PROM - Multiple DTC's/No Start/MIL ON

File In Section: 6E - Engine Fuel & Emission

Bulletin No.: 87-65-06A

Date: July, 1998

Subject:
P1621, P1336, P1626, P1631, P1632, MIL, No Start Condition, Theft Deterrent and Crankshaft Position Sensor Related Diagnostic Trouble Codes (Reprogram the PCM)

Models:
1998 Chevrolet and GMC S Models
with 2.2L Engine (VIN 4 - RPO LN2) and 5 Speed Transmission (RPO MW2)





Vehicles Involved:
Involved are certain 1998 S-Truck models equipped with the 2.2L (RPO LN2) VIN Engine Code 4, with RPO MW2 5-Speed manual transmission only. These vehicles tall within the VIN breakpoints as shown.

This bulletin is being revised to correct calibration information. Please discard Corporate Bulletin Number 87-65-06 (Section 6E - Engine Fuel and Emission).

Condition

Some customers may comment on an MIL illumination and possibly a no-start condition with a P1621 and/or a P1336 DTC set, and various DTC's related to the Theft Deterrent System.

Cause

A condition may occur where the PCM is induced to reset the crankshaft position sensor learn and the theft deterrent system.

Correction

If there are no obvious mechanical concerns, reprogram the PCM with the revised calibration that takes into account the above conditions. These calibrations are available on CDROM # 23 and later versions. In addition to this, the Crankshaft Position System Variation Learning Procedure may need to be performed, if P1336 persists. Perform the Crankshaft Position Sensor Variation Learning Procedure using information from the Engine Controls Section of the appropriate Service Manual.

Service Procedure

1. Install a scan tool and verify that one of the previously noted DTC's is set.

2. Note the calibration ID currently in the PCM.

3. Reprogram the PCM with the Calibration Number listed in the table shown.

4. Operate the vehicle and check for any additional DTC's.

5. If the vehicle exhibits a DTC P1336 after the PCM has been reprogrammed, perform the Crankshaft Position System Variation Learning Procedure as noted in the Engine Controls Section of the appropriate Service Manual.

Calibration Numbers





Use the correct calibration from the list.

Warranty Information





For vehicles repaired under warranty, use the table.