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Instruments - Heads-up Display & Cluster Differ

File In Section: 8 Chassis/Body Electrical

Bulletin No.: 10-81-50A

Date: December, 1996

Subject:
Heads-up Display (UV6) And Instrument Cluster Speed Differences (Diagnosis And Repair)

Models:
1992-97 Pontiac Bonneville SSEi and SSE with HUD Option (UV6)

This bulletin is being revised to add the 1996-97 model years and to specify model years for "Canadian Vehicles Only". Please discard Corporate Bulletin Number 10-81-50 (Section 8 - Chassis/Body Electrical).

Condition

Some vehicles may display a condition at 70 mph where the speedometer reads about 4 mph faster or slower than the HUD. This is not an intermittent type condition. Repairs should not be attempted if the speed difference at 70 mph is within 3 mph.

Cause

Variation in the placement of the speedometer pointer can cause this condition.

Correction

If the above condition is confirmed through proper diagnosis, the cluster must be repaired by an authorized Delco repair center.

Diagnosis and repair:

1. Install a Tech I, select the proper engine type, and select vehicle speed.

2. Drive the vehicle and increase speed until the HUD registers 65 mph (use 100 km/h for metric clusters).

a. If the cluster speedometer registers between 62 mph and 68 mph, do not attempt any repairs (95 to 105 km/h for metric units). The accuracy is within allowable limits.

b. If the cluster speedometer registers below 62 mph (95 km/h metric) or above 68 mph (105 km/h metric), verify that the correct HUD module is installed in the vehicle (the part number is on a label either on the top or bottom of the unit). Install a new HUD module if the wrong part was used. If the correct HUD was used, replace the component that shows the greatest speed error when compared to the Tech

Important:
The Tech I speed value may not exactly match either HUD or cluster because of different processing techniques in the PCM.

CANADIAN VEHICLES ONLY

Condition

Owners of some 1992-93 Canadian Pontiac Bonnevilles with the UV6 option (std SSEI/opt SSE) may experience a condition where the Heads Up Display (HUD) registers a speed which is much greater than the speed registered on the instrument cluster (more than 5 km/h at 100 km/h).

Cause

Export HUD's were installed on some Canadian vehicles. Export HUD part number 16156442.

Correction

Install the domestic HUD identified as part number 16134822. Call the local AC Delco Service Center to receive an exchange unit.