Vehicle: 2009 Volkswagen Eos Komfort 2.0L
Customer Concern: The battery was disconnected and now the Electro-Mechanical Power Steering Warning light is lit on the dash.
Potential Causes: Unprogrammed Steering Angle Sensor (G85)
Disconnected Battery Steering Limit Stop Basic Setting Procedure:
1. If the battery is disconnected, the basic settings for the Steering Angle Sensor G85 are lost. This will typically result in a trouble code 00778 – G85 Steering Angle Sensor Basic Settings lost in ABS.
2. Unlike earlier models with traditional hydraulic power steering systems, this vehicle is equipped with an electro-mechanical power steering system (large electric motor used to help steering vs. fluid).
3. In vehicles equipped with the electro-mechanical power steering, the G85 basic setting needs to be performed in the Steering Assist control module, not the ABS control module.
a. If the vehicle is equipped with ESP, the G85 basic setting is still set in the ABS control module.
4. Reset the G85 basic setting as follows:
a. Start the vehicle and turn the steering wheel one turn to the right and one turn to the left.
b. Drive a short distance in a straight line on a level surface. Stop with the wheels pointing straight.
c. Leave the engine running and do not move the steering wheel.
d. Select Address Word 44-Steering Assist.
e. Select Function 11-Login or 16-Security Access. Enter a value of 40168.
f. Select Function 04-Basic Settings. Enter Display Group 060. Activate the basic setting. The 1st Display Field should show “OK” when the setting has completed.
g. Select Function 08-Read Measuring Value Blocks (MVB). Enter Display Group 007. The first Display Field should show a value between -1.5° and +1.5°.
5. After the G85 has been successfully set, the Steering Limit Stop adaptation needs to be performed. Loss of Steering Limit Stop Basic Setting will result in trouble code 02546 – Steering Limit Stop No or Incorrect Basic Setting/Adaptation – being stored.
6. Complete the Steering Limit Stop adaptation as follows:
a. With the engine still running, center the steering wheel and hold it for five seconds.
b. Turn the steering wheel completely to the left and hold it there for a second.
c. Turn the steering wheel completely to the right and hold it there for a second.
d. Center the steering wheel.
e. Switch the engine and ignition off.
f. Switch the ignition on and wait five seconds.
g. The Steering Assist Warning Lamp should turn off. If it doesn’t, perform a short test drive.
Tech Tip: If the 02546 fault code does not clear out after the test drive, try repeating the procedure and increase the key cycle times to 30 seconds or more.
Courtesy of Identifix’s "Five Fast Fixes."