TCS/ABS - ESP Lamp ON/DTC Stored In ECM
45 ESP light on (DTC "Please read engine control unit")45 10 03
2018191/4
November 29, 2010.
Supersedes Technical Service Bulletin Group 45 number 09 01 dated April 6, 2009 for reasons listed below.
Affected Vehicles
Condition
^ The ESP light is on.
^ DTCS for "Please read memory of engine control unit," or Load/RPM signal missing from engine control unit" or similar are stored in the memory of the ESP control unit.
Technical Background
When ESP regulation is necessary, the system interferes with the engine management system to reduce torque. Before the ESP system activates the brakes, TCS regulation takes place. Therefore the engine management
system must work flawlessly to ensure proper ESP system operation. But if the ESP control unit receives a DTC from the engine control unit, it switches the ESP function off and the ESP lamp comes on. A DTC is also recorded in the ESP control module. The ESP system is not faulty; instead, the deactivation is a predefined step in the ESP control unit.
This condition does not relate to a malfunction of the ESP.
Production Solution
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Service
^ The deactivation of the ESP system is caused by the storage of a DTC in the engine control module. To address this DTC, it is necessary to evaluate the engine management system to ensure proper operation of the ESP system.
Tip: Do not replace the ABS/ESP control module for the above condition. Replacement of the ABS/ESP control module will not solve the above condition and is not authorized.
^ In some cases, no DTC is recorded in the engine management system, but DTC 18265 (Load signal malfunction message from ECM) is stored in the ABS/ESP control module. In order for the TCS or ESP to function properly, the ECM also monitors the load generated from the alternator and A/C compressor to calculate and regulate engine torque. If these signals are missing or corrupt, TCS or ESP control is not possible, and it is important to check these components and wiring.
Warranty
This TSB is informational only and not applicable to any Audi warranty.
Additional Information
All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service manuals for the latest information.