Hydraulic Cooling Fan - Engine Runs Hotter Than Normal
NUMBER: 07-002-01GROUP: Cooling
DATE: Mar. 02, 2001
SUBJECT:
Elevated Engine Temperature Due To Delayed Start Of The Hydraulic Cooling Fan
OVERVIEW:
This bulletin involves selectively erasing and reprogramming the Powertrain Control Module (PCM) with new software (calibration level 01Cal15)
MODELS:
2001 (WJ/WG) Grand Cherokee
NOTE:
THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH A 4.7L ENGINE, WERE BUILT PRIOR TO FEBRUARY 12, 2001 (MDH 0212XX), AND HAVE PCM SOFTWARE THAT IS EARLIER (LESS OR LOWER) THAN 2001 CALIBRATION 15.
SYMPTOM/CONDITION:
A customer may complain that the vehicle engine is operating at higher than normal engine temperatures. The condition may be caused by a delay in the start of the hydraulic cooling fan. The ambient temperature and how the vehicle is used may impact the amount of engine temperature increase.
DIAGNOSIS:
1. Verity the calibration level of the PCM.
2. If the PCM calibration is earlier (less or lower) than calibration 01Cal15 then perform the Repair Procedure.
NOTE:
PERFORM THIS REPAIR FOR ANY VEHICLE THAT IS IN FOR SERVICE.
NOTE:
THE COOLING FAN SHOULD BE OPERATING WHEN ENGINE TEMPERATURE IS BETWEEN 105°C TO 112°C (220°F TO 234°F). IF THE PCM SOFTWARE HAS BEEN REPROGRAMMED TO CALIBRATION 01CAL15 AND THE COOLING FAN FAILS TO OPERATE AT THESE TEMPERATURES, THEN FURTHER COOLING OR ENGINE SYSTEM DIAGNOSIS IS REQUIRED.
PARTS REQUIRED:
EQUIPMENT REQUIRED:
NOTE:
THE MDS2 MUST BE OPERATING AT CIS CD 2078 OR HIGHER.
REPAIR PROCEDURE:
1. Reprogram the PCM using the MDS2 (Mopar Diagnostic System) and the DRB III(R) (Scan Tool).
NOTE:
DUE TO THE PCM REPROGRAMMING PROCEDURE, A DTC MAY BE SET IN OTHER MODULES (EATX, BCM, MIC, SKIM, ETC.) WITHIN THE VEHICLE, IF SO EQUIPPED. SOME DTC'S MAY CAUSE THE MIL TO ILLUMINATE. ALL DTC'S RELATE TO A LOSS OF COMMUNICATIONS WITH A MODULE. CHECK ALL MODULES, RECORD THE FAULTS, AND ERASE THESE FAULTS PRIOR TO RETURNING THE VEHICLE TO THE CUSTOMER. ERASE ANY FAULTS IN THE PCM LAST, AFTER ALL OTHER MODULES HAVE HAD THEIR FAULTS ERASED.
NOTE:
THE FOLLOWING STEPS ARE REQUIRED BY LAW.
2. Type the necessary information on the "Authorized Software Update Label" p/n 04669020 (Fig. 1). Attach the label to the PCM and cover the label with the clear plastic overlay.
3. Type the necessary information on the "Authorized Modification Label" p/n 04275086 and attach the label near the VECI label (Fig. 2).
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
FAILURE CODE: