On-board diagnosis function - GF07.12-P-3009H

ENGINE 606.912 in MODEL 210.020 to 31.5.96 with CODE (491) U.S. version 

On-Board Diagnosis II (OBD II) functions are stored in the IFI [ERE] control module (N3/7).

Task 

To detect faults in the injection system and store them in memory. Ambient conditions prevailing at the time of the fault are also stored.

Function 

Fault path testing 

Under certain operation conditions, fault paths are checked for problems such as short or open circuits, implausible signals and illogical combinations.

Notes on DTC memory 

• DTC memory: fault display

  current faults  : are displayed against a gray  field

  stored faults  : are shown against a light  background

All inputs and outputs are checked for plausibility during operation.

All faults that occur are stored in the DTC memory of the IFI [ERE] control module (N3/7).

The faults remain stored when the ignition is "OFF" and after disconnecting the vehicle battery.

Emissions-related faults trigger the

CHECK ENGINE

malfunction indicator lamp (A1e26) and the

CHECK ENGINE

ENGINE ELECTRONICS

indicator in the multifunction display.

The faults are marked by an OBD trouble code.

Such faults include:

• Lifting sender B28/3
• EGR [ARF] vacuum transducer Y31/1

  Pressure control flap vacuum transducer Y31/2

Fault ambient data 

The fault ambient data at the time the fault was stored can also be displayed using the HHT. Only the ambient data which existed when the fault occurred for the first time is stored. The ambient data is spread over several display screens (up to 8 display screens). The last two display screens are reserved exclusively for development.

Display screens showing the result √/F point to the fault causes, such as:

• Voltage too high
• Voltage too low
• Signal too strong
• Signal too weak
• Value implausible

Definition: Test readiness 

Relevant fault path tests and causal chains must be gone through completely at least once from ignition ON to ignition OFF (one operating cycle). Therefore two "completed" tests can only be achieved over two operating cycles.

Operating cycle 

One operating cycle has been completed when

• Coolant temperature > 60°C
• Engine speed at 2500 rpm for 5 s
• Ignition 5 s OFF
• Engine speed at 2500 rpm for 5 s
• Ignition 5 s OFF
• Engine speed at 2500 rpm for 5 s

  See HHT menu 3/8 - OBD II test readiness

	IFI [ERE] control module location/task/function		GF07.12-P-3102H
	CHECK ENGINE malfunction indicator lamp location/task/function		GF07.13-P-3144H
	Diagnostic trouble code description		dh0301p100013x