Automatic A/c-Heater Systems: Other Mazda Millenia I рестайлинг

CLIMATE CONTROL UNIT

Based on control switch settings, climate control unit sends signals to A/C amplifier. A/C amplifier sends signals back to climate control unit and display window to show selected control settings for blower speed, airflow mode, temperature setting, etc. (Scheme 22) A/C switch determines whether A/C is in normal (A/C) mode or economy (ECON) mode. Selecting temperature setting and then depressing AUTO places system in automatic mode.

During automatic operation, all A/C controls are operated by climate control unit and A/C amplifier. Automatic operation can be verified by illuminated AUTO indicator on control unit. Manual control of A/C system is also possible. To cancel automatic function, press appropriate climate control unit switch.

Scheme 22

A/C COMPRESSOR CLUTCH CONTROL

A/C amplifier determines system operating conditions based on voltage signals received from various sensors. A/C amplifier then sends information to Engine Control Module (ECM) to control grounding of A/C relay coil winding circuit, providing power to A/C compressor clutch. If high-side refrigerant pressure is less than 25-32 psi (1.7-2.3 kg/cm 2 ) or more than 430-480 psi (30-34 kg/cm 2 ), pressure switch interrupts power to A/C compressor clutch.

BLOWER MOTOR CONTROL

A/C amplifier grounds blower relay coil winding circuit to energize relay, providing power to blower motor. Depending on blower speed setting, blower motor is grounded through power transistor (MOS FET, similar to blower resistor).

Air Intake (Fresh/Recirculated Air) Actuator

Air intake actuator controls position of fresh/recirculated air door in blower case. Door position determines whether fresh air or recirculated air enters blower case.

Air Mix Actuator

Air mix actuator controls position of air mix doors in heater case. Position of doors determines amount of airflow through heater core.

Airflow Mode Actuator

Airflow mode actuator controls position of airflow mode doors in heater case. Position of doors determines airflow mode (vent, bi-level, heat, heat/defrost and defrost).

SENSORS

A/C amplifier uses voltage signals from various sensors to determine system operating conditions. Solar radiation sensor is a photo sensor which measures intensity of sunlight. (Scheme 23)- (Scheme 24). All other sensors contain a thermistor that changes value according to surrounding temperature.

Sensors monitor sunlight load, ambient temperature, evaporator temperature, passenger compartment temperature and water temperature of engine coolant at heater core.

Scheme 23

Scheme 24

2.3L Engine

1. Remove compressor from vehicle. See «COMPRESSOR»(ref-98829-S18727860012001052600000) under REMOVAL & INSTALLATION. Set compressor end down with clutch facing upward. Affix a dial indicator with stand next to compressor with measuring tip touching compressor clutch outside edge.
2. Using a jumper wire, connect fused positive battery voltage to compressor clutch harness connector. Connect negative battery voltage to compressor body. Clutch should activate. Compare dial indicator readings. Clearance should be .016-.023" (.4-.6 mm).
3. If clearance is not as specified, remove clutch pressure plate and replace shims as necessary to obtain specified clearance. Reinstall pressure plate and retest. Repeat as necessary.

2.5L Engine

Using a feeler gauge, check compressor clutch clearance around entire circumference. Clearance should be .016-.023" (.4-.6 mm). If clearance is not as specified, remove clutch pressure plate and replace shims as necessary to obtain specified clearance. Reinstall pressure plate and retest. Repeat as necessary.

2000 Models

1. Turn ignition on. Press AUTO switch, windshield and rear window defrost switches, and air intake selector switch. If all LED indicators do not come on, go to next step. If any LED indicator does not come on, replace A/C amplifier.
2. If information display is dim or changes brightness, go to step 4. If information display is not dim or does not change brightness, go to next step.
3. Disconnect A/C amplifier 26-pin harness connector. Disconnect information display harness connector. Using DVOM, check continuity of Green/White wire between A/C amplifier harness connector and information display harness connector. If continuity exists, replace A/C amplifier or information display as necessary. If continuity does not exist, repair open or short circuit in Green/White wire between A/C amplifier harness connector and information display harness connector. See «WIRING DIAGRAMS»(ref-98829-S28086467362001052600000).
4. Turn ignition and light switches to ON position. Using DVOM, measure voltage at Red wire of A/C amplifier 22-pin harness connector. If battery voltage is present, go to next step. If battery voltage is not present, check continuity of Red wire between A/C amplifier 22-pin harness connector and panel light control module. Check wiring and operation of Tail Number Side (TNS) relay. See appropriate wiring diagram in ILLUMINATION/INTERIOR LIGHTS article. Repair as necessary.
5. Turn ignition to LOCK position. Turn light switch to OFF position. Disconnect A/C amplifier 20-pin harness connector. (Scheme 25) Using DVOM, check for continuity between 20-pin harness connector terminals 3J and 3L. see scheme 12 If continuity exists, reconnect A/C amplifier 20-pin connector and go to next step. If continuity does not exist, replace climate control unit. See «CLIMATE CONTROL UNIT»(ref-98829-S06174307582001052600000).
6. Using fused jumper wire, connect A/C amplifier 26-pin harness connector White/Violet wire to ground. Turn ignition and light switches to ON position. If climate control panel illumination lights do not turn on, replace A/C amplifier. If climate control panel illumination lights do turn on, check for open or short circuit between A/C amplifier and instrument panel light control switch. See «WIRING DIAGRAMS»(ref-98829-S28086467362001052600000). See appropriate wiring diagram in ILLUMINATION/INTERIOR LIGHTS article. Repair as necessary.

Scheme 25

2001 Models

1. Turn ignition on. Press AUTO switch, windshield and rear window defrost switches, and air intake selector switch. If all LED indicators do not come on, go to next step. If any LED indicator does not come on, replace A/C amplifier.
2. If information display is dim or changes brightness, go to step 4. If information display is not dim or does not change brightness, go to next step.
3. Disconnect A/C amplifier 8-pin harness connector. Disconnect information display harness connector. Using DVOM, check continuity of Green/White wire between A/C amplifier harness connector and information display harness connector. If continuity exists, replace A/C amplifier or information display as necessary. If continuity does not exist, repair open or short circuit in Green/White wire between A/C amplifier harness connector and information display harness connector. See «WIRING DIAGRAMS»(ref-98829-S28086467362001052600000).
4. Turn ignition and light switches to ON position. Using DVOM, check for battery voltage at Red wire of A/C amplifier 20-pin harness connector. If battery voltage is present, go to next step. If battery voltage is not present, check for open or short circuit between A/C amplifier 20-pin harness connector and Tail Number Side (TNS) relay. Check wiring and operation of TNS relay. See appropriate wiring diagram in ILLUMINATION/INTERIOR LIGHTS article. Repair as necessary.
5. Turn ignition to LOCK position. Turn light switch to OFF position. Disconnect climate control unit harness connector. Using DVOM, check for continuity between climate control harness connector terminals "J" and "L". (Scheme 26) If continuity exists, reconnect climate control unit harness connector and go to next step. If continuity does not exist, replace climate control unit. See «CLIMATE CONTROL UNIT»(ref-98829-S06174307582001052600000).
6. Using fused jumper wire, connect A/C amplifier 20-pin harness connector White/Violet wire to ground. Turn ignition and light switches to ON position. If climate control panel illumination lights do not turn on, replace A/C amplifier. If climate control panel illumination lights do turn on, check for open or short circuit between A/C amplifier and instrument panel light control switch. See «WIRING DIAGRAMS»(ref-98829-S28086467362001052600000). See appropriate wiring diagram in ILLUMINATION/INTERIOR LIGHTS article. Repair as necessary.

Scheme 26

1. Turn ignition switch to ON position. Turn AUTO, defrost, rear window defogger and recirculated/fresh air switches to ON position. If each indicator illuminates partially, go to next step. If each indicator does not illuminate partially, go to step 3.
2. Using DVOM, measure voltage at A/C amplifier 20-pin harness connector terminal related to malfunctioning indicator. (Scheme 25)and see scheme 12. For recirculated air indicator, probe terminal 3I. For fresh air indicator, probe terminal 3M. For defrost indicator, probe terminal 3G. For AUTO indicator, probe terminal 3E. For rear window defogger, probe terminal 3K. If voltage is zero volts at affected terminal, replace climate control unit. See «CLIMATE CONTROL UNIT»(ref-98829-S06174307582001052600000) under REMOVAL & INSTALLATION. If voltage is not zero volts at affected terminal, replace A/C amplifier. See «A/C AMPLIFIER»(ref-98829-S25462832762001052600000) under REMOVAL & INSTALLATION.
3. Using DVOM, check for battery voltage at A/C amplifier 20-pin harness connector terminal 3N. see scheme 12 If battery voltage is present, go to next step. If battery voltage is not present, replace A/C amplifier.
4. Using DVOM, measure voltage at A/C amplifier 20-pin harness connector terminal 3M. see scheme 12 If zero volts are present, replace climate control unit. If zero volts are not present, replace A/C amplifier.

1. Turn ignition switch to ON position. Turn AUTO, defrost, rear window defogger and recirculated/fresh air switches to ON position. If any or all switch lights illuminate, go to next step. If no switch lights illuminate, go to step 3.
2. Using DVOM, measure voltage at climate control unit harness connector terminal related to malfunctioning indicator. (Scheme 26) For recirculated air indicator, probe terminal "I". For fresh air indicator, probe terminal "M". For defrost indicator, probe terminal "G". For AUTO indicator, probe terminal "E". For rear window defogger, probe terminal "K". If voltage is zero volts at affected terminal, replace climate control unit. See «CLIMATE CONTROL UNIT»(ref-98829-S06174307582001052600000) under REMOVAL & INSTALLATION. If voltage is not zero volts at affected terminal, replace A/C amplifier. See «A/C AMPLIFIER»(ref-98829-S25462832762001052600000) under REMOVAL & INSTALLATION.
3. Using DVOM, check for battery voltage at climate control unit harness connector terminal "N". (Scheme 26) If battery voltage is present, go to next step. If battery voltage is not present, replace A/C amplifier.
4. Using DVOM, measure voltage at climate control unit harness connector terminal "M". (Scheme 26) If zero volts are present, replace climate control unit. If zero volts are not present, replace A/C amplifier.

1. Raise front of vehicle. Place gear selector lever in Neutral. Manually rotate both front wheels at the same time. Measure voltage at Green/Red wire terminal of A/C amplifier 26-pin harness connector. If voltmeter needle does not fluctuate between zero and 5 volts, go to next step. If voltmeter needle fluctuates between zero and 5 volts, replace A/C amplifier.
2. Disconnect A/C amplifier 26-pin harness connector. Disconnect speedometer 16-pin harness connector. Check continuity of Green/Red wire between A/C amplifier 26-pin harness connector and speedometer 16-pin harness connector. If continuity exists, inspect speedometer. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. If continuity does not exist, repair Green/Red wire. See «WIRING DIAGRAMS»(ref-98829-S28086467362001052600000) .

1. If discharge air temperature corresponds to temperature control setting, go to next step. If discharge air temperature does not correspond to temperature control setting, go to step 3.
2. Test climate control unit. See «CLIMATE CONTROL UNIT»(ref-98829-S16077541482001052600000) under COMPONENT TESTS. Replace climate control unit if it does not test as specified. If climate control unit tests okay, replace A/C amplifier.
3. Turn ignition on. Measure voltage at terminal 3R of A/C amplifier 20-pin harness connector. (Scheme 25)and see scheme 12. If voltage is 5 volts, go to next step. If voltage is not 5 volts, replace A/C amplifier.
4. Measure voltage at terminal 3S of A/C amplifier 20-pin harness connector. If battery voltage exists, go to next step. If battery voltage does not exist, replace A/C amplifier.
5. Turn ignition switch to LOCK position. Check continuity between ground and terminal 3T of A/C amplifier 20-pin harness connector. see scheme 12 If continuity does not exist, replace A/C amplifier. If continuity exists, check continuity of wire between A/C amplifier and climate control unit. If wire is okay, replace A/C amplifier or climate control unit.

1. If discharge air temperature corresponds to temperature control setting, go to next step. If discharge air temperature does not correspond to temperature control setting, go to step 3.
2. Test climate control unit. See «CLIMATE CONTROL UNIT»(ref-98829-S16077541482001052600000) under COMPONENT TESTS. Replace climate control unit if it does not test as specified. If climate control unit tests okay, replace A/C amplifier.
3. Turn ignition on. Measure voltage at terminal "R" of climate control unit harness connector. (Scheme 26) If voltage is 5 volts, go to next step. If voltage is not 5 volts, replace A/C amplifier.
4. Measure voltage at terminal "S" of climate control unit harness connector. (Scheme 26) If battery voltage exists, go to next step. If battery voltage does not exist, replace A/C amplifier.
5. Turn ignition switch to LOCK position. Check continuity between ground and terminal "T" of climate control unit harness connector. (Scheme 26) If continuity does not exist, replace A/C amplifier. If continuity exists, check continuity of wire between A/C amplifier and climate control unit. If wire is okay, replace A/C amplifier or climate control unit as necessary.

PRELIMINARY INFORMATION

Self-diagnostic function in A/C amplifier locates and indicates system malfunctions in the A/C-heater system. Self-diagnostic function consists of present diagnostic test mode, past diagnostic test mode, and output operation check.

1. Test water temperature sensor. See «WATER TEMPERATURE SENSOR»(ref-98829-S32222008902001052600000) under COMPONENT TESTS. If sensor is okay, go to next step. Replace sensor if it does not test as specified.
2. Disconnect A/C amplifier 22-pin harness connector. Check continuity between Red/Black wire terminal of A/C amplifier harness connector and water temperature sensor harness connector. See «WIRING DIAGRAMS»(ref-98829-S28086467362001052600000) . If continuity exists, go to next step. If continuity does not exist, repair open in Red/Black wire between A/C amplifier and water temperature sensor.
3. Check continuity of Green/Orange wire between A/C amplifier harness connector and water temperature sensor harness connector. If continuity exists, replace A/C amplifier. If continuity does not exist, repair open in Green/Orange wire.

1. Test water temperature sensor. See «WATER TEMPERATURE SENSOR»(ref-98829-S32222008902001052600000) under COMPONENT TESTS. If sensor is okay, go to next step. Replace sensor if it does not test as specified.
2. Disconnect A/C amplifier 16-pin harness connector. Check continuity between Red/Green wire terminal of A/C amplifier harness connector and water temperature sensor harness connector. If continuity exists, go to next step. If continuity does not exist, repair open in Red/Green wire between A/C amplifier and water temperature sensor.
3. Check continuity of Black/Yellow wire between A/C amplifier harness connector and ground. If continuity exists, replace A/C amplifier. If continuity does not exist, repair open in Black/Yellow wire.

1. Start and warm engine to operating temperature. Turn ignition switch to LOCK position. Disconnect A/C amplifier 22-pin and 26-pin harness connectors. Disconnect blower motor harness connector. Using fused jumper wires, apply battery voltage to Blue/Red wire terminal of blower motor connector (component side), and ground Black/White wire terminal (component side).
2. Connect DVOM between either of following set of terminals: Between Pink wire of A/C amplifier 22-pin harness connector and White wire of A/C amplifier 26-pin harness connector. Between Pink wire and Green/Orange wire of A/C amplifier 22-pin harness connector. Go to next step.
3. Using fused jumper wires, apply battery voltage to either A/C amplifier 26-pin harness connector Green/Yellow wire or Green/Black wire. Apply ground to other wire not in use. While observing DVOM, watch for resistance range to vary between 800-5200 ohms as air mix door moves between maximum cold and hot positions. Ensure airflow temperature changes. Reverse fused jumper wires and observe DVOM to confirm resistance change in opposite direction. Perform same resistance check between other set of terminals in step 2 . If resistances are as specified on both circuits, replace A/C amplifier. If resistances are not as specified, check if DTC 18 (present) or DTC 19 (past) is set. If either DTC is set, remove all jumper wires and go to step 5 . If neither DTC is set, remove all jumper wires and go to next step.
4. Remove air mix actuator. Start and warm engine to operating temperature. Set blower switch in fourth speed position. Manually operate air mix crank. If discharge air temperature changes smoothly, go to next step. If temperature does not change smoothly, inspect heater unit.
5. Turn ignition switch to LOCK position. Disconnect A/C amplifier 26-pin harness connector. Check continuity of White wire, Green/Yellow wire and Green/Black wire between air mix actuator harness connector and A/C amplifier 26-pin harness connector. See «WIRING DIAGRAMS»(ref-98829-S28086467362001052600000) . If continuity exists in all wires, go to next step. If continuity does not exist in all wires, repair appropriate wire(s).
6. Disconnect A/C amplifier 22-pin harness connector. Check continuity of Green/Orange and Pink wires between air mix actuator harness connector and A/C amplifier 22-pin harness connector. If continuity exists in all wires, replace air mix actuator. If continuity does not exist, repair appropriate wire(s).

1. Start and warm engine to operating temperature. Turn ignition switch to LOCK position. Disconnect A/C amplifier 16-pin and 20-pin harness connectors. Disconnect blower motor harness connector. Using fused jumper wires, apply battery voltage to Blue/Red wire terminal of blower motor connector (component side), and ground Black/White wire terminal (component side).
2. Connect DVOM between either of following set of terminals: Between Pink wire and Violet/Yellow wire of A/C amplifier 16-pin harness connector. Between Pink wire and Green/Orange wire of A/C amplifier 16-pin harness connector. Go to next step.
3. Using fused jumper wires, apply battery voltage to either A/C amplifier 20-pin harness connector Green/Yellow wire. Apply ground to other Green/Yellow wire. While observing DVOM, watch for resistance range to vary between 800-5200 ohms as air mix door moves between maximum cold and hot positions. Ensure airflow temperature changes. Reverse fused jumper wires and observe DVOM to confirm resistance change in opposite direction. Perform same resistance check between other set of terminals in step 2 . If resistances are as specified on both circuits, replace A/C amplifier. If resistances are not as specified, check if DTC 18 (present) or DTC 19 (past) is set. If either DTC is set, remove all jumper wires and go to step 5 . If neither DTC is set, remove all jumper wires and go to next step.
4. Remove air mix actuator. Start and warm engine to operating temperature. Set blower switch in fourth speed position. Manually operate air mix crank. If discharge air temperature changes smoothly, go to next step. If temperature does not change smoothly, inspect heater unit.
5. Turn ignition switch to LOCK position. Disconnect A/C amplifier 20-pin harness connector. Check continuity of both Green/Yellow wires between air mix actuator harness connector and A/C amplifier 20-pin harness connector. See «WIRING DIAGRAMS»(ref-98829-S28086467362001052600000) . If continuity exists in both wires, go to next step. If continuity does not exist in both wires, repair appropriate wire(s).
6. Disconnect A/C amplifier 16-pin harness connector. Check continuity of Green/Orange wire, Pink wire and Violet/Yellow wire between air mix actuator harness connector and A/C amplifier 16-pin harness connector. If continuity exists in all wires, replace air mix actuator. If continuity does not exist, repair appropriate wire(s).

Note. If DTC 21 (present) or DTC 22 (past) exists, begin at step 2 .

1. Remove airflow mode actuator located above gas pedal. Turn ignition on. Set blower switch at fourth speed setting. Manually operate airflow mode main link. If airflow mode link changes smoothly between vent, bi-level, heat/def and defrost, go to next step. If airflow mode link does not operate as specified, inspect heater unit.
2. Test airflow mode actuator. See «AIRFLOW MODE ACTUATOR»(ref-98829-S38618980112001052600000) under COMPONENT TESTS. If actuator is okay, go to next step. Replace airflow mode actuator if it does not test as specified.
3. Turn ignition switch to LOCK position. Disconnect A/C amplifier 26-pin harness connector. Check continuity of White wire, Yellow wire and Light Green/Black wire between terminals of airflow mode actuator harness connector and A/C amplifier 26-pin harness connector. See «WIRING DIAGRAMS»(ref-98829-S28086467362001052600000) . If continuity is as specified, go to next step. If continuity is not as specified, repair appropriate wire(s).
4. Disconnect A/C amplifier 22-pin harness connector. Check continuity of Blue wire and Green/Orange wire between airflow mode actuator harness connector and A/C amplifier harness connector. If continuity is as specified, replace A/C amplifier. If continuity is not as specified, repair appropriate wire(s).

Note. If DTC 21 (present) or DTC 22 (past) exists, begin at step 2 .

1. Remove airflow mode actuator located above gas pedal. Turn ignition on. Set blower switch at fourth speed setting. Manually operate airflow mode main link. If airflow mode link changes smoothly between vent, bi-level, heat/def and defrost, go to next step. If airflow mode link does not operate as specified, inspect heater unit.
2. Test airflow mode actuator. See «AIRFLOW MODE ACTUATOR»(ref-98829-S38618980112001052600000) under COMPONENT TESTS. If actuator is okay, go to next step. Replace airflow mode actuator if it does not test as specified.
3. Turn ignition switch to LOCK position. Disconnect A/C amplifier 20-pin harness connector. Check continuity of Yellow wire and Light Green/Black wire between terminals of airflow mode actuator harness connector and A/C amplifier 20-pin harness connector. If continuity is as specified, go to next step. If continuity is not as specified, repair appropriate wire(s). See «WIRING DIAGRAMS»(ref-98829-S28086467362001052600000) .
4. Disconnect A/C amplifier 16-pin harness connector. Check continuity of Blue wire, Green/Orange wire and Violet/Yellow wire between airflow mode actuator harness connector and A/C amplifier 16-pin harness connector. If continuity is as specified, replace A/C amplifier. If continuity is not as specified, repair appropriate wire(s).

SYSTEM TESTS

A/C SYSTEM PERFORMANCE

1. Install manifold gauge set. Place a thermometer in center vent outlet. Close all doors and windows. With engine at normal operating temperature, set engine to 1500 RPM. Depress AUTO switch. Set temperature to 65°F (18°C). Allow A/C output temperature to stabilize.
2. Compare ambient temperature to both high-side and low-side pressure readings. See «A/C SYSTEM PERFORMANCE PRESSURES (2000)»(ref-98829-S16077117492001052600000) or «A/C SYSTEM PERFORMANCE PRESSURES (2001)»(ref-98829-S01521246962001060700000) table. If pressure readings are as specified, system is okay. If pressure readings are not as specified, go to «TEST NO. 18: AIR FROM VENTS NOT COLD ENOUGH»(ref-98829-S03224944172001052600000) under SYMPTOM TESTS.

A/C SYSTEM PERFORMANCE PRESSURES (2000)

A/C SYSTEM PERFORMANCE PRESSURES (2001)

1. Remove climate control unit. See «CLIMATE CONTROL UNIT»(ref-98829-S06174307582001052600000) under REMOVAL & INSTALLATION. Disconnect A/C amplifier 20-pin harness connector. (Scheme 25)and see scheme 12. Using DVOM, backprobe between indicated terminals of A/C amplifier 20-pin harness connector. See «CLIMATE CONTROL UNIT CONTINUITY TEST (2000)»(ref-98829-S27555110732001052600000) table. If continuity is as specified, go to next step. If continuity is not as specified, replace climate control unit.
2. Using DVOM, backprobe between terminals 3J and 3L of A/C amplifier 20-pin harness connector. see scheme 12 If continuity exists, go to next step. If continuity does not exist, replace climate control unit.
3. Apply positive battery voltage to terminal 3N of A/C amplifier 20-pin harness connector. Ground indicated terminal, and ensure appropriate LED indicator comes on. See «CONTROL SWITCH LED INDICATOR TEST (2000)»(ref-98829-S39931925542001052600000) table. Replace climate control unit if results are not as specified.

CLIMATE CONTROL UNIT CONTINUITY TEST (2000)

CONTROL SWITCH LED INDICATOR TEST (2000)

1. Remove climate control unit. See «CLIMATE CONTROL UNIT»(ref-98829-S06174307582001052600000) under REMOVAL & INSTALLATION. Disconnect climate control unit 20-pin harness connector. (Scheme 25)and (Scheme 26). Using DVOM, backprobe between indicated terminals of climate control unit 20-pin harness connector. See «CLIMATE CONTROL UNIT CONTINUITY TEST (2001)»(ref-98829-S09807596352001061300000) table. If continuity is as specified, go to next step. If continuity is not as specified, replace climate control unit.
2. Using DVOM, backprobe between terminals "J" and "L" of A/C amplifier 20-pin harness connector. (Scheme 26) If continuity exists, go to next step. If continuity does not exist, replace climate control unit.
3. Apply positive battery voltage to terminal "N" of climate control unit 20-pin harness connector. Ground indicated terminal, and ensure appropriate LED indicator comes on. See «CONTROL SWITCH LED INDICATOR TEST (2001)»(ref-98829-S18840123122001061300000) table. Replace climate control unit if results are not as specified. CLIMATE CONTROL UNIT CONTINUITY TEST (2001) Test Condition (1) Continuity Between Terminals No. Fan O & H A/C O & F MODE O & D Windshield Defrost O & B Air Intake Selector Q & H Rear Defrost Q & F OFF Q & D AUTO Q & B (1) Press indicated control switch to the on position. CONTROL SWITCH LED INDICATOR TEST (2001) Terminal LED Indicator 3E AUTO 3G Defrost 3I Recirculated Air 3K Rear Defrost 3M Fresh Air

AIR INTAKE ACTUATOR

1. Disconnect intake air actuator harness connector. Remove actuator. Apply positive battery voltage to terminal "J" of air intake actuator connector, and ground to terminal "I". (Scheme 27) Actuator should rotate from fresh air to 1/3 fresh air and then to recirculated air position. Reverse battery polarity, and verify actuator rotates in reverse direction. Replace actuator if it does not operate as specified.
2. If actuator operates as specified, check continuity between indicated terminals of air intake actuator harness connector. See «AIR INTAKE ACTUATOR CONTINUITY TEST»(ref-98829-S08355438752001052600000) table. Replace air intake actuator if continuity is not as specified.

AIR INTAKE ACTUATOR CONTINUITY TEST

Scheme 27

1. Disconnect airflow mode actuator connector. Airflow mode actuator is located above gas pedal. Remove actuator. Apply battery voltage to terminal "G" of airflow mode actuator harness connector, and ground to terminal "H". (Scheme 28) Ensure actuator moves to Defroster mode.
2. Connect DVOM between terminals "A" and "B" of actuator harness connector. While observing DVOM, reverse battery polarity between terminals "G" and "H" of actuator harness connector. Ensure resistance reading changes progressively from 800 ohms to 5200 ohms as actuator moves from vent mode to defrost mode. Replace actuator if it does not test as specified.

Scheme 28

1. Remove dashboard. See «DASHBOARD»(ref-98829-S28868219682001052600000) under REMOVAL & INSTALLATION. Disconnect air mix actuator harness connector. Apply battery voltage to terminal "F" of air mix actuator harness connector, and ground to terminal "E". (Scheme 29) Ensure air mix door moves to full cold position.
2. Connect DVOM between terminals "A" and "B" of actuator harness connector. (Scheme 29) While observing DVOM, reverse battery polarity between terminals "F" and "E" of actuator harness connector. Ensure resistance reading changes progressively from 800 ohms to 5200 ohms as air mix door moves from maximum cold position to maximum hot position. Replace actuator if it does not test as specified.

Scheme 29

BLOWER MOTOR

Remove blower motor. Disconnect blower motor harness connector. Apply battery voltage between blower motor terminals. If blower motor does not operate, replace blower motor.

CONDENSER FAN

Disconnect condenser fan harness connector. Apply positive battery voltage to terminal "A" (Blue/Green wire) of condenser fan harness connector, and ground terminal "B" (Green wire). Replace condenser fan if it does not operate.

4-Pin Relays

Remove relay to be tested. Check continuity between relay terminals "C" and "D". (Scheme 30) Ensure continuity does not exist. Apply battery voltage to relay terminal "A", and ground terminal "B". Ensure continuity is now present between relay terminals "C" and "D". Replace relay if continuity is not as specified.

5-Pin Relays

Remove relay to be tested. Check continuity between relay terminals "C" and "F". (Scheme 31) Ensure continuity exists. Apply battery voltage to terminals "A" and "B". Ensure continuity exists between relay terminals "C" and "E". Replace relay if continuity is not as specified.

Scheme 30

Scheme 31

AMBIENT TEMPERATURE SENSOR

1. Turn ignition off. Remove radiator grille to access ambient temperature sensor. Disconnect ambient temperature sensor harness connector. Remove sensor. Measure air temperature near sensor. Measure resistance across ambient temperature sensor connector terminals.
2. Ensure resistance is within specifications. (Scheme 32) Replace ambient temperature sensor if resistance is not within specification.

Scheme 32

EVAPORATOR TEMPERATURE SENSOR

1. Turn ignition and A/C switches off. Remove dashboard undercover and glove box to access evaporator temperature sensor. Disconnect evaporator sensor harness connector. Ensure evaporator surface temperature equals surrounding temperature. Place blower switch in fourth speed position. Set air intake selector switch in recirculated air mode.
2. Measure temperature at blower inlet. Measure resistance across evaporator temperature sensor harness connector terminals. Ensure resistance is within specification. (Scheme 32) Replace evaporator temperature sensor if resistance is not within specification.

Turn ignition off. Remove PCT sensor located at lower right corner of passenger side of instrument panel. Disconnect air hose and PCT sensor harness connector. Measure air temperature near PCT sensor. Measure resistance across PCT sensor harness connector terminals. Ensure resistance is within specification. (Scheme 32) Replace PCT sensor if resistance is not within specification.

1. Turn ignition off. Remove PCT sensor located at rear of center instrument panel. Disconnect air hose and PCT sensor harness connector. Measure air temperature near PCT sensor. Measure resistance across PCT sensor harness connector terminals "B" and "D". (Scheme 33) Ensure resistance is within specification. (Scheme 32) Replace PCT sensor if resistance is not within specification.
2. Using fused jumper wires, connect battery voltage to PCT sensor terminal "A" and ground to terminal "C". PCT sensor fan should operate. If fan does not operate, replace PCT sensor.

Scheme 33

POWER TRANSISTOR

Remove power transistor (MOS FET). Disconnect MOS FET harness connector. Using DVOM, measure voltage between indicated terminals. (Scheme 34) See POWER TRANSISTOR (MOS FET) RESISTANCE table. Replace power transistor if voltage is not as specified.

POWER TRANSISTOR (MOS FET) RESISTANCE

Scheme 34

REFRIGERANT PRESSURE SWITCH

Connect manifold pressure gauge set. Ensure high-side refrigerant pressure is 32-480 psi (2.3-34 kg/cm 2 ). Disconnect refrigerant pressure switch. Using DVOM, check continuity across pressure switch terminals. If continuity exists, pressure switch is okay. Replace pressure switch if continuity does not exist.

SOLAR RADIATION SENSOR

Turn ignition off. Pry solar radiation sensor from instrument panel using small screwdriver. Disconnect sensor harness connector. Connect voltmeter positive lead to White wire (2000) or Violet/Yellow wire (2001) terminal of solar radiation sensor harness connector, and negative lead to Red/Yellow wire terminal. Place a 60-watt light about 3.9" (10 cm) from sensor. Replace solar radiation sensor if output voltage is not at least 0.45 volts.

1. Turn ignition off. Remove right side dashboard undercover and glove box to access water temperature sensor. Disconnect water temperature sensor harness connector and remove sensor. Measure air temperature near water temperature sensor. Measure resistance across water temperature sensor harness connector terminals.
2. Ensure resistance is within specification. (Scheme 35) Replace water temperature sensor if resistance is not within specification.

Scheme 35