Specifications

up shift).
Customers concerned about this noise should be advised that this condition is normal and no repair
attempts should be made.
A/T - Engine Bucking/Surging at 5,300 RPM
NO: 18-19-98
GROUP: Driveability
DATE: Apr. 10, 1998
SUBJECT: Vehicle Bucking During Wide Open Throttle Acceleration
MODELS:
SYMPTOM/CONDITION:
Some vehicles may experience bucking during wide open throttle (WOT) acceleration. The bucking occurs
at approximately 5300 RPM. This condition may be caused by reaching the high RPM fuel shut off rev
limit before the transmission can shift into the next higher gear and is most likely to occur with high
electrical loads (high beams on, heated back light, heated seats, radio, HVAC blower on MAX etc.). During
high current demands, the generator may emit electrical noise that can affect the transmission governor
pressure sensor output. If this occurs, the transmission may not shift properly to the next higher gear under
(WOT) acceleration conditions and therefore reach the fuel shut off rev limiter. This may be seen most
often between the 2-3 shifts but can also be experienced between the 1-2 shifts.
DIAGNOSIS:
Using 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.
NOTE : ONLY PERFORM THE FOLLOWING PROCEDURE SAFELY ON A HIGHWAY OR ROAD
OBEYING ALL POSTED SPEED LIMITS AND LAWS.
Attempt to duplicate the condition by switching on all accessory loads and driving the vehicle with WOT
accelerations through a shift sequence to see if the engine will reach the fuel shut off rev limiter before the
2-3 or 1-2 shift is made.
If the bucking condition is experienced at approximately 5300 RPM before making the appropriate up
shifts, switch off all electrical loads and repeat the procedure. Repeat the procedure with the electrical loads
on and off a second time. If the bucking occurs with the electrical loads on and does not occur with the
loads off, perform the Repair Procedure.
PARTS REQUIRED:
1996 + (AB) Ram Van
1996 + (AN) Dakota
1996 + (BR/BE) Ram Truck
1998 + (DN) Durango
1996 + (ZJ) Grand Cherokee
1996 + (ZG) Grand Cherokee (International Markets)