Vehicle Will Not Communicate With Scan Tool (GROUP 45, NO. 15-10)

Publication date: 2015-10-05
Reference number: GROUP 45, NO. 15-10
Supersedes refnos: 2042048

VEHICLE WILL NOT COMMUNICATE WITH SCAN TOOL

TECHNICAL SERVICE BULLETIN

Reference Number(s): GROUP 45, NO. 15-10 (2042048/1), Date of Issue: October 5, 2015

AUDI:	A4, A6, A8 1997 - 2001
GROUP:	45 - Anti-lock Brake System (ABS)

45 15 10 2042048/1 October 5, 2015.

APPLICABLE MODELS AND YEARS

Model(s)	Year	VIN Range	Vehicle-Specific Equipment
A4, A6, A8	1997 - 2001	All	Not Applicable

CONDITION

Vehicle will not communicate with diagnostic scan tool or emissions test equipment.
- Customers may have issues with vehicle passing state IM emissions test programs because the scan tool cannot communicate with the vehicle.
- ABS and/or brake lamp(s) will be illuminated in IP cluster.

TECHNICAL BACKGROUND

Broken ground bond wire within the ABS module (ABS 5.3 system) causes diagnostic communication issues with the ABS module, ECM, and TCM.

NOTE: Brake system and ABS system functionality are not affected by the broken ground circuit.

NOTE: This bulletin only addresses the communication issue (broken ground circuit) between the vehicle and the diagnostic scan tool described above. This bulletin does not address any subsequent vehicle diagnostic system issues that may exist:

OBD system works normally; emission or diagnostic critical malfunctions will be indicated by MIL illumination.
ABS system is not functionally affected by the broken ground circuit.

PRODUCTION SOLUTION

Not applicable.

SERVICE

Diagnose Open Ground Circuit:

Disable ABS module in one of the following ways:
- Remove ABS module connector.
- Pull ABS module fuse.
Test for scan tool communication:
- If communication is restored , replace ABS module.
- If communication is not restored , further diagnosis is required following normal GFF protocol.

NOTE: Once this communication issue has been repaired and normal diagnostic communication with the vehicle has been restored, it will be necessary to diagnose further vehicle issues, including possible OBD or ABS issues that may be still indicated by:

MIL lamp illuminated
ABS lamp illuminated
Brake lamp illuminated

If any of these conditions still exist, follow correct diagnostic procedures in GFF.

WARRANTY

This TSB is informational only and not applicable to any Audi warranty.

ADDITIONAL INFORMATION

All parts and service references provided in this TSB (2042048) are subject to change and/or removal. Always check with your Parts Department and service manuals for the latest information.