Fault-Tracing Information
Fault-tracing
Preparatory checks
Check and note which adaption area for bank 1 is faulty by going through the list of adaption areas.
The adaptation value is considered outside normal range if it is lower than 0.85 (engine runs rich) or higher than 1.15 (engine runs lean).
Hint: The ranges consist of a table where the first digit in the name designates rpm range and the second load range.
Thus, range 1.1 designates a case with low rpm with low load, and 6.6 a case with high rpm and high load.
Continue - Checking system
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Checking system
- Check the air filter. Check for blockage.
Hint: The fault may be caused by measured air leaking out from the system.
- Check hoses and connections for crankcase ventilation for leakage.
Hint: If the fuel adaptations indicate too rich fuel/air mixture (adaptation value below 1.0) in several adaptation ranges, this indicates a fuel malfunction, e.g., too high fuel pressure.
To find the problem, proceed as follows:
- Check that the engine's oil level is not too high.
Hint: The adaptations may show rich if several cold starts have been performed with short subsequent driving time, e.g., moving of vehicles, and the engine oil has thus been contaminated by gasoline. This affect on the adaptations disappears after a period of driving due to combustion of the fuel vapors by the engine.
- Check the EVAP-valve for leakage.
Hint: A valve that does not seal constantly leaks fuel vapors, which thus affect the adaptations.
- Engine running.
- Check fuel pressure for high fuel pressure.
- Ignition on
- Check residual pressure for too low residual pressure.
Remedy as necessary.
Hint: Normal fuel pressure at idle and warm engine shall be approx. 480 kPa.
The residual pressure when the engine is off and the ignition is on shall be approx. 100 kPa lower than during idle.
If the residual pressure is too low, one malfunction cause may be leaking (non-sealing) injectors, for example.
Continue - Checking mass air flow sensor
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Checking mass air flow sensor
- Engine running.
Check and compare the calculated air mass with the actual air mass readout from the mass air flow sensor.
Try by measuring at different rpms.
Hint: Differences of more than approx. 20% between the signals indicate a malfunction of the mass air flow sensor.
Remedy as necessary.
Note! When replacing mass air flow sensor, repeat the check to verify that the problem has been solved with the replacement.
For more information about current fuel compensation, press 1, otherwise press 2.
1 - Readout of total fuel compensation
2 - Reset adaptations
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Reset adaptations
- Turn off the engine.
- Ignition on
Reset adaptations to zero by pressing on the symbol for VCT2000.
This is done to give the system a normal starting point. Thus it can be seen faster if the adaptations run off up or down.
Continue - Start adaptations
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Readout of total fuel compensation
- Engine running.
- For reading out total fuel compensation at every given moment, press on the symbol for VCT2000.
Hint: The readout value shows the short-term fuel trim's and the long-term fuel trim's total compensation of the injection time in real time.
Positive values indicate additional fuel, negative values indicate reduction of additional fuel.
Try by measuring at different rpms with different engine load.
Note! Keep in mind that the EVAP-valve's addition of fuel vapors affect the readout. For example, squeeze the hose between the EVAP-valve and inlet pipe to minimize addition of fuel from the EVAP-system.
Continue - Reset adaptations
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Start adaptations
Test-drive the vehicle on road and drive variably for 20 minutes, this is to perform as many adaptations as possible.
Check and note if any adaptation range is still incorrect by scrolling through the list with adaptation ranges.
The adaptation value is considered outside normal range if it is lower than 0.85 or higher than 1.15.
Hint: Also, perform a few full throttle accelerations to perform the adaptations that are not affected by normal driving.
For adaptation to start, certain conditions must be fulfilled
- Engine speed ≥ 600 rpm.
- Engine temperature between 80-110°C.
- Adaptation active = executed.
- EVAP-valve not active = 0 micros.
Hint: At high fuel vaporization the EVAP-valve is active longer time and then it may be necessary to disconnect the hose between the EVAP-valve and the canister.
Are these values OK?
Yes - FAULT FOUND
No - Fault-tracing information
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Fault-tracing information
Attempt New Test - Preparatory checks
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