Due to tolerances when manufacturing the injectors the injected fuel quantity may deviate between the actual and calculated fuel quantity. After manufacture these deviations are determined for every injector and a calibration value is determined, the value is converted to a code that is stamped on the injectors. This code is programmed in the engine control unit for each cylinder. Using these codes, the engine control unit corrects the calculated fuel quantity individually for each cylinder and thus improves engine operation and exhaust emissions. With this function, new calibration values can be entered in the engine control unit when replacing injectors or engine control unit.
Note:
If an injector has been overhauled or replaced, the stamped-in adjustment value on the injector must match with that stored in the engine control module for that cylinder.
If the engine control module has been replaced, an adjustment must be performed on all cylinders' injectors to store new adjustment values in the new control module.
The adjustment value is stamped in at the top of all injectors. Below is an example of a seven-digit adjustment value.
Test condition:
Ignition on, engine off.
No faults in the system.
Read off the adjustment value on the injector.
Procedure:
Start the function.
Stored values for all cylinders are shown. If any value should be changed, press "YES".
Select on which cylinder the value should be changed, enter the new value and press "OK" to save.
Values for all cylinders are shown again. Check that the new value for the selected cylinder is saved.
If no other values should be changed, select "NO" to exit the function.
The function is done.
If the function fails, check the test conditions and repair any faults.