idle speed control checks if the regulating value at the idle speed control actuator has reached its lower limit and if the engine speed is still too high. This is transmitted via CAN to the diagnostic module.
--If the regulating value remains at the lower limit for a specified time and the engine speed deviation is greater than approximately 150 RPM, the diagnostic module recognizes a fault.

P0510   --   CTP information: Air mass implausible
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with failure.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault
--The engine control module checks if the air mass is less than a specified threshold at recognized idle speed. A message is sent to the diagnostic module via CAN if a fault occurs.

P0600   --   Serial communications link malfunction (CAN)
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault
Activation of CHECK ENGINE lamp:
--At start of next trip
Test to detect fault
--The CAN data bus between all control modules is monitored via the CAN controller circuit in the diagnostic module.

P1131   --   O2S 1 (before TWC) circuit short circuit
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--During deceleration fuel shut-off, the sensor signal must react and be out of the rich mixture range within approximately 2 seconds.

P1132   --   O2S 1 (before TWC) circuit "rich" stop
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault
Activatoin of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault
--With oxygen sensor control approved, "oxygen sensor heated" and "exhaust gas hot", the diagnostic module checks if the oxygen sensor integrator remain on the "rich mixture" limit for longer than approximately 5 seconds.

P1137   --   O2S (after TWC) circuit short circuit
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault
--During decleration fuel shut-off, the sensor signal must react and be out of the rich mixture range within approximately 2 seconds.

P1138   --   O2S (after TWC) operating condition
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--With the "TWC Hot", the diagnostic module checks if the sensor voltage is greater than approximately 200mV within approximately 5 minutes.

P1170   --   Short term fuel trim (self-adaption to fuel mixture)
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--The engine control module checks the short term fuel trim for maximum and minimum limits. When the limits are exceeded, a message is transmitted to the diagnostic module via CAN.

P1335   --   Engine speed signal TNA from diagnostic module (OBD II) not received
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault
--The diagnostic module checks whether amplitude changes (AC voltage) of the TNA-signal occur at engine speeds above 500 RPM.

P1336   --   CKP sensor signal: Magnet coding on segment
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp
--At start of next trip.
Test to detect fault:
--The engine control module checks the position of the magnet inserted into one of the crankshaft segments. Faults are reported to the diagnostic module via CAN.

P1337   --   Engine speed signal TNA not transmitted from engine control module
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--The engine control module transmits the engine speed signal TNA to the diagnostic module. Thereby, the engine control module's output is checked for electrical function and a message is sent via CAN if a fault occurs. The diagnostic module recognizes a fault if problems occur for longer than approximately 2 seconds.

P1340   --   CMP sensor monitoring signal from engine control module
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--The diagnostic module checks if the number of TNA pulses (= crankshaft segments) between two camshaft pulses equals the number of cylinders. The number of crankshaft segment rear edges in one camshaft revolution must equal the number of cylinders.

P1341   --   Adjustable camshaft timing solenoid without function (logic chain)
Activation requirement CHECK ENGINE lamp:
--After one "performed test" test with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip
Test to detect fault:
--The logic chain of camshaft timing adjuster is checked if the following conditions are met simultaneously:
• No failure of electrical activation of camshaft timing adjuster solenoid
• Decleration fuel shut-off active
• Idle speed contact closed
• Engine speed between approximately 1600-2500 RPM and constant
• Intake manifold vacuum less than approximately 250mbar
• Altitude below approximately 2000 meters
• Momentary intake air temperature >10°C.
--The diagnostic module determines the momentary intake manifold vacuum after approximately 1 second. Initiated by the diagnostic module (via the CAN data bus), the engine control module then acutates the camshaft timing adjuster solenoid for approximately 2 seconds. At the same time, the intake manifold vacuum is further evaluated for approximately 6 seconds.
--A fault is recognized if the intake manifold vacuum does not change by at least approximately 15mbar, when the camshaft is adjusted from "advanced" to "retard" or vice versa (camshaft timing adjuster solenoid activated Camshaft position "advanced" = intake manifold vacuum higher).

P1342   --   Electrical activation of adjustable camshaft timing solenoid
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with failure.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--The engine control module checks the electrical actuation of Y49 and sends a message via CAN. The diagnostic module recognizes a fault if problems occur for longer than approximately 2 seconds.

P1400   --   Electrical activation of the EGR switchover valve
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with failure.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--The engine control module checks the activation of Y27 and sends a message via CAN if a fault is present. If a problem occurs longer than approximately 5 seconds, the diagnostic module recognizes a fault.

P1443   --   Electrical activation of the purge flow switchover valve
Activation requirement CHECK ENGINE lamp:
--After two consecutively "performed" tests with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--The diagnostic module checks the Y27/6 control circuit for short circuit and open circuit. The diagnostic module recognizes a fault if problems occur for longer than approximately 2 seconds.

P1444   --   Pressure switchover without function (logic chain)
Activation requirement CHECK ENGINE lamp:
--After two consecutively "performed" tests with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault
--To actuate the logic chain, the following conditions must be met simultaneously:
• Purge control valve closed
• No deceleration fuel shut-off
• Momentary intake air temperature > +10°C
• Evaporation ratio not in 40-60% range.
--The diagnostic module subsequently activates the purge flow switchover valve. The diagnostic module pressure sensor thereby detects the barometric pressure via the charcoal canister.
--This barometric pressure is compared with the intake manifold pressure values which are measured during decleration. The barometric pressure must be higher by more than approximately 250mbar, otherwise a fault is present is the switchover function.

P1700   --   Transmission upshift delay switchover valve withought function (logic chain)
Activation requirement CHECK ENGINE lamp:
--After two consecutive "performed" tests with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault
--The test is performed, if the following conditions are met simultaneously:
• No failure in electrical activation of upshift delay switchover valve.
• Transmission upshift delay active
• Load below approximately 55%
• Engine not at idle speed
• Transmission selector not in Park/Neutral Position.
The diagnostic module checks the engine RPM at a certain vehicle speed. If a predetermined engine speed threshold is not exceeded, a fault is recognized.

Model	KM/H (MPH)	RPM
202.022 (C220)	47-15 (29-32)	1750
202.028 (C280)	42-45 (26-28)	2100

P1701   --   Electrical activation of upshift delay switchover valve
Activation requirement CHECK ENGINE lamp:
--After two consecutive "performed" tests with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--The engine control odule checks the Y3/3 control circuit for short circuit and open circuit. If a fault is detected, a message is sent to the diagnostic module via CAN. The diagnostic module recgonizes a fault if problems occur for longer than approximately 5 seconds.

P1711   --   Electrical activation of resonance intake manifold switchover valve
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault
--The engine control module checks if Y22/6 can be controlled and transmits a message via CAN if a fault is present. The diagnostic module recognizes a fault if problems occur for longer than 2 seconds.

P1740   --   Full load information: Load implausible
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp
--At start of next trip.
Test to detect fault:
--The engine control module checks (except during ASR operation) if the load condition exceedes a specified threshold when full load is recognized. A message is sent to the diagnostic module via CAN is the comibination is improper.

P1741   --   Full load information: Throttle valve position implausible
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault
--The engine control module checks (except during ASR operation) if the throttle valve is correspondingly opened at full load recognition. A message is sent to the diagnostic module via CAN if the combination is improper.

P1750   --   Diagnostic module voltage supply from circuit 30 too low
Activation requirement CHECK ENGINE lamp:
--Two consecutive trips with fault.
Activation of CHECK ENGINE lamp:
--At start of next trip.
Test to detect fault:
--For circuit 30:
With voltage below approximately 8V (up to 2000 RPM) or below approximately 10V (2000-6000 RPM), the engine control module no longer performs any tests. As a result, low voltage conditions which are present for more than approximately 5 seconds are stored as a fault by the diagnostic module.
--For circuit 87:
Recognized by the engine control module as implausible.

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