RAM 1500 Van V8-5.2L VIN Y (1999)
PROM - Programmable Read Only Memory: All Technical Service Bulletins
PCM - Erroneous Engine Misfire
NUMBER: 18-25-99
GROUP: Vehicle Performance
EFFECTIVE DATE: Nov. 15, 1999
SUBJECT:
Erroneous Engine Miss While Performing Diagnostics With The DRB III
OVERVIEW:
This bulletin involves selectively erasing and reprogramming the JTEC Powertrain Control Module (PCM) with new software (calibration change
99Cal18, 99Cal17, or 99Cal16).
MODELS:
1999
(AB)
Ram Van
1999
(AN)
Dakota
1999
(BR/BE)
Ram Truck
1999
(DN)
Durango
1999
(TJ)
Wrangler
1999
(XJ)
Cherokee
1999
(WJ)
Grand Cherokee
SYMPTOM/CONDITION:
A Powertrain Control Module (PCM) software condition exists that can cause an erroneous engine miss to occur only when in certain screens of the
Diagnostic Scan Tool (DRB III).
The miss will not set a Malfunction Indicator Lamp (MIL), but may be felt and can be seen while performing diagnostics with the DRB III.
This condition occurs only when using the DRB III to read Diagnostic Trouble Codes (DTC's), Secondary Indicators, or 1 Trip Failures and while
driving the vehicle. This is more likely to occur during hard acceleration. While in these screens, a miss may be felt by the technician, or when in the
Secondary Indicators or 1 Trip Failures screen an erroneous injector circuit failure can flash on the DRB III screen with an accompany beep from the
DRB III.
This condition may lead technicians to incorrectly diagnose a problem and may cause erroneous repairs that will not fix the vehicle.
DIAGNOSIS:
Using the Mopar Diagnostic System (MDS2) and or the DRB III with the appropriate Diagnostic Procedures Manual, verify all engine/transmission
systems are functioning as designed. If 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 symptoms have been experienced, perform the Repair Procedure.
NOTE:
WHENEVER A POWERTRAIN CONTROL MODULE (PCM) IS REPLACED DUE TO FAILURE, THE SOFTWARE OF THE
REPLACEMENT CONTROLLER MUST BE VERIFIED FOR THE LATEST REVISION LEVEL. USE THE FLASH PROCEDURE TO
UPDATE REPLACED CONTROLLERS AS NECESSARY.
PARTS REQUIRED:
1
04669020
Label, Authorized Software Update
1
04275086
Label, Authorized Modification
EQUIPMENT REQUIRED:
1
CH6OOO
Scan Tool (DRB III)
1
CH7035
General Purpose Interface Bus Cable (GPIB)
1
CH700017001
J1962 Cable
1
MDS2
NOTE:
THE MDS2 AND DRB III ARE REQUIRED TO PERFORM PART OF THIS REPAIR. WHEN USING THE MDS2 AND THE DRB III
THE SYSTEM MUST BE OPERATING AT CIS CD 2045 OR HIGHER.
REPAIR PROCEDURE: