REDUCED RANGE OR DISABLED CHARGING (REPLACE HTCM,

SUBJECT: REDUCED RANGE OR DISABLED CHARGING (REPLACE HTCM, INSTALL HOSE CONNECTOR/ELBOW)

MODELS: 1997-98 CHEVROLET S-10 ELECTRIC TRUCK

CONDITION:

SOME OWNERS MAY COMMENT ON ONE OF THE FOLLOWING CONDITIONS:

1. REDUCED VEHICLE RANGE 2. CHARGING DISABLED IF CHARGED BETWEEN -1 TO 3 DEGREES C (31 TO 37 DEGREES F) 3. CHARGING DISABLED 4. CHARGE RECEPTACLE OVERHEATING

CAUSE:

THE OLD HVAC THERMAL CONTROL MODULE (HTCM) SOFTWARE AND CALIBRATION MAY NOT BE ADEQUATE FOR SOME AMBIENT TEMPERATURE CONDITIONS ENCOUNTERED DURING CUSTOMER USE AND VEHICLE SERVICE. THE CHARGE PORT MAY OVERHEAT BECAUSE OF LACK OF COOLANT TO THE CHARGE PORT.

CORRECTION:

REPLACE THE HTCM. ON TRUCKS EQUIPPED WITH A CHARGE RECEPTACLE COOLANT VALVE, INSTALL A HOSE CONNECTOR (ELBOW). USE THE PART NUMBER LISTED BELOW. USE THE FOLLOWING SERVICE PROCEDURE.

SERVICE PROCEDURE -

HTCM REPLACEMENT:

1. REMOVE THE SEAT IN ORDER TO ACCESS THE HTCM. REFER TO HTCM REMOVAL AND INSTALLATION IN THE BODY SECTION OF THE S-10 ELECTRIC SERVICE MANUAL.

2. PULL BACK THE FLOOR MAT IN ORDER TO EXPOSE THE HTCM. DISCONNECT BOTH OF THE HTCM CONNECTORS (FIGURE 3).

3. APPLY A HOOK AND LOOP FASTENER TO THE NEW HTCM IN THE SAME LOCATIONS AS THE PREVIOUS HTCM. CONNECT BOTH CONNECTORS TO THE NEW HTCM AND PRESS THE HTCM FIRMLY INTO THE HOOK AND LOOP FASTENER ON THE FLOOR (FIGURE 1).

4. REINSTALL THE FLOOR MAT.

5. REINSTALL THE SEAT. REFER TO SEAT REPLACEMENT IN THE BODY SECTION OF THE 1998 S-10 ELECTRIC TRUCK SERVICE MANUAL.

COOLANT HOSE CONNECTOR (ELBOW) INSTALLATION:

IMPORTANT: ONLY DO THIS PROCEDURE IF THE TRUCK IS EQUIPPED WITH A CHARGE RECEPTACLE COOLANT VALVE.

1. REMOVE THE AUXILIARY HEATER COOLANT RECOVERY TANK AND PLACE THE TANK ASIDE (FIGURE 2).

2. REMOVE THE THREE 7 MM RETAINING SCREWS FROM THE CHARGE RECEPTACLE COOLANT VALVE.

3. USING HEATER HOSE CLAMP TOOL J 38543, OR EQUIVALENT, CLAMP OFF BOTH HOSES THAT CONNECT TO THE CHARGE RECEPTACLE COOLANT VALVE.

4. USING HOSE CLAMP PLIERS J 38185, OR EQUIVALENT, SLIDE THE COOLANT HOSE CLAMPS BACK FROM THE CHARGE RECEPTACLE COOLANT VALVE AND DISCONNECT THE HOSES.

5. REMOVE AND DISCARD THE VALVE (FIGURE 4).

6. INSTALL THE COOLANT HOSE CONNECTOR AND REINSTALL THE COOLANT HOSE CLAMPS (FIGURE 5).

7. REMOVE THE HOSE CLAMP TOOLS FROM THE COOLANT HOSES.

8. USING ELECTRICAL TAPE, COVER THE HARNESS CONNECTOR FOR THE CHARGE RECEPTACLE COOLANT VALVE.

9. INSTALL THE AUXILIARY HEATER COOLANT RECOVERY TANK.

10. TURN ON THE VEHICLE FOR 2 MINUTES IN ORDER TO CIRCULATE THE COOLANT THROUGH THE SYSTEM. ADD COOLANT TO THE RECOVERY TANK IF NECESSARY.

PARTS INFORMATION:

P/N DESCRIPTION QTY --- ------------ ---

27004713 KIT, HTCM MODULE SERVICE 1 (1997 HTCM)

27004714 KIT, HTCM MODULE SERVICE 1 (1998 HTCM)

12378390 ELECTRA-COOL COOLANT 1

27002705 DUAL-LOCK, HTCM MOUNTING 2

PARTS ARE EXPECTED TO BE AVAILABLE 10-1-98 FROM GMSPO.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION DESCRIPTION LABOR TIME --------- ----------- ----------

D2226 MODULE ASSEMBLY, BLOWER MTR USE PUBLISHED LABOR AND A/C COMP CONTROL - REPLACE OPERATION TIME

ADD: FOR REPLACING COOLANT 0.4 HR CONTROL VALVE

IMPORTANT: LABOR OPERATION IS CODED TO BASE VEHICLE COVERAGE IN THE WARRANTY SYSTEM.

FIGURES: 05 CAPTIONS: FIG.1-HTCM FASTENING FIG.2-HEATER COOLANT RECOVERY TANK FIG.3-HTCM LOCATION FIG.4-CHARGE RECEPTACLE COOLANT VALVE FIG.5-COOLANT HOSE CONNECTOR

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.

COPYRIGHT 1998 GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.