Engine Controls - A/T in Limp Home Mode/MIL ON: Overview
NUMBER: 08-036-05 REV AGROUP: Electrical
DATE: November 12, 2005
THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 08-036-05, DATED JULY 15, 2005, WHICH SHOULD BE REMOVED FROM YOUR FILES. ALL REVISIONS ARE HIGHLIGHTED WITH **ASTERISKS** AND INCLUDE CHANGES TO THE PART SECTION OF THIS BULLETIN.
SUBJECT:
Transmission In Limp-In Mode Or MIL On Due To PCM Ground Wire
OVERVIEW:
This bulletin involves inspecting the C4 (or "D") connector at the Powertrain Control Module (PCM) for presence of moisture, and if necessary, replacing either the two ground wires or the C4 connector.
MODELS:
2005 (KJ) Liberty/Cherokee
NOTE:
This bulletin applies to vehicle equipped with a 3.7L engine and a 42RLE automatic transmission (sales code EKG and DG6 respectively) and built prior to April 18, 2005 (MDH 0418XX).
SYMPTOM/CONDITION:
The customer may notice while driving that the automatic transmission has entered into "Limp-In" mode (2nd gear). The customer may experience a Malfunction Indicator Lamp (MIL) illumination. This condition may be intermittent.
Further diagnostic investigation by the technician may reveal that the MIL is the result of Diagnostic Trouble Codes (DTC's) that are transmission related and may be one of the following:
^ P0714 - Transmission Temperature Sensor Intermittent
^ P0720 - Output Speed Sensor Error
^ P0755 - 2/4 Solenoid Circuit
^ P0760 - OD Solenoid Circuit
^ P0765 - UD Solenoid Circuit
^ P0841 - LR Pressure Switch Sense Circuit
^ P0846 - 2/4 Pressure Switch Sense Circuit
^ P1790 - Fault Immediately After Shift
^ P1794 - Speed Sensor Ground Error
This condition may be due to water entering the PCM ground wires at the ground ring terminal. Water may track internally in the ground wire and deposit moisture inside the C4 connector (green) at the PCM. The source of the water may be a partially unseated plastic push pin used to secure the cowl grill to the cowl panel.
DIAGNOSIS:
1. Using a scan tool (DRBIII(R)) determine if one or more of the above DTC's are present:
2. Turn the ignition switch to the "OFF" position.
3. Disconnect and isolate the negative battery cable from the battery.
4. Remove the C4 connector (green color code) from the Powertrain Control Module (PCM) and inspect the connection for the presence of moisture.
5. If only moisture is present in the C4 connector without evidence of terminal corrosion, then replace only the PCM ground wire in the Repair Procedure.
6. If moisture and evidence of terminal corrosion is present in the C4 connector, then replace the PCM C4 connector in the Repair Procedure.
PARTS REQUIRED:
NOTE:
Harness repair kits are not expected to be available until approximately August 17, 2005.
SPECIAL TOOLS / EQUIPMENT REQUIRED:
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.