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OBD System - Improvement

File In Section: 6E - Engine Fuel & Emission

Bulletin No.: 87-65-18

Date: June, 1998

OBD SOFTWARE UPGRADE

Subject:
On-Board Diagnostic (OBD) System Improvements
(Re-flash Calibration)

Models:
1996-98 Chevrolet Camaro
1996-98 Pontiac Firebird
with 3800 V6 Engine (VIN K - RPO L36) and Manual Transmission (M49) with the Following VIN Breakpoints:

Model Year VIN Breakpoints

1996 SOP - EOP
1997 SOP - EOP
1998 Chevrolet SOP - W2106594
1998 Pontiac SOP - W2205449

While the subject vehicle has been certified as complying with the applicable U.S. Environmental Protection Agency (EPA) and California Air Resources Board (CARB) On-Board Diagnostic (OBD) requirements, we have identified an OBD system improvement that should be implemented whenever practical.

Condition

The vehicle speed sensor circuit code P0500 diagnostic has been disabled.

Cause

The vehicles were released with software which did not enable the vehicle speed sensor circuit diagnostic to detect an open circuit.

Correction





Use a Tech II to verify what software is programmed into the vehicle's Powertrain Control Module (PCM). If the improved software has not been installed, re-program/re-flash with the updated software. Refer to the calibration table for the appropriate calibration change.

Important:
Inform customers that this work is being performed on their vehicles to improve On-Board Diagnostic system operation and does not affect vehicle durability, reliability, or performance.

Calibration Information

The calibrations listed are FLASH calibrations and NOT available from GMSPO. Service FLASH calibrations are available starting with the 1998 # 9 CD ROM.

Warranty Information

For vehicles repaired under warranty, use:

Labor Operation Labor Time

J-6355 Use published labor
operation time

Important:
This labor operation is covered under either the Federal or California Emission Control System Warranty (whichever applies) or the "Bumper-to-Bumper" coverage in the New Vehicle Limited Warranty. The warranty with the broadest coverage applies.