Rough Road Sensor: Testing and Inspection

Rough Road Signal From ABS/EDL Control Module, Checking


NOTE:
- When the ABS/EDL control module senses a wheel spinning, it produces the rough road signal. When the ECM recognizes the rough road signal, the misfire recognition is switched off
- Check the rough road signal only when the trouble code 18014 "Rough Road Spec Engine Torque ABS-ECU Electrical Malfunction" is stored. The "Misfire" malfunction is in this case a subsequent malfunction that can be disregarded.
- The wiring and the rough road signal are monitored by the ECM.
- Emissions testing on a front-wheel drive vehicle with ABS/EDL, during which only the front wheels turn while the rear wheels are stationary, can result in the DTC 18014 being stored in DTC memory. Therefore, the fuse for the ABS/EDL control module must be removed. After the test, check DTC memory for the ABS/EDL control module and the ECM. Then erase DTC memory.


Required special tools and test equipment
- VAG 1551 or VAG 1552 Scan Tool (ST) with VAG 1551/3 adapter cable
- VAG 1598/22 test box

Test requirements
- ECM coding OK. Refer to "Programming Control Module (ECM), (Function 07)" Testing and Inspection

Test sequence
- Switch ignition off.
- Connect VAG 1598/22 test box to ECM harness connector. Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAG 1551/1552 Scan Tool" Testing and Inspection
- Check signal wiring for short circuit or open circuit between ECM/test box and ABS control module, according to wiring diagram.

If the wiring is OK:
- Replace ABS control module.

If the malfunction occurs again after the ABS control module has been replaced:
- Replace Motronic ECM -J220-.
- Carry out adaptation of throttle valve control module to ECM.
- Check readiness code. If Diagnostic Trouble Code (DTC) memory has been erased, or ECM was disconnected, generate new readiness.
Refer to "Monitors, Trips and/or Drive Cycle (Readiness Code)/Displaying Readiness Code" Testing and Inspection
Refer to "Monitors, Trips and/or Drive Cycle (Readiness Code)/Generating Readiness Code" Testing and Inspection