Grand Caravan L4-2.4L DOHC (1996)
Technical Service Bulletin # 18-20-98
Date: 980417
A/C Compressor - Bump Feel On Engagement
NO: 18-20-98
GROUP: Vehicle Performance
DATE: Apr. 17, 1998
SUBJECT:
"Bump" Feel During A/C Compressor Engagement
MODELS:
1996 - 1997 (NS) Town & Country/Caravan/Voyager
NOTE:
THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH A THREE-SPEED AUTOMATIC TRANSAXLE AND 2.4L ENGINE.
SYMPTOM/CONDITION:
Some vehicles may exhibit a periodic "bump" sensation in the powertrain when the A/C compressor cycles. It may be described by the vehicle operator
as a slight miss, hesitation or surge while cruising at a steady speed on a smooth road surface.
DIAGNOSIS:
If the vehicle operator is concerned with this "bump" condition, take them and the vehicle for a test drive. Test drive the vehicle with the A/C "ON" at a
steady state speed of 60-65 MPH on a smooth road surface for 3 to 5 miles. If the "bump" is felt, turn the A/C "OFF" and test drive the vehicle at a
steady state speed of 60-65 MPH on a smooth road surface for at least 3 to 5 miles. If the "bump" is not felt with the A/C "OFF," the cause of the bump
is cycling of the A/C compressor clutch.
NOTE:
THE A/C COMPRESSOR CLUTCH ALSO CYCLES DURING DEFROST MODE OPERATION.
Using the Mopar Diagnostic System (MDS) or the Diagnostic Scan Tool (DRB III(R)) with the appropriate Diagnostic Procedures Manual, verify all
engine/transmission systems are functioning as designed. If Diagnostic Trouble Codes (DTC's) are present, record them on the repair order and repair as
necessary before proceeding further with this bulletin. If no DTC's are present and the above symptom has been experienced, perform the Repair
Procedure.
NOTE:
IF A "BUMP" CONTINUES TO BE FELT WITH THE A/C "OFF," FURTHER DIAGNOSIS WILL BE REQUIRED.
PARTS/EQUIPMENT REQUIRED:
1
04861351AA
Motor Mount, Rear
1
05012004AA
Motor Mount, Front
1
CH6000
ScanTool(DRBIII(R))
1
CH7035
General Purpose Interface Bus Cable (GPIB)
1
CH7000/7001
J1962 Cable
1
04669020
Label - Authorized Software Update
1
04275086
Label - Authorized Modification
NOTE:
THE MDS AND DRB III(R) ARE REQUIRED TO PERFORM THIS REPAIR AND THE SYSTEM MUST BE OPERATING WITH RELEASE
21 OR HIGHER AND TIL CD RELEASE 1157 OR HIGHER MUST BE INSTALLED.
POLICY: Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No:
08-19-40-95 Reprogram PCM
0.5 Hrs.
09-40-20-92 Engine Mounts Replace
0.6 Hrs.
FAILURE CODE:
FM - Flash Module
P8 - New Part
