Cherokee 4WD L6-4.0L VIN S (1998)
Technical Service Bulletin # 18-22-98
Date: 980612
MIL ON, Engine Misfire DTC's Set
NO: 18-22-98
GROUP: Vehicle Performance
DATE: Jun. 12, 1998
SUBJECT:
OBD II Misfire Monitor
THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 18-31-97, WITH EFFECTIVE DATE OF JAN. 30, 1998 WHICH SHOULD
BE REMOVED FROM YOUR FILES AND NOTED IN THE 1997 TECHNICAL SERVICE BULLETIN MANUAL (PUBLICATION NO.
81-699-98004). THE DECARBONIZING PROCEDURE HAS BEEN REVISED ALONG WITH THE LABOR OPERATION TIME ALLOWANCE.
ALL REVISIONS ARE HIGHLIGHTED WITH **ASTERISKS**.
MODELS:
1997 - 1998 (TJ) Wrangler
1996 - 1998 (XJ) Cherokee
1996 - 1998 (ZJ) Grand Cherokee
NOTE:
THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH THE 4.0L ENGINE.
SYMPTOM/CONDITION:
Malfunction Indicator Lamp (MIL) illuminated with either a Multiple Misfire or individual Cylinder (1-6) Misfire Diagnostic Trouble Code (DTC)
recorded in the Powenrain Control Module's (PCM) memory. The MIL illumination may be accompanied by engine vibration.
DIAGNOSIS:
Refer to the 1998 2.5L/4.0L/5.2L/5.9L SF1 Jeep Powertrain Diagnostic Procedures Manual (Publication No. 81-699-97019), test TC-106A for the
Multiple Cylinder Misfire DTC or test TC-107A for the Cylinder # (1-6) Misfire DTC. For any future reference, record and document Freeze Frame
data.
NOTE:
BOTH TEST TC-106A AND TC-107A ARE REVISED WITH TECHNICAL SERVICE BULLETIN 26-12-97 RELEASED DECEMBER 1997.
DO NOT USE THE PROCEDURE LISTED IN THE DIAGNOSTIC PROCEDURE MANUAL UNLESS THE REVISED PAGES HAVE BEEN
INSERTED.
Perform the repair procedure identified in the Powertrain Diagnostic Procedures Manual unless your diagnosis identifies that an engine mechanical
problem could be causing the OBD II Misfire DTC. If the Powertrain Diagnostic Procedures Manual identifies a possible engine mechanical problem,
perform the Repair Procedure.
PARTS REQUIRED:
12
53010388
Springs, Valve
1
04318001
Mopar Combustion Cleaner
POLICY: Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No:
**09-95-20-92
3.1 Hrs.**
FAILURE CODE: XX - Service Adjustment
Repair Procedure
This bulletin involves installing revised valve springs and decarbonizing the combustion chamber.
1.
Use the procedure outlined in the appropriate 1998 Service Manual, Group 9, 4.0L Engine, Removal And Installation, Valve Stem Seal And
Spring, to remove and install the revised valve springs (p/n 53010388).
