ECU - Low Engine Power at High Altitudes

91chrysler05

NO.: 18-07-91

GROUP: DRIVEABILITY

DATE: June 3, 1991


SUBJECT: Hesitation/Sag 5.9L Engine with Manual Transmission


MODELS:
1989 (AD) RAM PICKUP/RAM CAB & CHASSIS/RAMCHARGER POWER RAM CAB & CHASSIS (4WD)


THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 18-33-90, WHICH SHOULD BE REMOVED FROM YOUR FILES. ALL REVISIONS ARE INDICATED WITH >> ARROWS <<.

>> THIS BULLETIN APPLIES ONLY TO THOSE VEHICLES EQUIPPED WITH THE 5.9L GAS ENGINE AND MANUAL TRANSMISSION. <<


SYMPTOM/CONDITION:

Vehicle may exhibit hesitation/sag during acceleration (throttle tip-in) or when shifting. This condition, including black smoke noticeable from the tailpipe, will be experienced at high altitudes only.


DIAGNOSIS:

Using the 1989 Powertrain Diagnostic Procedures Manual for the 5.9L engine (Publication # 81-699-9012) verify that the vehicle's fuel management system is operating properly. Be sure that the correct diagnostic cartridge is installed in the DRB II tester. If no fault codes are found, perform the following repair procedure.


PARTS REQUIRED:

1 Engine Controller (SMEC) 4638251
1 Authorized Modification Label 4275086

Figure 1:

REPAIR PROCEDURE:

This procedure involves replacing the engine controller (SMEC) with a revised engine controller.

1. Replace existing erigine controller with revised controller as called out in PARTS REQUIRED.

2. Type authorized modification label (4275086) as shown in Figure 1 and attach near VECI label.


*INSERT PART NUMBER USED


POLICY: Reimbursable within the provisions of the warranty.


TIME ALLOWANCE:
Labor Operation No. 08-19-90-94 . . . . . . . . . . . . . . 0.9 Hrs.


FAILURE CODE: NP - Sags, Hesitates and No Power