V40 L4-1.9L Turbo VIN 29 B4204T3 (2002)
PROM - Programmable Read Only Memory: All Technical Service Bulletins
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.
