Upper Limit
Upper limit
Preparatory checks
Check and note which adaptation range is incorrect. Scroll through the list of adaptation ranges.
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 the engine speed range and the second the loading range. Range 1.1 designates a case with low engine speed and with low loading. Range 6.6 designates a case with high engine speed and with high loading.
Continue - Checking ethanol content
-------------------------------------------------
Checking the mass air flow (MAF) sensor
- Engine running.
Check and compare the calculated air mass with the actual, read-out from mass air flow sensor. Try measuring at different speeds (rpm).
Hint: Differences of more than 20 % between the signals indicate a defective mass air flow sensor.
Remedy as necessary.
Note! When replacing mass air flow sensor. Repeat the check to verify that the replacement solved the problem.
1. For more information about current fuel compensation.
2. Select Continue.
Select one of the above options.
1 - Read-out of total fuel compensation
2 - Resetting adaptation
-------------------------------------------------
Read-out of total fuel compensation
- Engine running.
- For read-out of total fuel compensation at every given moment, press the symbol for VCT2000.
Hint: The read-out value shows the short term fuel trims's and the long term fuel trim's total compensation of injection time in real-time. Positive values indicate addition of fuel. Negative values indicate reduction of fuel.
Try measuring at different speeds (rpm) with different engine loading.
Note! Keep in mind that the EVAP-valve's addition of fuel vapors affects the read-out. Squeeze the hose between the EVAP-valve and inlet pipe to minimize the addition of fuel from the EVAP-system.
Continue - Resetting adaptation
-------------------------------------------------
Resetting adaptation
- Switch off the engine.
- Ignition on.
Reset the adaptations by pressing the VCT2000 symbol.
This is done so that the system can be started from normal. As a result, it is easier to see if the adaptations are going up or down.
Continue - Start adaptations
-------------------------------------------------
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. Scroll through the list of adaptation ranges.
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: Also accelerate at full throttle a number of times to implement the adaptations that are not influenced by normal driving.
For adaptation to start, certain conditions must be fulfilled
- The engine speed is above 600 rpm.
- Engine temperature between 80-110°C.
- Fuel trim active = executed.
- EVAP-valve not active = 0 micros.
Hint: If fuel vaporization is high, the evaporative emission system (EVAP) valve is active for long periods. In this case, it may be necessary to disconnect the hose between the evaporative emission system (EVAP) valve and the EVAP canister.
Are these values OK?
Yes - FAULT FOUND
No - Fault-tracing information
-------------------------------------------------
Fault-tracing information
FAULT-TRACING FAILED - FAULT-TRACING FAILED
Attempt New Test - Preparatory checks
-------------------------------------------------
Checking the system
To investigate what the problem is due to, perform the following:
- Check the intake system for air leakage.
Hint: Incorrectly installed oil dipstick can cause not measured air to be drawn into the engine.
- Check the exhaust system for air leakage.
- Engine running.
- Check for too low fuel pressure.
- Ignition on.
- Check the residual pressure with regards to too low residual pressure.
Remedy as necessary.
- Air leakage exhaust system, check Air Leakage Exhaust System, Check
- Fuel system pressure, checking Fuel System Pressure, Checking
Continue - Checking the mass air flow (MAF) sensor
-------------------------------------------------
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 Testing and Inspection
Continue - Checking the system
-------------------------------------------------