Calibration of the steering angle sensor (G85) on VAG vehicles
Calibration (basic setting) of the steering angle sensor (G85) must be performed after repair work (wheel alignment, steering wheel replacement, clock spring replacement, etc.) or when a DTC code occurs in the fault memory
The steering angle sensor can be calibrated via ECU “16 - Steering column electronics”, “03 - Brake system electronics” or “44 - Power steering”.
ЭThis depends on the vehicle model and the ECU variants installed.
Before calibration
Some ECUs may lose ECU coding at the same time if the sensor calibration is lost.
The unit stores the corresponding DTC codes in the fault memory, for example:
“00778 (0778) - Steering angle sensor (G85)”
“01044 (1044) - The control unit is not coded correctly.”
Also, it is necessary to re-code the control unit if it has been replaced.
In these cases, before starting the calibration of the steering angle sensor, it is necessary to perform coding of the unit using the “Configuration” utility on the “Configuration” tab.
Login or Security Access codes, if required, are transmitted automatically by ScanDoc to the control unit.
If the coding value is correct, simply save it again. If not, select and save a new value based on the factory codes (PR codes) on the vehicle's nameplate.
After successful coding, the corresponding DTC code can be deleted if it has not been deleted automatically.
Calibration
Requirements for performing a basic installation:
- The on-board voltage of the vehicle must be at least 12 V.
- The steering wheel and wheels are aligned straight in the vehicle's axis of motion
- Engine started
Performing the procedure:
Start the vehicle.
Turn the steering wheel all the way to the right/left and then centre the steering wheel.
Drive a short distance on level ground at a speed not exceeding 20 km/h.
Keep the steering wheel straight when driving and stop the vehicle with the wheels aligned straight in the axis of travel.
After stopping, do not turn the steering wheel again.
Leave the engine running and do not switch off the ignition.
Check that the G85 sensor shows acceptable values (±1° to ±5° for different vehicle models).
If the sensor reading is +360° or -360°, remove the steering wheel and turn the clock spring one turn in the direction required for correction (refer to the repair manual).
Run the ‘Steering Angle Sensor Calibration’ utility from the ‘Basic Settings’ tab.
If you have met the requirements and there are no faults in the electrical circuits of the sensor, the adaptation will be carried out almost instantly with a message:
If you see a different message than the one shown above during the calibration process, for example:
it means that the requirements for the procedure are not met or there are other reasons (errors or malfunctions) for the unit to fail to perform the procedure.
Please fix the problems and try calibrating the G85 sensor again.
Once the G85 sensor has been successfully calibrated, you can delete the corresponding DTC code if it has not been deleted automatically.
At the end of the calibration process, you may receive the message "Request rejected by ECU: Access denied, authorization required" or "Request rejected by ECU: Request out of range".
However, the calibration itself will complete successfully.
This is a behavioral feature of some ECUs and is normal.
After calibration
After calibrating the steering angle sensor, DTC codes may appear in the fault memory:
- "01486 (01486) - System Functionality Check Activated"
- "02546 (02546) - Steering Wheel End Position"
This is normal.
Code "01486" means that a test drive must be performed to check the operation of the ABS/ESP sensors.
Code "02546" means that an adaptation of the steering wheel extreme positions must be performed.
Performing a test drive
Requirements for completing a test drive:
- The only fault that should be stored in ECU ‘03 - ABS’ is ‘01486’ and ECU ‘44 - Power Steering’ should have no DTCs in the fault memory.
- The Scandoc must not be connected during the function test.
- The vehicle is stationary.
- The ignition is switched on and the engine is running.
- Perform the trip in an enclosed area (e.g. car park).
- Be sure to perform a function test within 50 seconds of depressing the brake pedal.
Depress the brake pedal firmly until the brake pressure threshold is reached (usually more than 30 bar).
The brake electronics control lamps illuminate to confirm that the test procedure has been started:
- On Bosch ABS models, the ‘ASR/ESP Check Lamp’ (K155) will go out and the ‘ABS Check Lamp’ (K47) will illuminate.
- On Continental/Teves ABS models, the ‘ABS Check Lamp’ (K47) will go out and the ‘ASR/ESP Check Lamp’ (K155) will illuminate.
Start driving in a straight line at a constant speed of ~20 km/h.
Turn the steering wheel left or right from 90° (1/4 turn) to 180° (1/2 turn), leave it in this position and drive at the same speed.
The operation of the ESP sensors is confirmed after the remaining control lamps of the electronic brake system go out.
Error "01486" will be automatically deleted.
At this point, the functional test will be fully completed.
Adaptation of steering wheel end positions
Requirement for adapting the steering wheel end positions:
- The engine's still running.
Centre the steering wheel (±10°) and hold it in the centre position for 5 seconds.
Turn the steering wheel all the way to the left and hold it in this position for 10 seconds.
Turn the steering wheel all the way to the right and hold it in this position for 10 seconds.
Center the steering wheel (±10°).
Switch off the engine and ignition.
Turn on the ignition.
Wait 5 seconds.
The power steering indicator lamp should go out. If this does not happen, carry out a short test drive.
This completes the adaptation of the extreme steering wheel positions.