On-Board Diagnostic (OBD) Function

On Board Diagnostic (OBD) function
The On Board Diagnostic (OBD) function of the ABS/EDL system can detect a total of 14 different malfunctions (23 in the case of vehicles with ASR traction control).

Note:
^ The system performs a self-test routine every time the ignition is switched on. This process is indicated by the yellow ABS warning light -K47- coming on. On vehicles with ASR the traction control indicator light -K86- will also come on. The warning lights will go out after about 2 seconds. The self-test routine continues for a short time when the vehicle is moving, as some malfunctions can only be detected above a certain speed. During the self-test process there will be some audible noise from the relays and the return flow pump in the hydraulic control module, and a slight pulsation at the brake pedal. This is unavoidable, and is not a malfunction which requires repair.
^ If a malfunction is detected by the On Board Diagnostic (OBD) function, the system concerned is switched off automatically for the duration of the current driving cycle. This Is indicated by the relevant warning light in the instrument cluster.

^ The above does not apply to either of the two malfunctions "00526 Brake light switch" and "01203 ABS Dash pan. ins. elect,. connection" DTC table. If one of these malfunctions is detected, none of the warning lights will come on. These malfunctions only affect the operation of the EDL.

WARNING: If VAG 1551 scan tool is connected and the diagnostic link has been established with ABS control module (w/EDL) -JI04-, no control function will be active. This means there is a risk of accident if the vehicle is then driven. The function of the brake system will be impaired because the brake pressure at the rear wheels is no longer controlled by the electronic brake force distribution. This can result in excessive braking at the rear, and the tail of the vehicle may break loose unexpectedly.

Technical data of On Board Diagnostic (OBD)
^ DTC memory
- Permanent memory: contents remain intact when power supply is interrupted.
^ Data output
- Rapid data transfer (operating mode 1)
- The ABS warning light -K47-, the brake system warning symbol and the traction control indicator light -K86- (on vehicles with traction control) will come on in the instrument cluster if a malfunction has been detected and the ABS/EDL and ASR systems are switched off.

^ Functions
01- Check Control Module Versions
02- Check DTC Memory
03- Output Diagnostic Test Mode
05- Erase DTC memory
06- End Output
07- Code Control Module
08- Read Measuring Value Block