Engine Controls - Engine No Crank/No FCM Communication
NUMBER: 08-060-05GROUP: Electrical
DATE: November 16, 2005
SUBJECT:
No Engine Crank - Loss Of Communications With Front Control Module
OVERVIEW:
This bulletin involves the diagnosis, and if necessary the replacement, of the Front Control Module (FCM).
MODELS:
2006 (HB) Durango
2006 (ND) Dakota
2006 (WK) Grand Cherokee
2006 (XK) Commander
NOTE:
This bulletin applies to vehicles built with a Front Control Module having a module julian build date that is prior to "2765" (October 03, 2005). Julian day "275" represents calendar day October 03. Julian year "5" represents calendar year 2005. The build date of the FCM module can be obtained from the module serial number (S/N) that is on the FCM part label. The FCM part number label is located on the outside of the FCM module. Inspect the 6th, 7th and 8th digit in the module S/N to determine the Julian day. Inspect the 9th digit in the S/N to determine the Julian year. A module S/N example is:
T44HUdddy00LKN.
SYMPTOM/CONDITION:
The customer may experience a condition where the engine may not crank, and therefore will not start. Investigation by a technician may reveal that there is a total loss of communications between the scan tool and the vehicle, due to a loss of communications with the Front Control Module (the "gateway" module).
DIAGNOSIS:
1. Was suspect Front Control Module built prior to julian date "2765" (October 03, 2005)?
a. If YES >> Proceed to next step.
b. If NO >> Then this bulletin does not apply.
2. Verify that the vehicle battery is properly charged and that there are no obvious electrical harness disconnects.
3. Will the vehicle engine crank?
a. If YES >> Then this bulletin does not apply.
b. If NO >> Proceed to next step.
4. Connect the StarSCAN(R) to the vehicle Data Link Connector (DLC).
5. Turn the ignition switch to the "Accessory" position (for WK and XK vehicles) or to the "Unlock" position (for HB and ND vehicles).
6. Using StarSCAN(R), attempt electronic communication with the vehicle Front Control Module (FCM). Does the StarSCAN(R) communicate with the FCM?
a. If YES >> Proceed to the next step.
b. If NO >> Perform the Repair Procedure.
7. Turn the ignition switch to the "OFF" position.
8. Is this vehicle a WK (Grand Cherokee) or XK (Commander)?
a. If YES >> Proceed to the next step.
b. If NO >> Then this bulletin does not apply and further diagnosis is required.
9. Disconnect and isolate the negative battery cable from the battery.
10. Leaving the FCM attached to the Integrated Power Module (IPM), remove the IPM from its plastic support bracket (Fig. 1).
11. Disconnect the two 40-way electrical connectors from their electrical cavities on the back of the 1PM housing. Do NOT disconnect the two electrical connectors to the FCM.
NOTE:
During the following steps, be careful not to allow the FCM metal housing to contact the battery positive terminal.
12. Temporarily connect the battery negative cable to the battery.
13. Turn the ignition switch to the "Accessory" position.
14. Locate on the back of the Integrated Power Module the 40-way electrical connector cavity that is identified by a roman numeral "II" (two). The "II" is molded into the IPM housing and easy to see.
15. In the IPM electrical cavity "II" locate pin # 36. Pin # 36 is clearly identified in the "II" cavity. With a DVOM probe pin # 36 for voltage. Is 12 volts present at pin # 36 of 40-way cavity "II" when the ignition switch is in the "Accessory" (on) position?
a. If YES >> Then this bulletin does not apply and further diagnosis is required. Proceed to the next step.
b. If NO >> Turn the ignition switch to the "OFF" position. Perform the Repair Procedure.
16. Turn the ignition switch to the "OFF" position.
17. Disconnect and isolate the battery negative cable to the battery.
18. Connect the two 40-way electrical connectors to the back of the IPM.
19. Install the IPM to its plastic support bracket.
20. Connect the battery negative cable to the battery.
21. Set the vehicle clock to the correct time.
22. Clear the vehicle modules of any DTC's (faults) that may have been caused by the above Diagnosis procedures.
PARTS REQUIRED:
SPECIAL TOOLS / EQUIPMENT REQUIRED:
REPAIR PROCEDURE:
1. Disconnect and isolate the battery negative cable to the battery.
2. Replace the vehicle Front Control Module. Refer to TechCONNECT for the respective service procedures - Service Info Tab / 8 - ELECTRICAL / ELECTRONIC CONTROL MODULES / FRONT CONTROL MODULE / REMOVAL and INSTALLATION.
3. Clear the vehicle modules of any DTC's (faults) that may have been caused by either the Diagnosis and/or Repair Procedures.
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
FAILURE CODE:
Disclaimer:
This bulletin is supplied as technical information only and is not an authorization for repair.