HVAC Systems - Automatic: Diagnosis Chrysler LHS II

SELF-DIAGNOSTICS

Note. There may be DTCs stored in Powertrain Control Module (PCM) that are not related to ATC system DTCs which are stored in Body Control Module (BCM). There are some PCM DTCs that identify problems affecting ATC system operation.

RETRIEVING DIAGNOSTIC TROUBLE CODES

1. Diagnostic Trouble Codes (DTCs) related to the ATC system are stored in the Body Control Module (BCM). Any BCM DTC present, will be displayed on ATC control head display when in-vehicle calibration and DTC check is completed. See «IN-VEHICLE CALIBRATION & DTC CHECK»(ref-211-S37766020892000030800000) under ADJUSTMENTS. ATC control head will display a two-digit DTC. See «IDENTIFYING DIAGNOSTIC TROUBLE CODES»(ref-211-S11367505162000030800000) table. If system is okay and there are no system DTCs present, system will return to normal operation.
2. There are certain conditions in which more than one ATC system DTC can be stored in BCM. ATC control head display can show only one DTC at a time. Press panel mode button to scroll through any additional DTCs. If any other button or selector is moved or pushed, additional DTCs will not be displayed. To exit in-vehicle calibration DTC check, turn ignition off.

Note. If in-vehicle temperature sensor is disconnected while Body Control Module (BCM) is operating, DTC 26 will set. This can occur when BCM or ATC control head connectors are disconnected when battery is connected (even with ignition off). To correct condition, clear DTC 26 from BCM. See CLEARING DIAGNOSTIC TROUBLE CODES .

CLEARING DIAGNOSTIC TROUBLE CODES

DTCs can be cleared from BCM memory using a scan tool or by disconnecting negative battery cable remote terminal for 10 minutes. (Scheme 1) Negative battery cable remote terminal is located on right strut tower. If using a scan tool to clear DTCs, refer to scan tool manufacturer instructions.

IDENTIFYING DIAGNOSTIC TROUBLE CODES

Scheme 1

TESTING

A/C SYSTEM CHARGE LEVEL TEST

There are 2 methods for performing this procedure. The first method involves the use of a scan tool and a clamp-on Thermocouple (80PK-1A). Set scan tool to LH CLIMATE CONTROL, SYSTEM TEST and PARTIAL CHARGE TEST. See SCAN TOOL METHOD .

The second method uses a manifold gauge set, a clamp-on thermocouple, and REFRIGERANT CHARGE LEVEL table. See MANIFOLD GAUGE SET METHOD .

Scan Tool Method

1. Attach clamp-on thermocouple to liquid line, as close to condenser outlet as possible. Attach scan tool to Data Link Connector (DLC), located right of steering column, under instrument panel. (Scheme 2)
2. Set parking brake, and place transaxle in Park position. Start engine and allow to idle. Set A/C controls to outside air, panel mode, full cool, and high blower speed. Turn A/C on, and open windows. Operate system for a few minutes to allow system to stabilize.
3. Place cardboard over front grille area, to block airflow through part of condenser, to set A/C pressure to 260 psi (18.3 kg/cm 2 ). This will stop cooling fans from alternating speeds and maintain constant pressure.
4. Scan tool will automatically calculate system charge. Depending on system charge condition, corrections are made 2 ounces at a time. Each time a correction is made, recheck readings to ensure proper charge. Total system refrigerant capacity is 28 ounces.

Visual Inspection

A careful and thorough visual inspection of components may quickly identify cause of malfunction and eliminate need for diagnostic testing.

Check wiring harnesses and A/C-heater system-related components for damaged or disconnected connectors. Ensure all relays are properly installed in Power Distribution Center (PDC) and junction block. PDC is located on left side of engine compartment. Junction block is located behind end cover, at left side of instrument panel.

Test Equipment Required

To perform diagnostic tests, the following equipment is required.

1. DRB (Diagnostic Readout Box) Or Scan Tool
2. Diagnostic Program Cartridge
3. Body Diagnostic Cable
4. High Impedance Digital Volt-Ohmmeter (DVOM)
5. Fused Jumper Wires

Diagnostic Procedure

1. To properly diagnose and test ATC system, ALWAYS start diagnosis at «TEST 1A: IDENTIFYING ATC SYSTEM PROBLEMS»(ref-211-S09989412222000030800000) . Starting with any other test may result in incorrect diagnosis. Ensure battery is fully charged and charging system is functional. A minimum of 11 volts is required for proper DRB operation.
2. DO NOT backprobe connectors unless specified. Probe connector terminals carefully. DO NOT spread terminals. This could cause an intermittent problem. DO NOT cause short circuits when performing electrical tests. Doing so will set additional fault codes, making diagnosis of original problem more difficult.
3. Use scan tool voltmeter, unless instructed to use an external voltmeter. DO NOT use a test light in place of a voltmeter. Use scan tool ohmmeter, unless instructed to use an external ohmmeter. Always perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) after repairs are made. Always turn ignition off and disconnect scan tool after use.

Note. Because scan tool is grounded through Data Link Connector (DLC), only one volt-ohmmeter test lead is required when using scan tool volt-ohmmeter option. Use an external volt-ohmmeter only when specified by diagnostic procedure.

TEST 1A: IDENTIFYING ATC SYSTEM PROBLEMS

1. Turn ignition off. Connect scan tool to Data Link Connector (DLC). (Scheme 2) Using scan tool and the most current diagnostic program cartridge, ensure there is communication with Body Control Module (BCM) and Powertrain Control Module (PCM). If scan tool has a blank screen, go to next step. If any other communication problem exists, go to appropriate BODY CONTROL COMPUTER article in ACCESSORIES & EQUIPMENT. If there are no communication problems, go to step 7.
2. Turn ignition off. Disconnect scan tool from DLC. Check connector for an open, loose, or disconnected terminal. Repair as necessary.
3. Using a DVOM, ensure that there is continuity between ground and DLC terminals No. 4 (Black wire) and No. 5 (Black/Light Green wire). If continuity is present, go to next step. If continuity is not present, repair wire(s) as necessary.
4. Using a DVOM, check voltage at DLC terminal No. 16 (Pink wire). If battery voltage is not present, go to next step. If battery voltage is present, go to step 6.
5. If battery voltage is not present, check fuse No. 19 (10-amp) located in junction block, behind end cover at left side of instrument panel. (Scheme 3)and (Scheme 4). Replace fuse if blown. If fuse blows again, repair DLC battery feed circuit as necessary.
6. Substitute scan tool cable with a known-good cable. If scan tool screen is no longer blank and scan tool is functioning properly, go to next step. If scan tool screen is still blank, replace defective scan tool. If there are no communication problems, go to next step.
7. Using scan tool, select ENGINE and then READ DTCS. If scan tool does not display any PCM DTCs, go to next step. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE, if any of the following A/C-heater system related PCM DTCs are displayed: ECT SENSOR VOLTAGE TOO LOW ECT SENSOR VOLTAGE TOO HIGH A/C PRESSURE SENSOR VOLTAGE TOO HIGH A/C PRESSURE SENSOR VOLTAGE TOO LOW LOW SPEED FAN CONTROL RELAY CIRCUIT HIGH SPEED FAN CONTROL RELAY CIRCUIT A/C CLUTCH RELAY CIRCUIT ENGINE IS COLD TOO LONG
8. Using scan tool, select BODY SYSTEM, BODY COMPUTER, SENSORS and then IGNITION VOLTAGE. Turn ignition on. If battery voltage is displayed, go to next step. If battery voltage is not displayed, go to appropriate BODY CONTROL COMPUTER article in ACCESSORIES & EQUIPMENT.
9. Using scan tool, select BODY SYSTEM, BODY COMPUTER, and then READ DTCS. If ATC system related BCM DTCs are not present, go to next step. If ATC system related BCM DTCs are present, go to «TEST 1B: IDENTIFYING ATC SYSTEM BCM DIAGNOSTIC TROUBLE CODES»(ref-211-S17498362982000030800000).
10. Using scan tool, select BODY SYSTEM, and then AUTO TEMP CTRL. If scan tool does not display NO RESPONSE, go to next step. If scan tool displays NO RESPONSE, see appropriate BODY CONTROL COMPUTER - VEHICLE COMMUNICATIONS article in ACCESSORIES & EQUIPMENT.
11. If no BCM DTCs exist and any ATC control head switch is inoperative, go to «TEST 2A: INOPERATIVE ATC CONTROL HEAD SWITCH»(ref-211-S32159094582000030800000). If no BCM DTCs exist and recirculation door is inoperative, go to «TEST 12A: RECIRCULATION DOOR ACTUATOR STALL TEST FAILURE»(ref-211-S04860408272000030800000).
12. If no BCM DTCs exist and there is a problem with A/C clutch operation, go to «TEST 14A: COMPRESSOR CLUTCH CIRCUIT»(ref-211-S21666488082000030800000). If no BCM DTCs exist and temperature control/blend air door is inoperative, go to «TEST 15A: INOPERATIVE TEMPERATURE/BLEND AIR DOOR»(ref-211-S14558780642000030800000).
13. If no BCM DTCs exist and blower motor is inoperative, go to «TEST 16A: INOPERATIVE BLOWER MOTOR»(ref-211-S05779561612000030800000). If no BCM DTCs exist and blower motor speed(s) are incorrect, go to «TEST 17A: INCORRECT BLOWER MOTOR SPEEDS»(ref-211-S16429546392000030800000).
14. If no BCM DTCs exist and there is a problem with ATC control head illumination, but instrument panel lights operate properly, go to «TEST 18A: ATC CONTROL HEAD ILLUMINATION»(ref-211-S41790365822000030800000). If no BCM DTCs exist and mode door is inoperative, go to «TEST 19A: INOPERATIVE MODE DOOR»(ref-211-S07878435822000030800000). If no BCM DTCs exist and temperature control is incorrect in sun or shade, go to «TEST 21A: INCORRECT TEMPERATURE CONTROL IN SUN OR SHADE»(ref-211-S23762737512000030800000).
15. If instrument panel lights do not operate properly, see ILLUMINATION/INTERIOR LIGHTS article in ACCESSORIES & EQUIPMENT. If rear window defogger is inoperative, see appropriate REAR WINDOW DEFOGGER article in ACCESSORIES & EQUIPMENT.

Scheme 2

TEST 1B: IDENTIFYING ATC SYSTEM BCM DIAGNOSTIC TROUBLE CODES

Note. Before proceeding with this test perform TEST 1A: IDENTIFYING ATC SYSTEM PROBLEMS .

1. Record and clear Diagnostic Trouble Codes (DTCs). See «RETRIEVING DIAGNOSTIC TROUBLE CODES»(ref-211-S09304415412000030800000) and «CLEARING DIAGNOSTIC TROUBLE CODES»(ref-211-S36194532182000030800000) . Set ATC temperature to 75°F. Start engine. Using scan tool, select BODY COMPUTER and then READ DTCS. If no BCM DTC is present, go to next step. If any BCM DTCs are present, perform appropriate test. See «DIAGNOSTIC TROUBLE CODES DIRECTORY»(ref-211-S02767596202000030800000) table.
2. Using temperature control buttons, slowly change temperature from 65°F to 85°F and back to 65°F while checking for DTCs. If no BCM DTCs are present, go to next step. If any BCM DTCs are present perform appropriate test. See «DIAGNOSTIC TROUBLE CODES TEST DIRECTORY»(ref-211-S02767596202000030800000) table.
3. Continue slowly changing temperature from 60°F to 90°F and back to 60°F. Press each mode and temperature button one at a time, waiting 30 seconds between each one and check for BCM DTCs. If no BCM DTCs are displayed, go to next step. When first BCM DTC is displayed, erase DTC and perform appropriate test. See «DIAGNOSTIC TROUBLE CODES TEST DIRECTORY»(ref-211-S02767596202000030800000) table.
4. Recalibrate doors by pressing and holding floor, mix and defrost buttons at the same time until ATC control head display begins to blink. Release buttons and check for DTCs using scan tool. When first BCM DTC is displayed, erase DTC and perform appropriate test. See «DIAGNOSTIC TROUBLE CODES»(ref-211-S02767596202000030800000) table. If no BCM DTCs are displayed, observe ATC system performance and go to appropriate no DTC component test. See «TEST 1A: IDENTIFYING ATC SYSTEM PROBLEMS»(ref-211-S09989412222000030800000) .

Note. If multiple DTCs appear, repair any that relate to a short circuit first. If a short to battery DTC is set, all 4 OUTPUT SHORTED TO BATTERY DTCs will be displayed. If this occurs, all related circuits must be isolated and checked to determine which is at fault. See TEST 5A: BLEND, MODE, RECIRCULATION DOOR OR COMMON OUTPUT SHORTED TO BATTERY VOLTAGE .

DIAGNOSTIC TROUBLE CODES TEST DIRECTORY

TEST 2A: INOPERATIVE ATC CONTROL HEAD SWITCH

Note. Perform TEST 1B: IDENTIFYING ATC SYSTEM BCM DIAGNOSTIC TROUBLE CODES before proceeding with this test. A failed ATC control head switch code will set when a switch is in closed position for 5-10 minutes.

Note. Test each switch, in turn, while switch name is displayed on scan tool. Use appropriate switch name in place of references to SWITCH in following steps. see scheme 1

1. Using scan tool, clear DTCs and select AUTOMATIC TEMP CONTROL, INPUT/OUTPUTS and read ATC SWITCH. If scan tool displays SWITCH: OPEN, go to next step. If scan tool does not display SWITCH: OPEN, replace ATC control head. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
2. Press and hold ATC control head button. Using scan tool, read ATC SWITCH. If scan tool does not display SWITCH: OPEN, switch is operating properly at this time. If scan tool displays SWITCH: OPEN, replace ATC HEAD. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .

TEST 3A: BLEND DOOR FEEDBACK/STALL TEST FAILURE

Note. Perform TEST 1B: IDENTIFYING ATC SYSTEM BCM DIAGNOSTIC TROUBLE CODES before proceeding with this test. DTC 23 will set if BCM detects a loss of signal on mode and/or blend door feedback input. DTC 32 will set if BCM is unable to detect end of travel for mode, blend and/or recirculation doors.

1. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. (Scheme 3) Turn ignition off. Disconnect BCM Black 24-pin connector (C2). Ensure connector terminals are clean and tight. Repair as necessary.
2. Using a DVOM, backprobe BCM connector C2 terminal No. 15 (Pink/Dark Blue wire) and reconnect BCM connector C2. Ensure all BCM connectors are connected. Turn ignition on (engine off) and measure voltage. If voltage is less than 4.0 volts, go to next step. If voltage is 4.0-10.0 volts, go to step 6. If voltage is more than 10.0 volts, repair short to battery voltage in Pink/Dark Blue wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
3. Turn ignition off. Disconnect all BCM connectors. Ensure connector terminals are clean and tight. Using a DVOM, measure resistance between ground and BCM Black 24-pin connector (C2) terminal No. 15 (Pink/Dark Blue wire). If resistance is more than 5.0 ohms, go to next step. If resistance is less than 5.0 ohms, repair short to ground in Pink/Dark Blue wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
4. Using a DVOM, measure resistance between BCM Gray 14-pin connector (C1) terminal No. 8 (Dark Blue/Gray wire) and BCM connector C2 terminal No. 15 (Pink/Dark Blue wire). If resistance is less than 2000.0 ohms, go to next step. If resistance is more than 2000.0 ohms, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
5. Disconnect blend door actuator 5-pin connector, located at left center of A/C-heater assembly. see scheme 2 Ensure connector terminals are clean and tight. Using a DVOM, measure resistance between BCM connector C1 terminal No. 8 (Dark Blue/Gray wire) and BCM connector C2 terminal No. 15 (Pink/Dark Blue wire). If resistance is less than 2000.0 ohms, replace mode door actuator. If resistance is more than 2000.0 ohms, replace blend door actuator. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
6. Using a DVOM, backprobe A/C-heater assembly plenum 16-pin connector terminal No. 6 (Pink/Dark Blue wire), located at left end of A/C-heater assembly. see scheme 2 If voltage is more than 4.0 volts, go to next step. If voltage is less than 4.0 volts, repair open in Pink/Dark Blue wire between plenum 16-pin connector and BCM connector C2 terminal No. 15. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
7. Turn ignition off and disconnect BCM connector C2. Using a DVOM, backprobe BCM connector C2 terminal No. 1 (Red/White wire) and reconnect BCM connector C2. Ensure all BCM connectors are connected. Turn ignition on (engine off) and measure voltage. If voltage is less than 0.3 volt, go to next step. If voltage is 0.3-10.0 volts, go to step 11. If voltage is more than 10.0 volts, repair short to battery voltage in Red/White wire between plenum 16-pin connector terminal No. 10 and BCM connector C2 terminal No. 1. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
8. Using a DVOM, backprobe A/C-heater assembly plenum 16-pin connector terminal No. 10 (Red/White wire). see scheme 2 If voltage is less than 0.3 volt, go to next step. If voltage is 0.3 volt or more, repair open in Red/White wire between plenum 16-pin connector terminal No. 10 and BCM connector C2 terminal No. 1. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
9. Turn ignition off. Disconnect A/C-heater assembly plenum 16-pin connector and BCM connector C2. Ensure connector terminals are clean and tight. Using a DVOM, measure resistance between ground and BCM connector C2 terminal No. 1 (Red/White wire). If resistance is more than 5.0 ohms, go to next step. If resistance is less than 5.0 ohms, repair short to ground in Red/White wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
10. Remove blend air door actuator, and rotate door shaft in both directions. Ensure door moves smoothly and stops at both ends of its travel. Repair as necessary. If blend air door travel is okay, replace door actuator. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
11. Turn ignition off. Close all vehicle doors and wait one minute to ensure courtesy lights are off. Using a DVOM, backprobe A/C-heater assembly plenum 16-pin connector terminal No. 5 (Dark Blue/Gray wire). If resistance is less than 60.0 ohms, go to next step. If resistance is more than 60.0 ohms, go to «TEST 3B: OPEN SENSOR GROUND»(ref-211-S34122177272000030800000).
12. Ensure ignition is off. Disconnect BCM Gray 14-pin connector (C1). Using a DVOM, backprobe BCM connector C1 terminal No. 10 (Brown/White wire) and reconnect BCM connector C1. Ensure all BCM connectors are connected. Turn ignition on (engine off) and observe voltage. Turn recirculation button off, and panel button on. Now turn recirculation button on. If voltage increases to more than 10.0 volts, go to next step. If voltage does not increase to more than 10.0 volts, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
13. Using scan tool, clear all DTCs. Using a DVOM, backprobe A/C-heater assembly plenum 16-pin connector terminal No. 3 (Dark Blue/Red wire). Adjust temperature between full cold and full hot and observe voltage change. If voltage does not increase to more than 10.0 volts, go to next step. If voltage increases to more than 10.0 volts, go to step 15.
14. Turn ignition off. Disconnect BCM Gray 14-pin connector (C1). Using a DVOM, backprobe BCM connector C1 terminal No. 3 (Dark Blue/Red wire) and reconnect BCM connector C1. Ensure all BCM connectors are connected. Turn ignition on (engine off). Adjust temperature between full cold and full hot and observe voltage change. If voltage increases to more than 10.0 volts, repair open in Dark Blue/Red wire circuit between BCM connector C1 and plenum 16-pin connector. If voltage does not increase to more than 10.0 volts, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
15. Turn ignition off. Disconnect BCM Gray 14-pin connector (C1) and plenum 16-pin connector. Ensure connector terminals are clean and tight. Using a DVOM, measure resistance between BCM connector C1 terminal No. 10 (Brown/White wire) and A/C-heater assembly plenum 16-pin connector terminal No. 1 (Brown/White wire). If resistance is less than 5.0 ohms, go to next step. If resistance is more 5.0 ohms, repair open Brown/White wire between BCM connector C1 and plenum connector. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
16. Remove blend air door actuator, and rotate door shaft in both directions. Ensure door moves smoothly and stops at both ends of its travel. Repair as necessary. If blend air door travel is okay, replace door actuator. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).

Scheme 3

TEST 3B: OPEN SENSOR GROUND

Note. Perform TEST 3A: BLEND DOOR FEEDBACK/STALL TEST FAILURE before proceeding with this test.

1. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Gray 14-pin connector (C1). Ensure connector terminals are clean and tight. Repair as necessary.
2. Using a DVOM, backprobe BCM connector C1 terminal No. 8 (Dark Blue/Gray wire). Reconnect BCM connector C1. If resistance is more than 60.0 ohms, go to next step. If resistance is less than 60.0 ohms, repair open in Dark Blue/Gray wire between BCM connector C1 and A/C-heater assembly plenum 16-pin connector terminal No. 5. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
3. Remove BCM and junction block. Separate BCM and junction block and check junction block 20-pin internal connector. Ensure connector terminals are clean and tight. Repair or replace junction block as necessary. If connector terminals are okay, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .

TEST 4A: BLEND DOOR OUTPUT SHORTED TO GROUND

Note. Perform TEST 1B: IDENTIFYING ATC SYSTEM BCM DIAGNOSTIC TROUBLE CODES before proceeding with this test. DTC 38 will set when BCM detects mode door drive, blend air door drive, recirculation door drive, and/or common drive output shorted to ground.

1. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Gray 14-pin connector (C1). Ensure connector terminals are clean and tight. Repair as necessary.
2. Close all vehicle doors and ensure courtesy lights are off. Using a DVOM, measure resistance between ground and BCM connector C1 terminal No. 3 (Dark Blue/Red wire). If resistance is more than 5.0 ohms, replace BCM. If resistance is less than 5.0 ohms, repair short to ground in Dark Blue/Red wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .

TEST 5A: BLEND, MODE, RECIRCULATION DOOR OR COMMON OUTPUT SHORTED TO BATTERY VOLTAGE

Note. Perform TEST 1B: IDENTIFYING ATC SYSTEM BCM DIAGNOSTIC TROUBLE CODES before proceeding with this test. DTCs 37, 39, 41, and 43 will set when BCM detects mode door drive, blend air door drive, recirculation door drive, and/or common drive output shorted to battery voltage.

1. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Gray 14-pin connector (C). Ensure connector terminals are clean and tight. Repair as necessary.
2. Turn ignition on (engine off). Using a DVOM, measure voltage between ground and BCM connector C1 terminal No. 3 (Dark Blue/Red wire). If voltage is less than 10.0 volts, go to next step. If voltage is more than 10.0 volts, repair short to battery voltage in Dark Blue/Red wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
3. Using a DVOM, measure voltage between ground and BCM connector C1 terminal No. 9 (Dark Green/Yellow wire). If voltage is less than 10.0 volts, go to next step. If voltage is more than 10.0 volts, repair short to battery voltage in Dark Green/Yellow wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
4. Using a DVOM, measure voltage between ground and BCM connector C1 terminal No. 2 (Gray/Dark Blue wire). If voltage is less than 10.0 volts, go to next step. If voltage is more than 10.0 volts, repair short to battery voltage in Gray/Dark Blue wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
5. Using a DVOM, measure voltage between ground and BCM connector C1 terminal No. 10 (Brown/White wire). If voltage is less than 10.0 volts, go to next step. If voltage is more than 10.0 volts, repair short to battery voltage in Brown/White wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
6. Turn ignition off. Using a DVOM, measure resistance between BCM connector C1 terminal No. 3 (Dark Blue/Red wire) and BCM connector C1 terminals No. 2 (Gray/Dark Blue wire), No. 9 (Dark Green/Yellow wire), and No. 10 (Brown/White wire). If resistance on all circuits is more than 5.0 ohms, go to next step. If resistance on any circuit is less than 5.0 ohms, repair circuit short to Dark Blue/Red wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
7. Using a DVOM, measure resistance between BCM connector C1 terminal No. 9 (Dark Green/Yellow wire) and BCM connector C1 terminals No. 2 (Gray/Dark Blue wire), No. 3 (Dark Blue/Red wire), and No. 10 (Brown/White wire). If resistance on all circuits is more than 5.0 ohms, go to next step. If resistance on any circuit is less than 5.0 ohms, repair circuit short to Dark Green/Yellow wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
8. Using a DVOM, measure resistance between BCM connector C1 terminal No. 2 (Gray/Dark Blue wire) and BCM connector C1 terminals No. 3 (Dark Blue/Red wire), No. 9 (Dark Green/Yellow wire), and No. 10 (Brown/White wire). If resistance on all circuits is more than 5.0 ohms, go to next step. If resistance on any circuit is less than 5.0 ohms, repair circuit short to Gray/Dark Blue wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
9. Using a DVOM, measure resistance between BCM connector C1 terminal No. 10 (Brown/White wire) and BCM connector C1 terminals No. 2 (Gray/Dark Blue wire), No. 3 (Dark Blue/Red wire), and No. 9 (Dark Green/Yellow wire). If resistance on all circuits is more than 5.0 ohms, replace BCM. If resistance on any circuit is less than 5.0 ohms, repair circuit short to Brown/White wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .

TEST 6A: COMMON OUTPUT SHORTED TO GROUND

Note. Perform TEST 1B: IDENTIFYING ATC SYSTEM BCM DIAGNOSTIC TROUBLE CODES before proceeding with this test. DTC 44 will set when BCM detects mode door drive, blend air door drive, recirculation door drive, and/or common drive output shorted to ground.

1. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Gray 14-pin connector (C1). Ensure connector terminals are clean and tight. Repair as necessary.
2. Close all vehicle doors and ensure courtesy lights are off. Using a DVOM, measure resistance between ground and BCM connector C1 terminal No. 10 (Brown/White wire). If resistance is more than 5.0 ohms, replace BCM. If resistance is less than 5.0 ohms, repair short to ground in Brown/White wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .

TEST 7A: EVAPORATOR TEMPERATURE SENSOR FAILURE

Note. Perform TEST 1B: IDENTIFYING ATC SYSTEM BCM DIAGNOSTIC TROUBLE CODES before proceeding with this test. DTC 35 will set when BCM detects an abnormally high (more than 4.88 volts) or low (less than 0.313 volt) voltage on evaporator temperature sensor.

1. Using scan tool, read evaporator temperature sensor value. If scan tool displays EVAP TEMP: 4.9 VOLTS or more, go to next step. If scan tool does not display EVAP TEMP: 4.9 VOLTS, go to step 7.
2. Locate evaporator temperature sensor on A/C-heater assembly. see scheme 2 Disconnect evaporator temperature sensor connector. Ensure connector is clean and tight. Repair as necessary. Using a DVOM, measure voltage between ground and evaporator temperature sensor connector terminal No. 1 (Light Green/Black wire). If voltage is less than 10.0 volts, go to next step. If voltage is more than 10.0 volts, repair short to battery voltage on Light Green/Black wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
3. Connect a jumper wire between evaporator temperature sensor connector terminals. Using scan tool, read evaporator temperature sensor value. If scan tool displays EVAP TEMP: 4.9 VOLTS or more, disconnect jumper wire and go to next step. If scan tool does not display EVAP TEMP: 4.9 VOLTS, replace evaporator temperature sensor. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
4. Connect jumper wire between ground and evaporator temperature sensor connector Light Green/Black wire. Using scan tool, read evaporator temperature sensor value. If scan tool displays EVAP TEMP: 4.9 VOLTS or more, go to next step. If scan tool does not display EVAP TEMP: 4.9 VOLTS, go to «TEST 7B: EVAPORATOR TEMPERATURE SENSOR FAILURE»(ref-211-S37733415362000030800000).
5. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Black 24-pin connector (C2). Ensure connector terminals are clean and tight. Repair as necessary. Connect a jumper wire between ground and BCM connector C2 terminal No. 20 (Light Green/Black wire).
6. Reconnect BCM connector C2. Using a DVOM, measure resistance between ground and evaporator temperature sensor connector terminal No. 1 (Light Green/Black wire). If resistance is less than 5.0 ohms, replace BCM. If resistance is more than 5.0 ohms, repair open in Light Green/Black wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
7. Locate evaporator temperature sensor on A/C-heater assembly. see scheme 2 Disconnect evaporator temperature sensor connector. Ensure connector is clean and tight. Repair as necessary.
8. Using scan tool, read evaporator temperature sensor value. If scan tool displays EVAP TEMP: 4.9 VOLTS or more, go to step 11. If scan tool does not display EVAP TEMP: 4.9 VOLTS, go to next step.
9. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Black 24-pin connector (C2). Ensure connector terminals are clean and tight. Repair as necessary.
10. Using a DVOM, measure resistance between ground and BCM connector C2 terminal No. 20 (Light Green/Black wire). If resistance is more than 5.0 ohms, replace BCM. If resistance is less than 5.0 ohms, repair short to ground in Light Green/Black wire between BCM and sensor. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
11. Reconnect evaporator temperature sensor connector. Using scan tool, clear BCM DTCs and wait 2 minutes. Using scan tool, read BCM DTCs. If EVAPORATOR SENSOR TEMPERATURE FAILURE DTC 35 does not return, go to next step. If EVAPORATOR SENSOR TEMPERATURE FAILURE DTC 35 returns, replace evaporator temperature sensor. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
12. Ensure all BCM connectors and other disconnected connectors are reconnected. Start engine and operate ATC system for 5 minutes. Using scan tool, read BCM DTCs. If EVAPORATOR SENSOR TEMPERATURE FAILURE DTC 35 does not return, A/C system is operating properly at this time. If EVAPORATOR SENSOR TEMPERATURE FAILURE DTC 35 returns, replace evaporator temperature sensor. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).

TEST 7B: EVAPORATOR TEMPERATURE SENSOR FAILURE

Note. Perform TEST 7A: EVAPORATOR TEMPERATURE SENSOR FAILURE before proceeding with this test.

1. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Gray 14-pin connector (C1). Ensure connector terminals are clean and tight. Repair as necessary.
2. Using a DVOM, backprobe BCM connector C1 terminal No. 8 (Dark Blue/Gray wire). Reconnect BCM connector C1. Ensure all BCM connectors are connected. Close all doors and ensure courtesy lights are off. Wait at least one minute. If resistance is less than 30.0 ohms, go to next step. If resistance is more than 30.0 ohms, repair open in Dark Blue/Gray wire between BCM connector C1 and evaporator temperature sensor connector. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
3. Turn ignition off. Remove BCM and junction block. Separate BCM from junction block. Ensure 20-pin internal connector terminals between junction block and BCM are clean and tight. Repair terminals or replace junction block as necessary. If connector terminals are okay, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .

TEST 8A: ATC IN-VEHICLE TEMPERATURE THERMISTOR FAILURE

Note. Perform TEST 1A: IDENTIFYING ATC SYSTEM PROBLEMS or TEST 1B: IDENTIFYING ATC SYSTEM BCM DIAGNOSTIC TROUBLE CODES before proceeding with this test. DTC 26 will set when BCM detects an abnormally high (more than 4.88 volts) or low (less than 0.313 volt) in-vehicle temperature input.

1. Turn ignition on (engine off). Press ATC control head OFF button to stop ATC system airflow. Cover aspirator fan inlet on ATC control head with a small piece of tissue paper and check aspirator fan motor operation. see scheme 1 If tissue paper sticks to sensor opening, go to next step. If tissue paper does not stick to sensor opening, go to «TEST 8C: ATC ASPIRATOR MOTOR DOES NOT OPERATE»(ref-211-S03011181282000030800000).
2. Turn ignition off. From inside vehicle, close all doors and ensure courtesy lights go off. Wait 3 minutes. Open and close left front door and check aspirator fan motor operation using tissue paper. If aspirator operates for approximately 30 seconds after courtesy lights go out, go to next step. If aspirator does not operate for approximately 30 seconds after courtesy lights go out, go to «TEST 8D: ATC ASPIRATOR MOTOR CONTINUES TO OPERATE»(ref-211-S16911480522000030800000).
3. Turn ignition off. Disconnect ATC control head Black 12-pin connector. Ensure connector terminals are clean and tight. Repair as necessary. Turn ignition on (engine off). Using a DVOM, measure voltage between ground and ATC control head 12-pin connector terminal No. 7 (Red/Tan wire). If voltage is less than 4.0 volts, go to next step. If voltage is more than 10.0 volts, repair short to battery voltage in Red/Tan wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000). If voltage is 4.0-10.0 volts, go to «TEST 8B: ATC ASPIRATOR OR IN-VEHICLE TEMPERATURE SENSOR FAILURE»(ref-211-S02763555572000030800000).
4. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Black 24-pin connector (C2). Ensure connector terminals are clean and tight. Repair as necessary.
5. Using a DVOM, measure resistance between ground and BCM connector C2 terminal No. 22 (Red/Tan wire). If resistance is more than 5.0 ohms, go to next step. If resistance is less than 5.0 ohms, repair short to ground in Red/Tan wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
6. Using a DVOM, backprobe BCM connector C2 terminal No. 22 (Red/Tan wire) and reconnect BCM connector C2. Turn ignition on (engine off) and measure voltage. If voltage is less than 4.0 volts, replace BCM. If voltage is more than 4.0 volts, repair open in Red/Tan wire between in-vehicle temperature sensor and BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).

TEST 8B: ATC ASPIRATOR OR IN-VEHICLE TEMPERATURE SENSOR FAILURE

Note. Perform TEST 8A: ATC IN-VEHICLE TEMPERATURE THERMISTOR FAILURE before proceeding with this test.

1. Turn courtesy light switch off. Turn ignition off, close all doors and wait one minute. Using a DVOM, measure resistance between ground and ATC control head 12-pin connector terminal No. 8 (Dark Blue/Gray wire). If resistance is more than 10.0 ohms, go to next step. If resistance is less than 10.0 ohms, go to step 4 .
2. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Gray 14-pin connector (C1). Ensure connector terminals are clean and tight. Repair as necessary.
3. Using a DVOM, backprobe BCM connector C1 terminal No. 8 (Dark Blue/Gray wire). Reconnect BCM connector C1 and measure resistance. Ensure all BCM connectors are connected. If resistance is more than 10.0 ohms, replace BCM. If resistance is less than 10.0 ohms, repair open in Dark Blue/Gray wire between sensor and BCM connector C1. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
4. Reconnect ATC control head Black 12-pin connector. Using scan tool, clear BCM DTCs. Turn ignition on (engine off). Wait 15 seconds. Using scan tool, read BCM DTCs and go to next step.
5. If scan tool does not display any DTCs, system is operating properly at this time. If scan tool displays any other DTC except ATC IN-CAR TEMP SENSOR FAILURE, go to «TEST 1B: IDENTIFYING ATC SYSTEM BCM DIAGNOSTIC TROUBLE CODES»(ref-211-S17498362982000030800000) . If scan tool displays ATC IN-CAR TEMP SENSOR FAILURE, replace in-vehicle temperature sensor (ATC control head must be replaced). Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .

TEST 8C: ATC ASPIRATOR MOTOR DOES NOT OPERATE

Note. Perform TEST 8A: ATC IN-VEHICLE TEMPERATURE THERMISTOR FAILURE before proceeding with this test.

1. Turn ignition off. Disconnect ATC control head connectors and remove ATC control head. Ensure connector terminals are clean and tight. Repair as necessary.
2. Turn ignition on (engine off). Using a DVOM, measure voltage between ground and ATC control head Black 12-pin connector terminal No. 12 (Pink wire). If voltage is more than 10.0 volts, go to next step. If voltage is less than 10.0 volts, repair open Pink wire between ATC control head 12-pin connector and junction block. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
3. Using a DVOM, measure voltage between ground and ATC control head 12-pin connector terminal No. 11 (Yellow/Dark Green wire). If voltage is less than 10.0 volts, go to next step. If voltage is more than 10.0 volts, repair short to battery voltage in Yellow/Dark Green wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
4. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Black 24-pin connector (C2). Ensure connector terminals are clean and tight. Repair as necessary.
5. Using a DVOM, measure resistance in Yellow/Dark Green wire between ATC control head Black 12-pin connector terminal No. 11 and BCM connector C2 terminal No. 12. If resistance is less than 5.0 ohms, go to next step. If resistance is more than 5.0 ohms, repair open in Yellow/Dark Green wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
6. Ensure ignition is off. Reconnect ATC control head connector. Connect a jumper wire between ground and BCM connector C2 terminal No. 5 (Yellow/Dark Green wire). Turn ignition on (engine off). Visually inspect aspirator fan motor. If aspirator fan motor operates, replace BCM. If aspirator motor does not operate, replace aspirator motor. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .

TEST 8D: ATC ASPIRATOR MOTOR CONTINUES TO OPERATE

Note. Perform TEST 8A: ATC IN-VEHICLE TEMPERATURE THERMISTOR FAILURE before proceeding with this test. Use this test when aspirator fan motor continues to operate when ignition is off and doors are closed.

Note. BCM controls courtesy lights, which should fade to off within 5 seconds of last vehicle door being closed and ignition off.

1. If courtesy lights operate properly from left front door, go to next step. If courtesy lights do not operate properly from left front door, go to appropriate BODY CONTROL COMPUTER article in ACCESSORIES & EQUIPMENT.
2. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Gray 14-pin connector (C1). Ensure connector terminals are clean and tight. Repair as necessary.
3. If aspirator fan motor stops operating when BCM connector C1 is disconnected, replace BCM. If aspirator fan motor does not stop operating when BCM connector is disconnected, repair short to ground in Yellow/Dark Green wire between aspirator fan motor and BCM Black 24-pin connector C2 terminal No. 5.

TEST 9A: MODE DOOR FEEDBACK/STALL TEST FAILURE

Note. Perform TEST 1B: IDENTIFYING ATC SYSTEM BCM DIAGNOSTIC TROUBLE CODES before proceeding with this test. DTC 24 will set when BCM detects a loss of signal on mode door and/or blend air door feedback inputs. DTC 33 will set when BCM cannot detect end of travel for one or more ATC system doors.

1. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Black 24-pin connector C2. Using a DVOM, backprobe BCM connector C2 terminal No. 15 (Pink/Dark Blue wire) and reconnect connector.
2. Turn ignition on (engine off) and measure voltage. If voltage is 4.0-10.0 volts, go to step 6. If voltage is less than 4.0 volts, go to next step. If voltage is more than 10.0 volts, repair short to battery voltage in Pink/Dark Blue wire between BCM and actuator. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
3. Turn ignition off. Disconnect BCM connector C2. Ensure connector terminals are clean and tight. Repair as necessary. Using a DVOM, measure resistance between ground and BCM connector C2 terminal No. 15 (Pink/Dark Blue wire). If resistance is more than 5.0 ohms, go to next step. If resistance is less than 5.0 ohms, repair short to ground in Pink/Dark Blue wire between BCM and actuator. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
4. Using a DVOM, measure resistance between BCM Gray 14-pin connector C1 terminal No. 8 (Dark Blue/Gray wire) and BCM connector C2 terminal No. 15 (Pink/Dark Blue wire). If resistance is less than 2000.0 ohms, go to next step. If resistance is more than 2000.0 ohms, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
5. Disconnect mode door actuator connector. Ensure connector terminals are clean and tight. see scheme 2 Repair as necessary. Using a DVOM, measure resistance between BCM connector C1 terminal No. 8 (Dark Blue/Gray wire) and BCM connector C2 terminal No. 15 (Pink/Dark Blue wire). If resistance is less than 2000.0 ohms, replace blend air door actuator. If resistance is more than 2000.0 ohms, replace mode door actuator. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
6. Using a DVOM, backprobe A/C-heater assembly plenum 16-pin connector terminal No. 6 (Pink/Dark Blue wire). If voltage is more than 4.0 volts, go to next step. If voltage is less than 4.0 volts, repair open in Pink/Dark Blue wire between plenum and BCM connector C2 terminal No. 15. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
7. Turn ignition off and disconnect BCM connector C2. Using a DVOM, backprobe BCM connector C2 terminal No. 9 (Yellow/White wire). Reconnect BCM connector C2 and turn ignition on. If voltage is less than 0.3 volt, go to next step. If voltage is 0.3-10.0 volts, go to step 11. If voltage is more than 10.0 volts, repair short to battery voltage in Yellow/White wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
8. Using a DVOM, backprobe A/C-heater assembly plenum 16-pin connector terminal No. 11 (Yellow/White wire). If voltage is less than 0.3 volt, go to next step. If voltage is 0.3 volt or more, repair open in Yellow/White wire between BCM connector and plenum connector. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
9. Turn ignition off. Disconnect A/C-heater assembly plenum 16-pin connector and BCM connector C2. Ensure connector terminals are clean and tight. Repair as necessary. Using a DVOM, measure resistance between ground and BCM connector C2 terminal No. 9 (Yellow/White wire). If resistance is more than 5.0 ohms, go to next step. If resistance is less than 5.0 ohms, repair short to ground in Yellow/White wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
10. Check mode door travel. Remove mode door actuator and rotate door shaft in both directions. Ensure door moves smoothly and stops at both ends of its travel. Repair or replace linkage and/or mode door as necessary. If mode door travel is okay, replace mode door actuator. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
11. Turn ignition off. Close all vehicle doors. Ensure courtesy lights are off and wait one minute. Using a DVOM, backprobe A/C-heater assembly plenum 16-pin connector terminal No. 5 (Dark Blue/Gray wire). If resistance is less than 60.0 ohms, go to next step. If resistance is more than 60.0 ohms, go to «TEST 9B: SENSOR GROUND CIRCUIT»(ref-211-S35615009662000030800000).
12. Disconnect BCM Gray 14-pin connector (C1). Using a DVOM, backprobe BCM connector C1 terminal No. 10 (Brown/White wire). Reconnect all disconnected BCM connectors. Turn ignition on (engine off). Turn recirculation button off and panel button on. Turn recirculation button on while observing voltage change. If voltage increases to more than 10.0 volts, go to next step. If voltage does not increase to more than 10.0 volts, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
13. Using scan tool, clear all DTCs. Using a DVOM, backprobe A/C-heater assembly plenum 16-pin connector terminal No. 2 (Dark Green/Yellow wire). Push ATC control head panel button, then front defrost button, and then bi-level button. Observe voltage change. If voltage increases to more than 10.0 volts, go to step 15. If voltage does not increase to more than 10.0 volts, go to next step.
14. Turn ignition off and disconnect BCM Gray 14-pin connector (C1). Using a DVOM, backprobe BCM connector C1 terminal No. 9 (Light Green/Black wire) and reconnect BCM connector C1. Turn ignition on (engine off) and observe voltmeter. Push ATC control head panel button, then front defrost button, and then bi-level button. Observe voltage change. If voltage increases to more than 10.0 volts, repair open in Dark Green/Yellow wire between BCM and A/C-heater assembly plenum connector. If voltage does not increase to more than 10.0 volts, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
15. Turn ignition off. Disconnect BCM Gray 14-pin connector (C1). Disconnect A/C-heater assembly plenum 16-pin connector. Ensure connector terminals are clean and tight. Using a DVOM, measure resistance in Brown/White wire between BCM connector C1 terminal No. 10 and plenum 16-pin connector terminal No. 1. If resistance is less than 5.0 ohms, go to next step. If resistance is more than 5.0 ohms, repair open in Brown/White wire between BCM connector C1 and plenum connector. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
16. Check mode air door travel. Remove mode air door actuator, and rotate door shaft in both directions. Ensure door moves smoothly and stops at both ends of its travel. Repair or replace linkage and/or mode door as necessary. If mode door travel is okay, replace door actuator. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).

TEST 9B: SENSOR GROUND CIRCUIT

Note. Perform TEST 9A: MODE DOOR FEEDBACK/STALL TEST FAILURE before proceeding with this test.

1. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Gray 14-pin connector (C1). Ensure connector terminals are clean and tight. Repair as necessary.
2. Using a DVOM, backprobe BCM connector C1 terminal No. 8 (Dark Blue/Gray wire). Observe ohmmeter and reconnect BCM connector. If resistance is more than 60 ohms, go to next step. If resistance is less than 60 ohms, repair open in Dark Blue/Gray wire between BCM connector C1 and A/C-heater assembly plenum 16-pin connector terminal No. 5. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
3. Ensure ignition is off. Remove BCM from junction block. Ensure junction block 20-pin connector terminals are clean and not damaged. Repair or replace junction block as necessary. If connector terminals are okay, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .

TEST 10A: MODE DOOR OUTPUT SHORTED TO GROUND

Note. Perform TEST 1B: IDENTIFYING ATC SYSTEM BCM DIAGNOSTIC TROUBLE CODES before proceeding with this test. DTC 40 will set if BCM detects mode door drive output shorted to ground.

1. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Gray 14-pin connector (C1). Ensure connector terminals are clean and tight. Repair as necessary.
2. Turn ignition off. Close all doors and ensure courtesy lights are off. Using a DVOM, measure resistance between ground and BCM connector C1 terminal No. 9 (Dark Green/Yellow wire). If resistance is less than 5.0 ohms, repair short to ground in Dark Green/Yellow wire. If resistance is more than 5.0 ohms, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .

TEST 11A: RECIRCULATION DOOR OUTPUT SHORTED TO GROUND

Note. Perform TEST 1B: IDENTIFYING ATC SYSTEM BCM DIAGNOSTIC TROUBLE CODES before proceeding with this test. DTC 42 will set if BCM detects recirculated air door drive output shorted to ground.

1. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Gray 14-pin connector (C1). Ensure connector terminals are clean and tight. Repair as necessary.
2. Turn ignition off. Close all doors and ensure courtesy lights are off. Using a DVOM, measure resistance between ground and BCM connector C1 terminal No. 2 (Gray/Dark Blue wire). If resistance is less than 5.0 ohms, repair short to ground in Gray/Dark Blue wire. If resistance is more than 5.0 ohms, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .

TEST 12A: RECIRCULATION DOOR ACTUATOR STALL TEST FAILURE

Note. Perform TEST 1B: IDENTIFYING ATC SYSTEM BCM DIAGNOSTIC TROUBLE CODES before proceeding with this test. DTC 31 will set if BCM cannot detect recirculated air door end of travel during calibration.

1. Turn ignition on and engine off. Locate A/C-heater assembly plenum 16-pin connector, but do not disconnect connector. Using a DVOM, backprobe plenum 16-pin connector terminal No. 6 (Pink/Dark Blue wire). If voltage is 4.5-10.0 volts, go to next step. If voltage is less than 4.5 volts, repair open in Pink/Dark Blue wire. If voltage is more than 10.0 volts, repair short to battery voltage in Pink/Dark Blue wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
2. Disconnect recirculation door actuator 5-pin connector. Ensure connector terminals are clean and not damaged. Repair as necessary. Using a DVOM, measure voltage between ground and actuator 5-pin connector terminal No. 5 (Brown/White wire). On ATC control head, turn panel button on and recirculation button off. Turn recirculation button on and observe voltage changes. If voltage changes to more than 10.0 volts, go to next step. If voltage does not increase to more than 10.0 volts, go to «TEST 12B: RECIRCULATION DOOR STALL TEST FAILURE OR INOPERATIVE»(ref-211-S27789151212000030800000) .
3. Using a DVOM, measure voltage between actuator 5-pin connector terminal No. 1 (Gray/Dark Blue wire). Turn recirculation button off and observe voltage changes. If voltage changes to more than 10.0 volts, go to next step. If voltage does not increase to more than 10.0 volts, go to «TEST 12C: RECIRCULATION DOOR STALL TEST FAILURE OR INOPERATIVE»(ref-211-S33788252022000030800000) .
4. Turn ignition off. Using a DVOM, backprobe between A/C-heater assembly plenum 16-pin connector terminals No. 1 (Brown/White wire) and No. 2 (Dark Green/Yellow wire) and measure resistance. If resistance is 15.0-35.0 ohms, go to next step. If resistance is not 15.0-35.0 ohms, go to «TEST 19A: INOPERATIVE MODE DOOR»(ref-211-S07878435822000030800000) .
5. Using a DVOM, backprobe between A/C-heater assembly plenum 16-pin connector terminals No. 1 (Brown/White wire) and No. 3 (Dark Blue/Red wire) and measure resistance. If resistance is 15.0-35.0 ohms, go to next step. If resistance is not 15.0-35.0 ohms, go to «TEST 15A: INOPERATIVE TEMPERATURE/BLEND AIR DOOR»(ref-211-S14558780642000030800000) .
6. Reconnect recirculation door actuator 5-pin connector. Using a DVOM, backprobe between A/C-heater assembly plenum 16-pin connector terminals No. 1 (Brown/White wire) and No. 4 (Gray/Dark Blue wire) and measure resistance. If resistance is 15.0-35.0 ohms, go to next step. If resistance is not 15.0-35.0 ohms, replace recirculation door actuator. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
7. Check recirculation air door travel. Remove recirculation air door actuator and rotate door shaft in both directions. Ensure door moves smoothly and stops at both ends of its travel. Repair or replace linkage and/or door as necessary. If recirculation door travel is okay, replace door actuator. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .

TEST 12B: RECIRCULATION DOOR ACTUATOR STALL TEST FAILURE

Note. Perform TEST 12A: RECIRCULATION DOOR ACTUATOR STALL TEST FAILURE before proceeding with this test.

1. Using scan tool, clear all DTCs. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Gray 14-pin connector (C1). Using a DVOM, backprobe BCM connector C1 terminal No. 10 (Brown/White wire) and reconnect BCM connector.
2. Turn ignition on and engine off. Turn recirculation button off and then on, and observe voltage change. If voltage changes to more than 10.0 volts, repair open in Brown/White wire between BCM connector C1 and A/C-heater assembly 16-pin plenum connector terminal No. 1. If voltage does not increase to more than 10.0 volts, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .

TEST 12C: RECIRCULATION DOOR ACTUATOR STALL TEST FAILURE

Note. Perform TEST 12A: RECIRCULATION DOOR ACTUATOR STALL TEST FAILURE before proceeding with this test.

1. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Gray 14-pin connector (C1). Using a DVOM, backprobe BCM connector C1 terminal No. 2 (Gray/Dark Blue wire) and reconnect connector.
2. Turn ignition on and engine off. Turn recirculation button on and then off, and observe voltage change. If voltage changes to more than 10.0 volts, repair open in Gray/Dark Blue wire between BCM connector C1 and A/C-heater assembly 16-pin plenum connector terminal No. 4. If voltage does not increase to more than 10.0 volts, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .

TEST 13A: ATC IN-VEHICLE SUN LOAD SENSOR FAILURE

Note. Perform TEST 1B: IDENTIFYING ATC SYSTEM BCM DIAGNOSTIC TROUBLE CODES before proceeding with this test. DTC 27 will set if BCM detects an abnormally low voltage (less than 0.313 volt) on sun load sensor input.

1. Using scan tool, read SUN SENSOR voltage. If voltage is less than 0.2 volt, go to next step. If voltage is more than 0.2 volt, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
2. Locate sun load sensor at top center of dashboard, near windshield. Disconnect sensor connector and ensure connector terminals are clean and tight. Repair as necessary. Using scan tool, read SUN LOAD sensor voltage. If voltage is less than 0.2 volt, go to next step. If voltage is more than 0.2 volt, replace sun load sensor. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
3. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Black 24-pin connector (C2). Ensure connector terminals are clean and tight. Repair as necessary.
4. Using a DVOM, measure resistance between ground and BCM connector C2 terminal No. 10 (Dark Blue wire). If resistance is less than 60.0 ohms, repair short to ground in Dark Blue wire between BCM connector C2 and sun load sensor. If resistance is more than 60.0 ohms, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .

TEST 14A: COMPRESSOR CLUTCH CIRCUIT

Note. Perform TEST 1A: IDENTIFYING ATC SYSTEM PROBLEMS before proceeding with this test.

1. Momentarily press ATC control head A/C ON button. If a beep is heard from BCM when button is pressed, go to next step. If a beep is not heard from BCM, replace ATC control head. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
2. Start engine and allow to idle. Turn A/C on. Using scan tool, select CLIMATE CONTROL, SYSTEM TESTS, and A/C ON TO BCM. Look for an ON or OFF message and disregard NR message if displayed. If scan tool displays A/C BCM: ON, go to next step. If scan tool does not display A/C BCM: ON, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
3. If scan tool displays PCM: ON, go to next step. If scan tool does not display PCM: ON, replace PCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
4. Using scan tool select ENGINE and then READ DTCS. If scan tool does not display any PCM DTCs, go to next step. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE if any of the following A/C-heater system related PCM DTCs are displayed: ECT SENSOR VOLTAGE TOO LOW ECT SENSOR VOLTAGE TOO HIGH A/C PRESSURE SENSOR VOLTAGE TOO HIGH A/C PRESSURE SENSOR VOLTAGE TOO LOW LOW SPEED FAN CONTROL RELAY CIRCUIT HIGH SPEED FAN CONTROL RELAY CIRCUIT A/C CLUTCH RELAY CIRCUIT ENGINE IS COLD TOO LONG
5. Turn engine off and ignition on. Locate A/C clutch connector on top of compressor. Disconnect A/C clutch connector. Ensure connector is clean and tight. Repair as necessary.
6. Connect a voltmeter between ground and A/C clutch connector terminal No. 1 (Dark Blue/Black wire). Using scan tool, actuate A/C clutch relay and measure voltage. If voltage does not increase to more than 10.0 volts, go to next step. If voltage increases to more than 10.0 volts, check A/C clutch ground circuit. If ground circuit is okay, replace A/C clutch. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
7. Remove A/C clutch relay, located at position No. 10 in Power Distribution Center (PDC). Using a DVOM, measure voltage between ground and PDC A/C clutch relay socket terminal "B" (Red/Brown wire). If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair open Red/Brown wire between PDC A/C clutch relay and fuse "B" (30-amp). Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
8. Connect a jumper wire between ground and A/C clutch connector terminal No. 1 (Dark Blue/Black wire). Using a DVOM, measure resistance between ground and PDC A/C clutch relay socket terminal "D". If resistance is less than 5.0 ohms, replace A/C clutch relay. If resistance is more than 5.0 ohms, repair open in Dark Blue/Black wire.

TEST 15A: INOPERATIVE TEMPERATURE/BLEND AIR DOOR

Note. Perform TEST 1A: IDENTIFYING ATC SYSTEM PROBLEMS before proceeding with this test.

1. Using scan tool, select CLIMATE CONTROL and actuate temperature/blend air door from hot position to cold position. Using scan tool voltmeter, observe voltage change as temperature/blend air door moves from hot position to cold position. If voltage changes from approximately 0.3 volt to 4.0 volts, go to «TEST 19A: INOPERATIVE MODE DOOR»(ref-211-S07878435822000030800000). If voltage does not change as specified, go to next step.
2. Stop actuation test. Calibrate ATC doors. See «IN-VEHICLE CALIBRATION & DTC CHECK»(ref-211-S37766020892000030800000) under ADJUSTMENTS. Using a DVOM, backprobe between ground and A/C-heater assembly plenum 16-pin connector terminal No. 3 (Dark Blue/Red wire). Observe voltage and change temperature from cold to hot. If voltage increases to more than 9.0 volts, go to next step. If voltage does not increase to more than 9.0 volts, go to step 4.
3. Check blend air door travel. Remove blend air door actuator, and rotate door shaft in both directions. Ensure door moves smoothly and stops at both ends of its travel. Repair as necessary. If blend air door travel is okay, replace door actuator. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
4. Disconnect blend air door actuator connector. This will cause BCM to set a DTC that will have to be cleared later. Ensure actuator connector is clean and tight. Repair as necessary.
5. Ensure voltmeter is still connected to A/C-heater assembly plenum connector terminal No. 3. Press A/C OFF button and observe voltage. Turn ignition off, then on. Press A/C ON button and change temperature from cold to hot. If voltage does not increase to more than 9.0 volts, go to next step. If voltage increases to more than 9.0 volts, go to step 3.
6. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Gray 14-pin connector (C1). Ensure connector terminals are clean and tight. Repair as necessary.
7. Using a DVOM, backprobe BCM connector C1 terminal No. 3 (Dark Blue/Red wire). Reconnect BCM connector C1. Observe voltage and change temperature from cold to hot. If voltage does not increase to more than 9.0 volts, go to next step. If voltage increases to more than 9.0 volts, go to step 3.
8. Disconnect A/C-heater assembly plenum 16-pin connector. Ensure connector terminals are clean and tight. Repair as necessary. see scheme 2 Turn ignition off. Disconnect BCM Gray 14-pin connector (C1). Ensure connector terminals are clean and tight. Repair as necessary.
9. Using a DVOM, measure resistance in Brown/White wire between A/C-heater assembly plenum 16-pin connector terminal No. 1 and BCM connector C1 terminal No. 10. If resistance is more than 5.0 ohms, repair open Brown/White wire. If resistance is less than 5.0 ohms, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).

TEST 16A: INOPERATIVE BLOWER MOTOR

Note. Perform TEST 1A: IDENTIFYING ATC SYSTEM PROBLEMS before proceeding with this test.

1. Remove and inspect fuse No. 23 (30-amp), located in junction block. (Scheme 3)and (Scheme 4). If fuse is open, go to next step. If fuse is okay, go to step 4.
2. Turn ignition off. Locate blower motor power module, on lower right side of A/C-heater assembly. see scheme 2 Disconnect blower motor power module 4-pin connector. Ensure connector terminals are clean and tight. Repair as necessary.
3. Using a DVOM, measure resistance between ground and power module 4-pin connector terminal No. 4 (Dark Green wire). If resistance is more than 5.0 ohms, go to next step. If resistance is less than 5.0 ohms, repair short to ground in Dark Green wire and replace fuse No. 23 (30-amp). Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
4. Disconnect blower motor 2-pin connector. Ensure connector terminals are clean and tight. Repair as necessary. Replace fuse No. 23 (30-amp), and go to «TEST 16B: INOPERATIVE BLOWER MOTOR»(ref-211-S01933378712000030800000).
5. Reinstall fuse No. 23 (30-amp). Using a DVOM, measure voltage between ground and ignition switch side of fuse No. 23 terminal (Black/Orange wire). If voltage is more than 10.0 volts, go to next step. If voltage is less than 10.0 volts, repair open in Black/Orange wire between ignition switch and fuse No. 23. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
6. Turn ignition off. Locate blower motor power module, on lower right side of A/C-heater assembly. see scheme 2 Disconnect blower motor power module 4-pin connector. Ensure connector terminals are clean and tight. Repair as necessary.
7. Using a DVOM, measure voltage between ground and blower motor power module 4-pin connector terminal No. 4 (Dark Green wire). If voltage is more than 10.0 volts, go to next step. If voltage is less than 10.0 volts, repair open in Dark Green wire between fuse No. 23 (30-amp) and power module connector terminal No. 4. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
8. Turn ignition off. Using a DVOM, measure resistance between ground and blower motor power module 4-pin connector terminal No. 2 (Black wire). If resistance is less than 5.0 ohms, go to next step. If resistance is more than 5.0 ohms, repair open in Black wire between power module 4-pin connector and ground. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
9. Using a DVOM, measure resistance between ground and blower motor power module 4-pin connector terminal No. 3 (Red/Light Green wire). If resistance is more than 5.0 ohms, go to next step. If resistance is less than 5.0 ohms, repair short to ground in Red/Light Green wire between power module and BCM Black 24-pin connector C2 terminal No. 6. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
10. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. (Scheme 3) Turn ignition off. Disconnect BCM Black 24-pin connector (C2). Ensure connector terminals are clean and tight. Repair as necessary.
11. Connect blower motor power module 4-pin connector. Turn ignition on and engine off. If blower motor does not operate at full speed, go to next step. If blower motor operates at full speed, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
12. Turn ignition off. Disconnect blower motor 2-pin connector. Ensure connector terminals are clean and tight. Connect a jumper wire between blower motor connector terminal No. 2 (Black wire) and blower motor power module 4-pin connector terminal No. 2 (Black wire).
13. Connect a second jumper wire between power module connector terminal No. 4 (Dark Green wire) and blower motor connector terminal No. 1 (Dark Green wire). Turn ignition on for 10 seconds and then off. If blower operates at high speed without blowing fuse No. 23 (30-amp), replace blower motor power module. If blower does not operate at high speed without blowing fuse No. 23, replace blower motor. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).

Scheme 4

TEST 16B: INOPERATIVE BLOWER MOTOR

Note. Perform TEST 16A: INOPERATIVE BLOWER MOTOR before proceeding with this test.

1. Connect a jumper wire between blower motor connector terminal No. 2 (Black wire) and blower motor power module connector terminal No. 2 (Black wire). see scheme 2 Connect a second jumper wire between power module connector terminal No. 4 (Dark Green wire) and blower motor connector terminal No. 1 (Dark Green wire).
2. Turn ignition on for 10 seconds and then off. If blower motor does not operate at high speed without blowing fuse No. 23 (30-amp), go to next step. If blower operates at high speed without blowing fuse No. 23, replace blower motor power module. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
3. Remove jumper wires. Remove blower motor. Inspect blower motor wheel for binding or damage. Repair as necessary and replace fuse No. 23 (30-amp). If no damage or binding exists, replace blower motor and fuse No. 23. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).

TEST 17A: INCORRECT BLOWER MOTOR SPEEDS

Note. Perform TEST 1A: IDENTIFYING ATC SYSTEM PROBLEMS before proceeding with this test.

1. Turn ignition on and operate blower motor. If blower motor is stuck on high speed, go to next step. If blower motor is not stuck on high speed, replace ATC control head. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
2. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. (Scheme 3) Turn ignition off. Remove BCM from junction block. Ensure 20-pin internal connector terminals are clean and tight. (Scheme 5) Repair as necessary.
3. Using a DVOM, measure resistance between ground and junction block 20-pin internal connector terminal No. 20. If resistance is less than 5.0 ohms, go to next step. If resistance is more than 5.0 ohms, repair open in junction block ground circuit. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
4. Using a DVOM, measure resistance between ground and junction block 20-pin internal connector terminal No. 1. If resistance is less than 5.0 ohms, go to next step. If resistance is more than 5.0 ohms, repair open in junction block ground circuit. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
5. Disconnect blower motor power module 4-pin connector. Ensure connector terminals are clean and tight. Repair as necessary. Turn ignition on and engine off. Using a DVOM, measure voltage between ground and power module 4-pin connector terminal No. 4 (Dark Green wire). If voltage is less than one volt, go to next step. If voltage is more than one volt, repair short to battery voltage in Dark Green wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
6. Turn ignition off. Reconnect blower motor power module 4-pin connector. Connect a jumper wire between ground and BCM Black 24-pin connector C2 terminal No. 6 (Red/Light Green wire). Turn ignition on. If blower motor still operates at high speed, go to next step. If blower does not operate at high speed, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
7. Turn ignition off and remove jumper wire. Disconnect blower motor power module 4-pin connector. Using a DVOM, measure resistance of Red/Light Green wire between BCM connector C2 terminal No. 6 and power module 4-pin connector terminal No. 3. If resistance is less than 5.0 ohms, go to next step. If resistance is more than 5.0 ohms, repair open in Red/Light Green wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
8. Using a DVOM, measure resistance between ground and power module 4-pin connector terminal No. 2 (Black wire). If resistance is more than 5.0 ohms, repair open in Black wire. If resistance is less than 5.0 ohms, replace blower motor power module. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).

Scheme 5

TEST 18A: ATC CONTROL HEAD ILLUMINATION

Note. Perform TEST 1A: IDENTIFYING ATC SYSTEM PROBLEMS before proceeding with this test. If instrument panel lights do not operate properly, see ILLUMINATION/INTERIOR LIGHTS article in ACCESSORIES & EQUIPMENT.

1. If ATC control head illumination problem is with background lights, go to next step. If ATC control head illumination problem is with letters, numbers and LEDs, replace ATC control head. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
2. Turn ignition off. Disconnect ATC control head 12-pin connector. Ensure connector terminals are clean and tight. Repair as necessary.
3. Turn parking lights on. Using a DVOM, measure voltage between ground and ATC control head Black 12-pin connector terminal No. 4 (Orange wire). Observe voltage change while rotating dimmer switch thumb wheel. If voltage changes from less than 3.5 volts to more than 9.0 volts, replace ATC control head. If voltage does not change from less than 3.5 volts to more than 9.0 volts, repair open in Orange wire. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .

TEST 19A: INOPERATIVE MODE DOOR

Note. Perform TEST 1A: IDENTIFYING ATC SYSTEM PROBLEMS before proceeding with this test.

1. Connect scan tool and select CLIMATE CONTROL and MISCELLANEOUS. Using scan tool, actuate ATC mode door between panel and defrost positions while observing voltage change on scan tool. If voltage on scan tool changes between approximately 0.3 volt and 4.0 volts, system is operating properly at this time. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000). If voltage does not change between 0.3 volt and 4.0 volts, go to next step.
2. Stop actuation test. Calibrate ATC doors. See «IN-VEHICLE CALIBRATION & DTC CHECK»(ref-211-S37766020892000030800000) under ADJUSTMENTS. Using a DVOM, backprobe A/C-heater assembly plenum 16-pin connector terminal No. 2 (Dark Green/Yellow wire). While observing voltmeter, activate ATC control head panel button, then defrost button, and then bi-level button. If voltage increases to more than 9.0 volts, go to next step. If voltage does not increase to more than 9.0 volts, go to step 4.
3. Check mode door travel. Remove mode door actuator, and rotate door shaft in both directions. Ensure door moves smoothly and stops at both ends of its travel. Repair as necessary. If mode door travel is okay, replace door actuator. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
4. Disconnect mode door actuator connector. This will cause a DTC to set which will have to be cleared later. Ensure actuator connector terminals are clean and tight. Repair as necessary.
5. Ensure voltmeter is still connected to plenum 16-pin connector terminal No. 2. Observe voltmeter and turn A/C off. Turn ignition off and then on. Turn A/C on. Activate panel button, then defrost button, and then bi-level button. If voltage does not increase to more than 9.0 volts, go to next step. If voltage increases to more than 9.0 volts, go to step 3.
6. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. (Scheme 3) Turn ignition off. Disconnect BCM Gray 14-pin connector (C1). Ensure connector terminals are clean and tight. Repair as necessary.
7. Using a DVOM, backprobe BCM connector C1 terminal No. 9 (Dark Green/Yellow wire) and reconnect BCM connector C1. Observe voltage while activating panel button, defrost button, and then bi-level button. If voltage does not increase to more than 10.0 volts, go to next step. If voltage increases to more than 10.0 volts, repair open in Dark Green/Yellow wire between BCM connector C1 and A/C-heater assembly plenum 16-pin connector. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).
8. Turn ignition off. Disconnect A/C-heater assembly plenum 16-pin connector. Disconnect BCM Gray 14-pin connector (C1). Ensure terminals of both connectors are clean and tight. Repair as necessary.
9. Using a DVOM, measure resistance of Brown/White wire between BCM connector C1 terminal No. 10 and plenum 16-pin connector terminal No. 1. If resistance is more than 5.0 ohms, repair open in Brown/White wire. If resistance is less than 5.0 ohms, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000).

TEST 21A: INCORRECT TEMPERATURE CONTROL IN SUN OR SHADE

Note. Perform TEST 1A: IDENTIFYING ATC SYSTEM PROBLEMS before proceeding with this test.

1. Disconnect sun load sensor 4-pin connector, located above center of instrument panel. Ensure connector terminals are clean and tight. Using scan tool, select BODY COMPUTER, SENSORS and read SUN SENSOR voltage. If scan tool does not display SUN SENSOR: BELOW 4.8 V, go to next step. If scan tool displays SUN SENSOR: BELOW 4.8 V, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
2. Connect a jumper wire between sensor 4-pin connector terminals No. 3 (Dark Blue/Gray wire) and No. 4 (Dark Blue wire). Using scan tool, read SUN SENSOR voltage. If scan tool does not display SUN SENSOR: BELOW 0.2 V, go to next step. If scan tool displays SUN SENSOR: BELOW 0.2 V, replace sun load sensor. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .
3. Disconnect jumper wire from sun load sensor 4-pin connector terminal No. 3. Connect jumper wire between ground and sensor 4-pin connector terminal No. 4 (Dark Blue wire). If scan tool does not display SUN SENSOR: BELOW 0.2 V, go to next step. If scan tool displays SUN SENSOR: BELOW 0.2 V, repair open Dark Blue/Gray wire between sensor 4-pin connector and ground.
4. Remove jumper wire. Locate Body Control Module (BCM), attached to junction block, at left end of instrument panel. Turn ignition off. Disconnect BCM Black 24-pin connector (C2). Ensure connector terminals are clean and tight. Repair as necessary.
5. Using a DVOM, measure resistance of Dark Blue wire between BCM connector C2 terminal No. 10 and sun load sensor 4-pin connector terminal No. 4. If resistance is more than 5.0 ohms, repair open in Dark Blue wire between BCM and sun load sensor connector. If resistance is less than 5.0 ohms, replace BCM. Perform «VERIFICATION TEST»(ref-211-S02209447162000030800000) .

VERIFICATION TEST

1. Reconnect all previously disconnected components and wiring. If Body Control Module (BCM) has not been replaced, go to next step. If BCM has been replaced, use DRB (scan tool) to program all Remote Keyless Entry (RKE) transmitters, recalibrate ATC system doors, and program other options as necessary.
2. If ATC system has been repaired or battery has been disconnected, ATC door actuators must be calibrated. Start engine and use scan tool to calibrate door actuators. DO NOT allow vehicle to move during door actuator calibration. Turn engine off and go to next step.
3. Turn ignition on. Using scan tool, erase Diagnostic Trouble Codes (DTCs). Turn ignition off and wait at least 5 seconds. Turn ignition on (engine off) and fully operate repaired system to verify correct operation. If system operates properly, go to next step. If system does not operate properly, go to «TEST 1A: IDENTIFYING ATC SYSTEM PROBLEMS»(ref-211-S09989412222000030800000) .
4. If A/C-heater system operates properly, use scan tool to check for other BCM DTCs. If any BCM DTCs are present, go to «TEST 1B: IDENTIFYING ATC SYSTEM BCM DIAGNOSTIC TROUBLE CODES»(ref-211-S17498362982000030800000) . If no BCM DTCs are present and original DTC cannot be duplicated, repair is complete.