Component Tests and General Diagnostics
Rough Road conditions signal from ABS/EDL Control Module, checking
NOTE:
- If a spinning wheel is detected by the ABS/EDL Control Module the ABS/EDL Control Module produces a Rough Road condition signal. If the Engine Control Module recognises a Rough Road signal, Misfire detection is switched OFF in the ECM.
- The Rough Road condition signal should only be checked if DTC "78074 Rough Road information, engine specified torque, ABS-SG electrical malfunction" is stored in DTC memory.The possible DTC: "Misfire" which may become stored; is a resulting malfunction and can be disregarded.
- The wiring connections and/or the Rough Road condition signal are monitored by the Engine Control Module.
- If an exhaust emissions test is performed on a front wheel drive vehicle with ABS/EDL where the front axle / wheels are rotated while the rear axle / wheels remain stationary, this can cause DTC code "18014" to be stored in DTC memory. Therefore, first remove the ABS/EDL Control Module fuse when performing emissions tests on these vehicles. Check and erase ABS/EDL Control Module and Engine Control Module DTC memories after performing an emissions test.
Special tools, testers, measuring instruments and auxiliary items required
- Scan Tool VAG 1551 with cable VAG 1551/3B
- VAG 1598/22 Test Box
Test conditions
- Control Module coding OK, Refer to "Computers and Control Systems", Engine Control Module, Coding Variants
Test sequence
- Connect VAG 1598/22 Test Box to Engine Control Module harness connector.
- Check signal wire for open or short circuit between Test Box and ABS Control Module using Wiring diagram.
If wiring OK
- Replace ABS Control Module.
If DTC is displayed again after replacing ABS Control Module:
- Replace Engine Control Module.
NOTE: If DTC memory has been erased or the Engine Control Module was disconnected from its Voltage supply, the Readiness Code must be created again , Refer to "Computers and Control Systems", Monitors, Trips, Drive Cycles and Readiness Codes