RAM 2500 Truck 2WD L6-5.9L DSL Turbo VIN 6 (1998)
Intercooler: Technical Service Bulletins
Engine - Low Power/Poor Performance Diagnosis
NUMBER: 18-21-99
GROUP: Vehicle Performance
DATE: Sep. 3, 1999
SUBJECT:
5.9L - 24V Cummins Diesel Low Power Or Poor Performance Diagnostic
OVERVIEW:
This bulletin involves diagnostic procedure that may be used to assist the technician in the diagnosis of a low power or poor performance complaint.
MODELS:
1998 - 1999 (BR/BE) Ram Truck
SYMPTOM/CONDITION:
The vehicle operator may complain of slow acceleration or a lack of power when towing or hauling moderate to heavy loads. The condition may be
worse at higher altitude.
DIAGNOSIS:
NOTE:
DO NOT PROCEED WITH THIS TECHNICAL SERVICE BULLETIN (TSB) UNTIL TSB 18-11-99 HAS BEEN PERFORMED, ALL
SCHEDULED MAINTENANCE OF THE AIR FILTER AND FUEL FILTER IS CURRENT, AND ANY ACTIVE OR INACTIVE DIAGNOSTIC
TROUBLE CODES (DTC) HAVE BEEN REPAIRED.
Interview the vehicle operator to understand under what driving conditions the above symptom occurs.
1).
While inside the vehicle cab and using the Diagnostic Readout Box (DRB III(R)), verify that the throttle is opening fully.
2).
Refer to the 1999 Ram Truck Service Manual 81-370-9108 pages 14-78 to 14-80. Perform the complete FUEL TRANSFER PUMP PRESSURE
TEST procedure.
3).
Inspect the fuel tank rollover valve for restrictions or that the shipping cap has not been left on the end of the valve.
4).
Inspect the Charge Air Cooler hoses and clamps for proper installation. Inspect all connections and clamps for looseness. Verify that no leaks are
present when the engine is under boost conditions. Pay close attention to the exhaust connections.
5).
While performing the following road test, verify that the turbo boost pressure is 16 psi (33 in. of Hg.) during wide open throttle (WOT)
acceleration. If boost pressure is found to be less than 16 psi (33 in. of Hg.), refer to TSB 11-08-98.
6).
While road testing the vehicle in a safe area and manner, conduct an acceleration test. For vehicles equipped with an automatic transmission
conduct a 0-60 mph acceleration test. For vehicles equipped with a manual transmission, conduct a 40-60 mph acceleration test in 4th gear. It may
take the technician performing several acceleration tests to obtain consistent acceleration times.
