Cutlass Ciera Cruiser V6-3300 3.3L (1989)
Speedometer Head: Technical Service Bulletins
Engine Controls - Updated Speed Sensor Diagnosis
SUBJECT:
SERVICE MANUAL UPDATE - SECTION 8A, VEHICLE SPEED SENSOR DIAGNOSIS
MODELS/YEARS:
1989 CUTLASS CIERA
NUMBER:
89-T-86
CORP. REF. NO: 938122
DATE:
JULY 1989
SECTION:
8A
Add the following symptom to the Symptom Tables for the 1989 Cutlass Ciera Service Manual, Section 8A, pages 33-3, 33-4, 33-5 and 33-7 for the
Vehicle Speed Sensor Diagnosis.
Speedometer is
Do Test G
inaccurate
On pages 33-4 and 33-7 insert the following test.
G: SPEEDOMETER IS INACCURATE
1.
Connect a scan tool to the ALDL connector. Drive the vehicle, observe the Speedometer and compare it to the vehicle speed shown on the scan
tool.
*
If both the speedometer and scan tool display the same speed, check for correct tire size, VSS drive gears and ECM PROM.
*
If scan tool and speedometer do not display the same speed, replace Instrument
Cluster.