INFORMATION ON PCM CALIBRATION ENHANCEMENT. Cadillac Concours 1997

REVISION: 09/05/97

THIS BULLETIN IS REVISED TO INCLUDE THE 1997 MODEL YEAR COMMERCIAL CHASSIS CALIBRATION. PLEASE DISCARD CORPORATE BULLETIN 77-65-07 (SECTION 6E - ENGINE FUEL & EMISSION). ______________________________________________________________________

SUBJECT: INFORMATION ON PCM CALIBRATION ENHANCEMENT

MODELS: 1997 CADILLAC CONCOURS, DEVILLE, ELDORADO, SEVILLE 1997 OLDSMOBILE AURORA WITH 4.0L, 4.6L ENGINES (VINS C, Y, 9 - RPOS L47, LD8, L37)

A PCM CALIBRATION ENHANCEMENT HAS BEEN RELEASED FOR THE 4.0L AND 4.6L ENGINES IDENTIFIED ABOVE AND BUILT BEFORE FEBRUARY 1, 1997. THIS PCM CALIBRATION CAN BE USED TO SERVICE 1997 MODEL YEAR 4.0L AND 4.6L ENGINES WITH THE FOLLOWING DTCS AFTER FOLLOWING THE COMPLETE INSTRUCTIONS FOR EACH DTC CODE LISTED BELOW.

DTC DTC DESCRIPTION -------- ---------------- P0135, P0141, P0147, P0155 O2 HEATER CODE P0133, P0153 O2 RESPONSE SLOW TIME P1134, P1154 O2 RATIO OF RESPONSE TIMES P1140 O2 RESPONSE RATIO PRE-CONVERTER O2 P0325 KNOCK SENSOR MODULE CIRCUIT P0401 EGR SYSTEM MALFUNCTION SURGE LIGHT-LOAD SURGE AT 30-35 MPH

IF ANY OF THE DTCS ABOVE ARE PRESENT, CAREFULLY FOLLOW THE STEPS LISTED BELOW:

PROCEDURE:

1. BUILT BEFORE FEBRUARY 1997 IF THE VEHICLE WAS PRODUCED PRIOR TO FEBRUARY 1, 1997, PROCEED TO STEP 2 BELOW. IF THE VEHICLE WAS PRODUCED AFTER FEBRUARY 1, 1997, CONSULT THE DIAGNOSTIC PROCEDURES FOR THE SPECIFIC DTCS LISTED IN SECTION 6E OF THE APPLICABLE SERVICE MANUAL.

2. PREVIOUS UPDATE WITH TECHLINE CD ROM DISC #1 1997 IF THE VEHICLE WAS UPDATED WITH AN ENHANCED CALIBRATION FROM TECHLINE CD ROM DISC #1 1997, CONSULT THE DIAGNOSTIC PROCEDURES FOR THE SPECIFIC DTCS LISTED IN SECTION 6E OF THE APPLICABLE SERVICE MANUAL. IF THE VEHICLE WAS **NOT** UPDATED WITH AN ENHANCED CALIBRATION FROM TECHLINE CD ROM DISC #1 1997, PROCEED TO THE SPECIFIC DTC LISTED BELOW AND FOLLOW THE INSTRUCTIONS FOR THAT DTC COMPLETELY.

***IMPORTANT: ALL DTCS, TECHNICIAN OBSERVATIONS, AND CUSTOMER COMMENTS ARE TO BE RECORDED ON THE REPAIR ORDER IN ACCORDANCE WITH ARTICLE 1.6.2G OF THE GENERAL MOTORS SERVICE POLICIES AND PROCEDURES MANUAL.

- FOR O2 HEATER DTCS **P0135, P0141, P0147, P0155**: VERIFY O2 HEATER OPERATION USING THE SERVICE MANUAL SECTION 6E DTC DIAGNOSTIC CHART CODES. FOLLOW THE DTC DIAGNOSTIC CHART UNTIL THE HEATER FAULT IS NOT PRESENT. UPDATE THE PCM WITH APPLICABLE CALIBRATION; DO **NOT** CHANGE THE OXYGEN SENSOR.

- FOR O2 RESPONSE AND RATIO DTCS **P0133, P0153, P1134, P1154**: * VERIFY O2 HEATER OPERATION USING THE SERVICE MANUAL SECTION 6E DIAGNOSTIC CHART CODES. FOLLOW THE DTC DIAGNOSTIC CHART TO THE POINT IT BECOMES NECESSARY TO REPLACE THE OXYGEN SENSOR. UPDATE PCM WITH APPLICABLE CALIBRATION; DO **NOT** CHANGE OXYGEN SENSOR. * VERIFY THE REPAIR USING THE TECH II DEVICE.

- FOR O2 RESPONSE RATIO PRE-CONVERTER O2 DTC **P1140**: * VERIFY O2 HEATER OPERATION USING THE SERVICE MANUAL SECTION 6E DIAGNOSTIC CHART CODES. FOLLOW THE DIAGNOSTIC CHART TO THE POINT IT BECOMES NECESSARY TO REPLACE THE OXYGEN SENSOR. UPDATE THE PCM WITH APPLICABLE CALIBRATION; DO **NOT** CHANGE THE OXYGEN SENSOR. * VERIFY THE REPAIR USING THE TECH II DEVICE.

- FOR KNOCK SENSOR MODULE CIRCUIT DTC **PO325**: UPDATE THE PCM WITH THE APPLICABLE CALIBRATION BEFORE USING THE PUBLISHED SERVICE MANUAL DIAGNOSTIC PROCEDURE IF A LOW BATTERY VOLTAGE CONDITION ALONG WITH EXTENDED CRANK CONDITION MAY HAVE BEEN PRESENT DURING THE SETTING OF DTC P0325.

- FOR EGR SYSTEM MALFUNCTION DTC **P0401**: THIS DTC IS MORE LIKELY TO SET BY FREQUENT VEHICLE HOT RESTARTS IN HIGH AMBIENT TEMPERATURES. VERIFY THERE ARE NO INDUCTION SYSTEM LEAKS. IF NO INDUCTION SYSTEM LEAKS ARE FOUND, PROCEED TO THE SERVICE MANUAL DTC DIAGNOSTIC CHART. IF, AT STEP 7 OF THE DTC DIAGNOSTIC CHART, THE ANSWER IS "YES," UPDATE PCM WITH THE APPLICABLE CALIBRATION.

- FOR **SURGE**: IF A VEHICLE EXHIBITS SURGE AT LOW SPEEDS OF 30 TO 35 MPH UNDER LIGHT LOAD CONDITIONS OR AT THE 1-2 SHIFT UNDER MINIMAL THROTTLE, UPDATE THE PCM WITH THE APPLICABLE ENHANCED CALIBRATION.

PARTS INFORMATION:

AFTER FOLLOWING THE SPECIFIC INSTRUCTIONS OUTLINED ABOVE AND/OR THE NECESSARY PROCEDURES IN THE SERVICE MANUAL HAVE BEEN PERFORMED INDICATE THAT A CALIBRATION ENHANCEMENT IS REQUIRED, UPDATE THE VEHICLE WITH THE APPLICABLE ENHANCED CALIBRATION LISTED BELOW:

OLD CAL. NEW CAL. ENGINE NUMBER NUMBER RPO DESCRIPTION -------- -------- ------ ----------- 16244126 16256586 LD8 U.S. BASE CADILLAC DEVILLE/ELDORADO/ SEVILLE SLS 16244136 16256596 LD8 EUROPEAN EXPORT SEVILLE 16244146 16256606 LD8 U.S. NOISE CONTROL SEVILLE/MEXICAN DEVILLE 16244756 16256616 L37 U.S. CADILLAC ETC/STS WITH "Z" TIRES 16244766 16256626 L37 U.S. CADILLAC ETC/STS CONCOURS WITH "H" TIRES 16245336 16256636 L37 EXPORT UNLEADED CADILLAC ETC/STS WITH "Z" TIRES 16245346 16256646 L37 EXPORT NOISE CONTROL CADILLAC ETC//STS 16245386 16256656 L47 CANADIAN OLDSMOBILE AURORA 16244736 16256666 L47 U.S. OLDSMOBILE AURORA 16244746 16256676 L47 U.S. OLDSMOBILE AURORA WITH FV4 OPTION 16245396 16256686 L47 CANADIAN OLDSMOBILE AURORA WITH FV4 OPTION 16244216 16256696 LD8 CANADIAN BASE CADILLAC DEVILLE/ELDORADO/ SEVILLE SLS 16245406 16256706 L37 CANADIAN CADILLAC ETC/STS/CONCOURS WITH "H" TIRES 16245416 16256716 L37 CANADIAN CADILLAC ETC/STS WITH "Z" TIRES 16256896 LD8 U.S. CADILLAC LIMOUSINE/FUNERAL COACH

WARRANTY INFORMATION FOR 1997 CADILLAC CONCOURS, DEVILLE, ELDORADO, SEVILLE, COMMERCIAL CHASSIS, AND OLDSMOBILE AURORA MODELS REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION DESCRIPTION LABOR TIME --------- ----------- ---------- J6355 PROM, REPROGRAMMING ON CAR 0.4 HOUR

FIGURES: 0 ATTACHMENTS: 0

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS, NOT A "DO-IT-YOURSELFER". THEY ARE WRITTEN TO INFORM THOSE TECHNICIANS OF CONDITIONS THAT MAY OCCUR ON SOME VEHICLES, OR TO PROVIDE INFORMATION THAT COULD ASSIST IN THE PROPER SERVICE OF A VEHICLE. PROPERLY TRAINED TECHNICIANS HAVE THE EQUIPMENT, TOOLS, SAFETY INSTRUCTIONS AND KNOW-HOW TO DO A JOB PROPERLY AND SAFELY. IF A CONDITION IS DESCRIBED, DO NOT ASSUME THAT THE BULLETIN APPLIES TO YOUR VEHICLE, OR THAT YOUR VEHICLE WILL HAVE THAT CONDITION. SEE A GENERAL MOTORS DEALER SERVICING YOUR BRAND OF GENERAL MOTORS VEHICLE FOR INFORMATION ON WHETHER YOUR VEHICLE MAY BENEFIT FROM THE INFORMATION.