4.3L - SES Light Illuminated/DTC P1441 - Reprogram (00-06-04-039)

4.3L - SES LIGHT ILLUMINATED/DTC P1441 - REPROGRAM

TECHNICAL SERVICE BULLETIN

SES LIGHT ILLUMINATED, DTC P1441 - (REPROGRAM VCM)

Model(s): 1996 Chevrolet and GMC S/T Models

1996 Oldsmobile Bravada

With Enhanced Evap and 4.3L V6 Engine (VINs W, X - RPOs L35, LF6)

Section: 06 - Engine/Propulsion System

Bulletin No.: 00-06-04-039

Date: September, 2000

CONDITION

Some customers may comment on an illuminated SES light. Further investigation may reveal a DTC P1441. The technician may be unable to determine the root cause of the DTC. This DTC indicates an EVAP system purge during a commanded non-purge event. A Tech II snapshot during this diagnostic, or a "system seal" test commanded through the Tech II, will show NO, or minimal, increase in tank vacuum. This code should not set until a minimum 12" H20 vacuum is seen in the tank for 2 seconds when this diagnostic is running (as indicated by the tank pressure sensor).

CAUSE

A P1441 may set if the VCM detects a change in the fuel control algorithm due to an increase in fuel vapors (rich condition - short-term block learn values decrease) during the time the diagnostic is running. This may occur due to high RVP fuels, or any event, which may cause a temporary rich condition. A calibration change was made for 1998 and newer vehicles to address this concern.

CORRECTION

Follow Strategy-Based diagnostics to determine if the DTC code is intermittent and no root cause can be assigned. Reprogram the VCM calibration with the appropriate calibration from the charts below.

PARTS INFORMATION

For U.S. Applications Use:

Part Number	Description
09374008	L35 & M30 & NF2/NB6-NM8/NN8/Z49 4WD UTIL
09374009	L35 & M50-NM8/NN8/Z49 ALL
09374010	L35 & M30-NM8/NN8/Z49 2WD - ALL / 4WD- PICKUP
09385577	LF6 & M30-Z49 4WD - ALL
09385578	LF6 & M30-Z49 4WD - ALL
09385579	LF6 & M50-Z49 2WD - ALL
09385580	LF6 & M50-Z49 4WD - ALL

For Canadian Applications Use:

The following Canadian AWD application was Not affected by the ABS reflash Special Policy #99046 . Use the listed P/N to install the P1441 "fix". This calibration can be found on TIS 2000 disk 12 shipped to dealers on 6/21/00.

Part Number	Description
09388668	330T & L35 & M30 & NF2/NB6 & Z49

The following calibration P/N's to address the ABS Special Policy #99046 also includes the changes to address the DTC P1441 concern.

Part Number	Description
9360036	S/T & L35 & M50 & NF2/NB6 & Z49
9360032	325S/T 330S & L35 & M30 & NF2/NB6 & Z49
9374020	325S & LF6 & M30 & NF2/NB6 & Z49
9374022	325T & LF6 & M30 & NF2/NB6 & Z49
9374024	325S & LF6 & M50 & NF2/NB6 & Z49
9374026	325T & LF6 & M50 & NF2/NB6 & Z49

The calibrations listed are electronic calibrations and are NOT available from GMSPO. Calibrations were available from Techline starting October, 1999 on the TIS 2000 disk 21 and CD-ROM disk 20/21, except for the AWD Canadian application (P/N 09338668) as noted above.

WARRANTY INFORMATION

For vehicles repaired under warranty, use:

Labor Operation	Description	Labor Time
J6355	Reprogramming VCM, on Vehicle	Use published Labor Time