Engine Controls - DTC's 28 and 29 Found

NO: 25-15

DATE: 7-31-2003

MODEL:
2001-2003

M.YEAR:
S/V 40

CHASSIS:
600205-006212

SUBJECT:
DTC ECM 28, 29

REFERENCE:
VADIS, VEMS

THIS TECH NOTE SUPERSEDES THE PREVIOUS TNN DATED 7-7-03. PLEASE UPDATE YOUR FILES.

DESCRIPTION:

The diagnosis of front and rear oxygen sensors can prove difficult since the operation of the rear sensor can influence the operation of the front sensor. The sensors share common sources of potential faults but also have unique fault sources that may trigger DTC ECM 28 or 29.

SERVICE:





If during diagnostics nothing is found the fault may be intermittent. Reset adaptive values (shown) and erase any DTCs. Perform the current VEMS download to ensure the car has the latest version of ECM software.

Resetting Adaptive Values

Instructions for resetting adaptive values are found in the fault tracing instructions for DTC ECM 16 Front Oxygen Sensor.

1. ECM-16. Select signal too high. Permanent fault.

2. Checking the terminal. Were any faults found? Answer yes.

3. Verification. Does the value oscillate between approximately 0 and 1 V? Answer yes.

4. Resetting adaptation. Follow the instructions on the screen.





Warranty Information