Engine Controls/A/C - MIL May Be ON and Various Concerns

Technical Journal

TITLE:
Engine Control Module (ECM) DTC FFFF

CAR MARKET:
United States and Canada

ISSUING DEPARTMENT:
Technical Service

REF NO:
TJ 27341

ISSUE DATE:

YEAR
2013

MONTH
02

DAY
08

PARTNER:
3 US 7510 Volvo Cars North America

FUNC DESC:
Ignition and control system

FUNC GROUP:
2800

"Fixed Right - First Time"

Attachment





Vehicle Type





CSC Customer Symptom Codes





DTC Diagnostic Trouble Codes

Text
Note! If using a printed copy of this Technical Journal, first check for the latest online version.

DESCRIPTION:
Malfunction Indicator Light (MIL) may be lit without any DTC posted or ECM DTC FFFF posted.

A customer may complain about:
- Hard to start.
- Driveability complaints due to wrong information to ECM.
- No temperature indication / wrong temperature indication in Driver Information Module (DIM)
- Maximum AC cooling at cold ambient temperature.

The root cause is a bug in the ECM Software (SW). If the signal from the Temperature-Manifold Absolute Pressure (T-MAP) shows a constant value, approx. +60degC, ECM should post DTC 133C, "Intake air temperature sensor inlet" ("T-MAP").
Instead, DTC FFFF is set or no DTC is set, but the MIL is on. This will lead to improper diagnosis.

PRODUCT MODIFICATION:
ECM SW is corrected from MY 2008. The purpose of the SW is to make sure the ECM sets the correct DTC in the event of the conditions above. The SW is not meant to repair an actual fault in the vehicle.

SERVICE:
DO NOT TRY TO DOWNLOAD ECM UPGRADE AS AN ATTEMPT TO REMEDY THIS DTC.
If FFFF is set in the ECM, fault trace according to VIDA for ECM DTC 133C and remedy as necessary.