Regal V6-3100 3.1L VIN M SFI (1996)
PROM - Programmable Read Only Memory: Customer Interest
PCM - MIL ON After Long Deceleration/DTC P0401 Set
File In Section: 6E - Engine Fuel & Emission
Bulletin No.: 87-65-22
Date: August, 1998
Subject:
MIL On After Long Deceleration, DTC PO4O1 Set (EGR Flow) (Reflash PCM)
Models:
1996 Buick Regal
1996 Chevrolet Lumina, Monte Carlo
1996 Oldsmobile Cutlass Supreme
1996 Pontiac Grand Prix
with 3100 V6 Engine (VIN M - RPO L82)
Condition
Some owners may experience a Malfunction Indicator Lamp (MIL) illuminating on the vehicle's instrument panel after a long deceleration with the
transmission typically in the overdrive position. A Diagnostic Trouble Code (DTC) P0401 is stored in the Powertrain Control Module.
Cause
The Exhaust Gas Recirculation Valve (EGR) diagnostic, P0401 EGR Flow, may have failed the self test because the expected change in manifold
pressure (kPa), as displayed by the manifold absolute pressure (MAP) sensor, falls outside the calibrated window.
Correction
A new flash prom calibration is released to correct this condition. Changes are made in the following areas of the diagnostic portion of the calibration:
^
Enabling criteria for the diagnostic to run.
^
EGR control position during the diagnostic.
^
Expected MAP change during the diagnostic.
These changes are being made to prevent false DTC P0401 codes from setting.
Calibration Information
The new calibrations are available from the GM Service Technology Group starting with CD number 15 for 1998.
Important:
Do not attempt to order the calibrations from GMSPO. The calibrations are programmed into the vehicle's PCM via a Techline Tool device.
Calibration
Number
Carline/Axle
Emissions
09365714
All W with
Unleaded
3.33 Axle
Export/Canadian
09365704
All W with
USA Nationwide
3.33 Axle
09365694
Chev W with
USA Nationwide
3.33 Axle
Police Pkg.
Unleaded
09365724
Chev W with
3.33 Axle
Export/Canadian
Police Pkg
Warranty Information
