Computers/Controls - Wrench Lamp ON/Possible DTC U0401
TSB 07-2-202/05/07
WRENCH LIGHT ON-NO DTCS AND/OR U0401
FORD:
2005-2007 Five Hundred, Freestyle
MERCURY:
2005-2007 Montego
ISSUE
Some 2005-2007 Freestyle, Five Hundred and Montego vehicles may exhibit intermittent wrench light on and/or "ETC-failsafe mode" in the message center with no diagnostic trouble codes (DTCs), or a U0401 code in the transmission control module (1CM) of vehicles equipped with a continuously variable transaxle (CVI).
This may be the result of the following: if an intermittent condition that illuminates the wrench light occurs during one drive cycle but does not repeat during the subsequent drive cycle, the powertrain control module (PCM)/TCM software strategy will not store the code in the PCM during the subsequent drive cycle but will instead erase the pending code.
ACTION
Follow the Service Procedure steps to correct the condition.
SERVICE PROCEDURE
1. Pull DTCs from PCM, 1CM modules and instrument cluster (IC).
NOTE
IF ANY CODES, OTHER THAN U0401 ARE IN PCM/TCM/IC MODULES, DO NOT CONTINUE WITH THIS TSB. PERFORM NORMAL DIAGNOSIS PER WORKSHOP MANUAL OR POWERTRAIN CONTROLS/EMISSIONS DIAGNOSIS (PC/ED).
2. Check for main engine harness to PCM (12B637 - Engineering / 12A581 - Service) rub through on the A/C line and on the back right of engine compartment. If rub through is found, repair wires in harness.
3. Pull electronic throttle control (ETC) freeze frame (FF) and follow recommendation below.
Pull ETC FF:
NOTE
VCM (IDS/PDS) MUST BE UPDATED TO SOFTWARE VERSION VCM 2007.1 (IDS/PDS 47.0) OR LATER SOFTWARE LEVEL. FOR 2007.1 (IDS/PDS 47.0), IT IS ALSO REQUIRED TO DOWNLOAD AND INSTALL THE LATEST PATCH.
1. Connect IDS/PDS to vehicle.
2. Open new IDS/PDS session.
3. Select tab.
^ IDS - Toolbox
^ PDS - All Tests and Calibrations
4. IDS Only - Select Powertrain.
5. Select ETC.
6. Follow on screen directions, review results and perform recommended action below.
NOTE
DUE TO THE INTERMITTENT NATURE OF CONCERN, THE MOST LIKELY COMPONENT IS RECOMMENDED FOR SERVICE. WIRING ISSUES, INCLUDING CONNECTOR AND/OR PIN ISSUES MAY ALSO CAUSE CONCERN.
7. On the IDS screen and next to the line IPC DIAGNOSTIC CODE A does a fault exist which is indicated by a one (1) in any location on the line in place of zero (0)?
a. Yes - fault identified, follow recommendation below based on the IDS Repair Direction Results window response. No further analysis is needed.
b. No - go to Step 8.
8. Does IDS screen line ETC FAULT FLAGS indicate a fault (one (1) in any location on line in place of zero (0))?
a. Yes - fault identified, follow recommendation below. No further analysis is needed.
b. No - go to Step 9.
9. Does IDS screen line E-QUIZZER DIAGNOSTIC STATE indicate a fault (one (1) in any location on line in place of zero (0))?
a. Yes - fault identified, follow recommendation below. No further analysis is needed.
b. No-Go to Step 10.
10. Does IDS screen line DESIRED LOAD compared to LOAD indicate a fault (difference is greater then 0.03)?
a. Yes - refer to PC/ED for MAF, ECT, ACT and TP diagnosis.
b. No - go to Step 11.
11. Does IDS screen line MEASURED THROTTLE ANGLE compared to DESIRED THROTTLE ANGLE indicate a fault (difference is greater then 5 degrees)?
a. Yes - replace ETB.
b. No - go to Step 12.
12. If IDS screen line ETC FF is blank (all zeros).
a. Data may be erased by battery or PCM disconnect.
b. If both TCM and ETC FF are blank - replace ETB.
WARRANTY STATUS: Information Only
OPERATION DESCRIPTION TIME
MT070202 Use SLTS Operations If Actual
Available; Claim Additional Time
Diagnosis Or Labor
Performed As Actual Time
Disclaimer