SW1 L4-1.9L SOHC VIN 8 (1996)
Technical Service Bulletin # 97-T-20A
Date: 971201
EGR System - MIL ON/EGR DTC's Stored.
BULLETIN NO.:97-T-20A
ISSUE DATE: December, 1997
GROUP/SEQ. NO.: Engine-04
CORPORATION NO.: 786506R
SUBJECT:
Malfunction Indicator Lamp (SERVICE ENGINE SOON Telltale Lamp) On and EGR DTCs P0401, P0404, P0405, P1404 and/or P1406 in PCM
Memory (Updated diagnosis and Install Service PCM Calibration)
This bulletin is being revised with updated diagnostic and repair information for the EGR system, bulletin 97-T-2O should be discarded.
MODELS AFFECTED:
1996-1997 Saturns
CONDITION:
The malfunction indicator lamp (MIL) (SERVICE ENGINE SOON telltale lamp) may be On with diagnostic trouble codes (DTCs) P0401, P0404,
P0405, P1404 and/or P1406 stored in PCM malfunction history.
CAUSE:
DTCs P1404 and P1406 may be caused by diagnostic trouble code sensitivity to debris. This debris intermittently prevents the exhaust gas recirculation
(EGR) pintle from fully seating.
The diagnostic information for DTCs P0401, P0404 and P0405 has been updated to include additional failure modes of the EGR system.
IMPORTANT:
The diagnostic logic and operational logic for several DTCs were modified with the calibrations identified in the "Controller/PCM Part Number (End
Model)" table. Referring to the service manual could result in mis-diagnosis and unnecessary replacement of parts.
CORRECTION:
To diagnose these conditions, refer to the diagnostic charts in this bulletin.
PROCEDURE:
Connect the Scan tool or the Service Stall System (SSS) to the vehicle and turn the ignition On.
^
The TECH-2 displays the "Controller Part Number" parameter within the "Vehicle System Information" table.
^
The portable diagnostic tool (PDT) and SSS displays the "PCM Part # " parameter within the "Vehicle ID" table.
