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 ethanol content
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Checking system
Hint: If the fuel adaptations indicate too lean fuel/air mixture (adaptation value above 1.0) at idle, this indicates an air leak.
To find the problem, proceed as follows:
- Check the oil dipstick for installation and damage that may cause air leakage, that is, that measured air is not drawn into the engine.
- Check the injectors for incorrect type and any damage that limits injected volume.
- Check the inlet system and exhaust system for leaks.
- Engine running.
- Check fuel pressure to see if it is low.
- 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.
Other information
- Exhaust system, check, B6324S5, B6304T4, B6324S4 Component Tests and General Diagnostics
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 a little in different operating situations for 20 minutes, in order to complete 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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Checking ethanol content
Hint: The cause of the symptom and/or diagnostic trouble code may be that the vehicle has been refuelled with incorrect fuel for that vehicle. The fuel system contains fuel with too high ethanol content.
The energy content in ethanol-diluted fuel is lower than in pure gasoline. This means that the control module compensates for the lower energy content, by increasing the injection volume, to be able to reach lambda=1 at the front heated oxygen sensor. This compensation is normally called "Front lambda control slow" or "Lambda integrator", and varies to compensate for the vehicle's status in the form of component spread, small air leaks, wear, etc. The value of this compensation in the ideal case is 1.0 for pure gasoline. Increased ethanol content of the fuel increases the compensation by approx. 0.05 per 10% ethanol dilution.
The control module is designed to handle an ethanol dilution up to 25%. In combination with other deviations from the ideal case, however, lower ethanol content may be enough to cause customer symptoms. This mainly occurs at engine start with cool engine at outdoor temperatures below 0 °C. Then the diagnostic trouble code may also be set for the engine running on too lean mixture.
Note! In a vehicle intended for gasoline, only pure gasoline shall be used. Even if engine start/operation works, other fuel-related components in the vehicle may be damaged by too high ethanol content.
- Measure the ethanol content of the fuel according to the instructions below.
If measured ethanol content is above 25%, then ethanol dilution is the likely cause of the symptom and/or to the diagnostic trouble code being stored.
If measured ethanol content is below 25%, symptoms and/or diagnostic trouble code may have been caused by earlier occurrence of incorrect fuel in the system for that vehicle.
Hint: Check refuelling history by talking to customer.
If nothing indicates incorrect fuel, neither now nor earlier, continue troubleshooting to check other possible causes of faults.
Other information
- Measuring the ethanol content, B6324S5, B6304T4, B6324S4 Testing and Inspection
Continue - Checking system
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