SMU - SECTION 9J - REVISED DIAGNOSTIC CHART

REVISION: 11/13/95

THIS BULLETIN IS BEING REVISED TO ADD INFORMATION TO THE TITLE. **********************************************************************

SUBJECT: SERVICE MANUAL UPDATE - SECTION 9J - SUPPLEMENTAL INFLATABLE RESTRAINT - REVISED DIAGNOSTIC CHARTS AND ON-VEHICLE SERVICE PROCEDURES

MODELS: 1995 CHEVROLET CAVALIER 1995 PONTIAC SUNFIRE

THIS BULLETIN REVISES INFORMATION IN SECTION 9J, PAGES 9J-11, 37, 47, 60, 61, 63, 96, 97, 99 AND 100 OF THE SERVICE MANUAL (GMP/95-J-1).

PLEASE UPDATE THE SERVICE MANUAL WITH THE FOLLOWING REVISIONS:

1. SIR DIAGNOSTIC SYSTEM CHECK CHART (PAGE 9J-11) - CHART HAS BEEN REVISED (SEE ATTACHMENT #1).

2. DTC 21 CHART (PAGE 9J-37) - CHART HAS BEEN REVISED (SEE ATTACHMENT #2).

3. DTC 24 CHART (3 OF 3), (PAGE 9J-47) - CHART HAS BEEN REVISED (SEE ATTACHMENT #3).

4. DTC 35 "DISCRIMINATING SENSOR OPEN OR MISSING", (PAGE 9J-60) AND DTC 35 CHART (PAGE 9J-61) - REVISED TEXT, AS FOLLOWS, AND REVISED DTC 35 CHART (SEE ATTACHMENT #4).

CIRCUIT DESCRIPTION:

DURING NORMAL, NON-DEPLOYMENT OPERATION OF THE SIR SYSTEM, A SMALL AMOUNT OF CURRENT FLOWS THROUGH BOTH THE DRIVER AND PASSENGER DEPLOYMENT LOOPS. THE DIAGNOSTIC RESISTORS WITHIN THE DUAL POLE ARMING SENSOR AND THE DISCRIMINATING SENSORS, ALONG WITH THE RESISTANCE OF THE INFLATOR MODULES, CAUSE VOLTAGE DROPS WITHIN THE DEPLOYMENT LOOPS. THE DERM MONITORS THE VOLTAGE AT "DRIVER SIDE LOW" TERMINAL "B8" AND "PASSENGER SIDE LOW" TERMINAL "B7" TO DETECT SHORTS OR OPENS WITHIN THE DEPLOYMENT LOOPS. WHEN THE MEASURED VOLTAGE AT EITHER TERMINAL IS WITHIN A SPECIFIED PERCENTAGE OF ITS RESPECTIVE "36 VLR" POWER SUPPLY VOLTAGE FOR 500 MILLISECONDS, DTC 35 IS SET.

DTC WILL SET WHEN:

THE VOLTAGE MEASURED AT "DRIVER SIDE LOW" TERMINAL "B8" OR AT "PASSENGER SIDE LOW" TERMINAL "B7" IS WITHIN A SPECIFIED PERCENTAGE OF ITS RESPECTIVE "36 VLR" POWER SUPPLY VOLTAGE FOR 500 MILLISECONDS. THIS TEST IS RUN EVERY 100 MILLISECONDS DURING THE "CONTINUOUS MONITORING" TESTS.

ACTION TAKEN:

DERM SETS A DIAGNOSTIC TROUBLE CODE AND SENDS A COMMAND TO THE INSTRUMENT CLUSTER TO TURN "ON" THE "AIR BAG" WARNING LAMP.

DTC WILL CLEAR WHEN:

THE VOLTAGES MEASURED AT "DRIVER SIDE LOW" TERMINAL "B8" AND "PASSENGER SIDE LOW" TERMINAL "B7" ARE BOTH ABOVE OR BELOW THE PERCENTAGE OF THEIR RESPECTIVE "36 VLR" POWER SUPPLY VOLTAGE WHICH SETS DTC 35.

DTC CHART TEST DESCRIPTION:

NUMBER(S) BELOW REFER TO CIRCLED NUMBER(S) ON THE DIAGNOSTIC CHART:

1. THIS TEST CHECKS FOR INCREASED RESISTANCE IN THE PASSENGER COMPARTMENT DISCRIMINATING SENSOR. 2. THIS TEST CHECKS FOR AN OPEN GROUND FEED TO THE PASSENGER COMPARTMENT DISCRIMINATING SENSOR. 3. THIS TEST CHECKS FOR INCREASED RESISTANCE IN THE FORWARD DISCRIMINATING SENSOR. 4. THIS TEST CHECKS FOR AN OPEN GROUND FEED TO THE FORWARD DISCRIMINATING SENSOR. 5. THIS TEST CHECKS FOR AN OPEN IN CKT 349. 6. THIS TEST CHECKS FOR DECREASED RESISTANCE IN THE DIAGNOSTIC RESISTORS IN THE DUAL POLE ARMING SENSOR.

DIAGNOSTIC AIDS:

AN INTERMITTENT CONDITION IS LIKELY TO BE AN IMPROPER CONNECTION AT EITHER OF THE DISCRIMINATING SENSOR TERMINALS, AN OPEN IN EITHER GROUND FEED TO THE DISCRIMINATING SENSORS, A MALFUNCTIONING DUAL POLE ARMING SENSOR OR A MALFUNCTIONING DISCRIMINATING SENSOR.

5. DTC 36 CHART (PAGE 9J-63) - CHART HAS BEEN REVISED (SEE ATTACHMENT #5).

6. "ON-VEHICLE SERVICE, DIAGNOSTIC ENERGY RESERVE MODULE" (PAGES 9J- 96 AND 9J-97) - USE THE FOLLOWING REVISED "REMOVE OR DISCONNECT/ INSTALL OR CONNECT" PROCEDURE.

(SEE FIGURE #1)

CAUTION:

THE FOLLOWING PROCEDURES MUST BE FOLLOWED IN ORDER LISTED TO TEMPORARILY DISABLE THE SUPPLEMENTAL INFLATABLE RESTRAINT (SIR) SYSTEM AND PREVENT FALSE DIAGNOSTIC TROUBLE CODES FROM SETTING. FAILURE TO FOLLOW PROCEDURES COULD RESULT IN POSSIBLE AIR BAG DEPLOYMENT, PERSONAL INJURY OR OTHERWISE UNNEEDED SIR SYSTEM REPAIRS.

NOTICE: DO NOT OPEN THE DERM CASE FOR ANY REASON AS TOUCHING THE CONNECTOR PINS OR SOLDERED COMPONENTS MAY CAUSE ELECTROSTATIC DISCHARGE DAMAGE. REPAIR OF A MALFUNCTIONING DERM IS BY REPLACEMENT ONLY.

REMOVE OR DISCONNECT:

- DISABLE THE SIR SYSTEM. REFER TO "DISABLING THE SIR SYSTEM" IN THIS SECTION.

1. SCREWS (4) SECURING FRONT CONSOLE TRIM PLATE AND TRIM PLATE. REFER TO SECTION 8C-2.

2. C-CLIP FROM SHIFTER HANDLE AND SHIFTER HANDLE.

3. SCREWS (4) SECURING CONSOLE AND CONSOLE. REFER TO SECTION 8C-2.

4. REPOSITION FRONT CARPET TO ACCESS HVAC AIR TAKE DOWN DUCT AND REAR OUTLET DUCTS.

5. HVAC AIR TAKE DOWN DUCT AND REAR OUTLET DUCTS. REFER TO SECTION 1A.

6. CONNECTOR POSITION ASSURANCE (CPA) AND DERM HARNESS CONNECTOR FROM DERM.

7. RELEASE PLASTIC CLIPS SECURING DERM, DERM FROM VEHICLE.

INSTALL OR CONNECT:

1. DERM TO VEHICLE, ENGAGING FOUR PLASTIC CLIPS.

2. DERM HARNESS CONNECTOR TO DERM AND CPA.

3. HVAC REAR OUTLET DUCTS AND AIR TAKE DOWN DUCT. REFER TO SECTION 1A.

4. REPOSITION CARPET TO ORIGINAL POSITION.

5. CONSOLE AND SCREWS (4) SECURING IT. REFER TO SECTION 8C-2.

6. SHIFTER HANDLE AND C-CLIP SECURING SHIFTER HANDLE.

7. FRONT CONSOLE TRIM PLATE AND SCREWS (4) SECURING IT.

- ENABLE THE SIR SYSTEM, REFER TO "ENABLING THE SIR SYSTEM" IN THIS SECTION.

7. "ON-VEHICLE SERVICE, DUAL POLE ARMING SENSOR" (PAGES 9J-99 AND 9J-100) - USE THE FOLLOWING REVISED "REMOVE OR DISCONNECT/INSTALL OR CONNECT" PROCEDURE.

CAUTION:

DURING SERVICE PROCEDURES, BE VERY CAREFUL WHEN HANDLING A SENSOR. NEVER STRIKE OR JAR A SENSOR. UNDER SOME CIRCUMSTANCES, IT COULD CAUSE DEPLOYMENT AND RESULT IN PERSONAL INJURY OR IMPROPER OPERATION OF THE SUPPLEMENTAL INFLATABLE RESTRAINT (SIR) SYSTEM. ALL SENSORS AND MOUNTING BRACKET BOLTS MUST BE CAREFULLY TORQUED TO ASSURE PROPER OPERATION. PROPER OPERATION OF THE DUAL POLE ARMING SENSOR REQUIRES THE SENSOR BE RIGIDLY ATTACHED TO THE VEHICLE STRUCTURE AND THAT THE ARROW ON THE SENSOR BE POINTING TOWARD THE FRONT OF THE VEHICLE. NEVER POWER UP THE SIR SYSTEM WHEN ANY SENSOR IS NOT RIGIDLY ATTACHED TO VEHICLE, SINCE THE SENSOR COULD BE ACTIVATED WHEN NOT ATTACHED AND COULD RESULT IN DEPLOYMENT.

REMOVE OR DISCONNECT:

- DISABLE THE SIR SYSTEM. REFER TO "DISABLING THE SIR SYSTEM" IN THIS SECTION.

1. REMOVE DERM, REFER TO "DIAGNOSTIC ENERGY RESERVE MODULE" IN THIS SECTION.

2. USING A PAIR OF VISE-GRIP TYPE PLIERS, LOOSEN AND REMOVE THREADED DUCT PIN FROM REAR OF DERM MOUNTING BRACKET. REFER TO FIGURE #1, DERM BRACKET FROM VEHICLE.

3. CONNECTOR POSITION ASSURANCE (CPA) AND ELECTRICAL CONNECTOR.

4. SENSOR FASTENERS.

5. DUAL POLE ARMING SENSOR FROM VEHICLE.

IMPORTANT: - THE FOLLOWING REPAIR PROCEDURES SHOULD ONLY BE UTILIZED IN THE EVENT THAT SENSOR MOUNTING HOLES OR FASTENERS ARE DAMAGED TO THE EXTENT THAT THE SENSOR CAN NO LONGER BE PROPERLY MOUNTED.

- IT IS IMPORTANT THAT THE FASTENERS DO NOT HAVE ANY OIL OR OTHER FOREIGN MATERIAL ON THEM. OIL WILL DAMAGE THE PLASTIC ON THE I/P CONSOLE.

REPAIR:

INSTALL A 6MM BOLT, ORIGINAL FASTENER, IF THE EXTRUDED HOLE IS INTACT, OR A 7MM BOLT IF THE HOLE IS STRIPPED.

TIGHTEN:

FASTENER TO 5.5 N.M (48 LB IN).

INSTALL OR CONNECT:

NOTICE: REFER TO "NOTICE" ON PAGE 9J-1.

1. DUAL POLE ARMING SENSOR TO VEHICLE, ENSURE ARROW IS POINTING TOWARD THE FRONT OF THE VEHICLE.

2. SENSOR FASTENERS.

TIGHTEN:

- FASTENERS TO 5.5 N.M (48 LB IN).

3. ELECTRICAL CONNECTOR AND CPA.

4. DERM BRACKET TO VEHICLE. THREADED DUCT PIN THROUGH REAR OF DERM MOUNTING BRACKET AND THREAD INTO TUNNEL BRACKET. REFER TO FIGURE #1. TIGHTEN USING A PAIR OF VISE-GRIP TYPE PLIERS.

5. INSTALL DERM, REFER TO "DIAGNOSTIC ENERGY RESERVE MODULE" IN THIS SECTION.

- ENABLE THE SIR SYSTEM, REFER TO "ENABLING THE SIR SYSTEM" IN THIS SECTION.

FIGURES: 01 ATTACHMENTS: 05

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