PROM - Intermittant PCM Lockup While Reprogramming

File In Section: 06 Engine/Propulsion System

Bulletin No.: 99-08-04-028

Date: September, 1999

INFORMATION

Subject:
Intermittent PCM Lockup When Performing On-Vehicle PCM Reprogramming

Models:
1999 Chevrolet Venture
1999 Oldsmobile Silhouette
1999 Pontiac Montana
with 3.4L Engine (VIN E - RPO LA1)

When performing an on-vehicle PCM reprogramming, a PCM lockup may occur.

The Pass Key(R) III module may intermittently "wake up" during PCM programming and cause interference on the class II data line.

To prevent a lockup from occurring, remove the PASS Key(R) fuse using the following procedure. Refer to the figure.





1. Locate the passenger compartment fuse center (1).

2. Remove the 10 amp PASS Key(R) fuse from the instrument panel fuse center before attempting on vehicle PCM reprogramming (2).

3. After PCM programming is completed, reinstall the 10 amp PASS Key(R) fuse (2).

This will prevent the Pass Key(R) III module from interrupting the class II data line during the programming procedure.

Warranty Information





For vehicles repaired under warranty, use the table.