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Speedometer and A/T - Erratic Operation W/Code 24 Set
90oldsmobile12SUBJECT ERRATIC/NO SPEEDOMETER AND ERRATIC TRANS
OPERATION W/CODE 24 REPLACE SPEED SENSOR
MODELS/YEARS 1991 CUTLASS SUPREME, NINETY-EIGHT OR
TORONADO EQUIPPED WITH HYDRA-MATIC 4T60-E (RPO-MI3)
NUMBER: 91-T-26
CORP.REF.NO: 077142
DATE: November 1990
SECTION: 4T60-E
This bulletin covers vehicles equipped with HYDRA-MATIC 4T60-E transaxles which may exhibit erratic or no speedometer reading and erratic transaxle operation accompanied by code 24. These conditions could be caused by an inoperative transaxle speed sensor. When the powertrain control module (PCM) detects an inoperative speed sensor, the PCM will force the transaxle into fail-safe 3rd gear. Fail-safe 3rd gear operation may cause customer comments that the vehicle is sluggish or slips. Oldsmobile models will have detent 2nd gear under heavy throttle positions. Also, an intermittent speed sensor condition may result in normal operation when cold, and when the vehicle is brought up to operating temperature, erratic operation of the speedometer and transaxle.
SERVICE PROCEDURE:
Replace the transaxle speed sensor with the part listed under "SERVICE PARTS INFORMATION".
SERVICE PARTS INFORMATION:
Part Number Description Model Usage
10456034 Speed Sensor Assembly All
Parts are currently available from GMSPO.
SERVICE MANUAL REFERENCE:
Refer to 1991 Service Manual On-Car section for proper disassembly and assembly procedures.