Automatic Air Conditioner: Diagnosis Nissan Maxima A34

Wiring Diagrams and Trouble Diagnosis

When you read wiring diagrams, refer to the following

1. «HOW TO READ WIRING DIAGRAMS»(ref-233642-S29809225742006052600000)
2. «POWER SUPPLY ROUTING CIRCUIT»(ref-233661-S18989168572006052600000)

When you perform trouble diagnosis, refer to the following

1. «HOW TO FOLLOW TROUBLE DIAGNOSES»(ref-233642-S24641668712006052600000)
2. «HOW TO PERFORM EFFICIENT DIAGNOSIS FOR AN ELECTRICAL INCIDENT»(ref-233642-S21861505242006052600000)

SELF-DIAGNOSTIC SYSTEM

The self-diagnostic system is built into the unified meter and A/C amp. to quickly locate the cause of symptoms.

DIAGNOSTIC PROCEDURE FOR A/C SYSTEM

SYMPTOM: A/C system does not come on.

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1. CHECK POWER SUPPLY CIRCUIT FOR UNIFIED METER AND A/C AMP. Disconnect unified meter and A/C amp. connector. Check voltage between unified meter and A/C amp. harness connector M50 terminals 21 (Y/R), 22 (G) and 35 (V), unified meter and A/C amp. harness connector M89 terminal 46 (W/L) and ground. OK or NG OK: GO TO 2 . NG: Check 10A and 15A fuses [Nos. 6,10,12 and 19, located in the fuse block (J/B)]. Refer to «FUSE BLOCK-JUNCTION BOX(J/B)»(ref-233661-S09945532042006052600000) . If fuses are OK, check harness for open circuit. Repair or replace as necessary. If fuses are NG, replace fuse and check harness for short circuit. Repair or replace as necessary.
2. CHECK GROUND CIRCUIT FOR UNIFIED METER AND A/C AMP. Turn ignition switch OFF. Check continuity between unified meter and A/C amp. harness connector M50 terminal 29 (B), 30 (B) and ground. 29, 30 - Ground: Continuity should exist. OK or NG OK: Replace unified meter and A/C amp. NG: Repair harness or connector.

DIAGNOSTIC PROCEDURE FOR MODE DOOR MOTOR

SYMPTOM: Mode door motor does not operate normally.

Perform diagnostic procedure for LAN circuit. Refer to DIAGNOSTIC PROCEDURE FOR LAN CIRCUIT .

DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR

Perform diagnostic procedure for LAN circuit. Refer to DIAGNOSTIC PROCEDURE FOR LAN CIRCUIT .

DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR PBR

Perform diagnostic procedure for LAN circuit. Refer to DIAGNOSTIC PROCEDURE FOR LAN CIRCUIT .

DIAGNOSTIC PROCEDURE FOR INTAKE DOOR MOTOR

SYMPTOM: Intake door motor does not operate normally.

Perform diagnostic procedure for LAN system circuit. Refer to DIAGNOSTIC PROCEDURE FOR LAN CIRCUIT .

DIAGNOSTIC PROCEDURE FOR BLOWER MOTOR

SYMPTOM: Blower motor operation is malfunctioning under starting fan speed control.

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1. CHECK POWER SUPPLY FOR FAN CONTROL AMP. Disconnect fan control amp. connector. Turn ignition switch ON. Check voltage between fan control amp. harness connector M64 terminal 3 (L/R) and ground. OK or NG OK: GO TO 2 . NG: GO TO 7 .
2. CHECK FAN FEEDBACK CIRCUIT Disconnect unified meter and A/C amp. Check voltage between unified meter and A/C amp. harness connector M89 terminal 47 (L/R) and ground. OK or NG OK: GO TO 3 . NG: Check for open circuit in wiring harness. Repair or replace as necessary.
3. CHECK BODY GROUND CIRCUIT FOR FAN CONTROL AMP. Turn ignition switch OFF. Check continuity between fan control amp. harness connector M64 terminal 1 (B) and ground. OK or NG OK: Reconnect fan control amp. and unified meter A/C amp. harness connectors and GO TO 4 . NG: Repair harness or connector.
4. CHECK VOLTAGE FOR FAN CONTROL AMP. Turn ignition switch ON. Turn fan dial to any position except OFF or AUTO. Check voltage between fan control amp. harness connector M64 terminal 2 (L/Y) and ground. OK or NG OK: Replace fan control amp. Confirm that blower motor operation is normal. NG: GO TO 5 .
5. CHECK FAN CONTROL AMP. CIRCUIT BETWEEN FAN CONTROL AMP. AND UNIFIED METER AND A/C AMP. Turn ignition switch OFF. Disconnect unified meter and A/C amp. and fan control amp. harness connectors. Check continuity between fan control amp. harness connector M64 terminal 2 (L/Y) and unified meter and A/C amp. harness connector M89 terminal 60 (L/Y). If OK, check harness for short. OK or NG OK: GO TO 6 . NG: Repair harness or connector.
6. CHECK POWER SUPPLY FOR UNIFIED METER AND A/C AMP. Turn ignition switch ON. Check voltage between unified meter and A/C amp. harness connector M89 terminal 46 (W/L) and ground. OK or NG OK: Replace unified meter and A/C amp. Refer to «REMOVAL AND INSTALLATION»(ref-233653-S40720475752006052600000) . Confirm that blower motor operation is normal. NG: Check for open circuit in wiring harness. Repair or replace as necessary. If OK, replace fuse and check wiring harness for short circuit. Repair or replace as necessary.
7. CHECK POWER SUPPLY FOR BLOWER MOTOR Disconnect blower motor harness connector. Check voltage between blower motor harness connector M62 terminal 1 (W/L) and ground. OK or NG OK: GO TO 8 . NG: Check power supply circuit and 15A fuses [Nos. 10 and 11, located in the fuse block (J/B)]. If OK, check for open circuit in wiring harness. Repair or replace as necessary. If OK, replace fuse and check wiring harness for short circuit. Repair or replace as necessary.
8. CHECK CIRCUIT CONTINUITY BETWEEN BLOWER MOTOR AND FAN CONTROL AMP. Turn ignition OFF. Check continuity between blower motor harness connector M62 terminal 2 (L/R) and fan control amp. harness connector M64 terminal 3 (L/R). OK or NG OK: Check blower motor. Refer to «BLOWER MOTOR»(ref-233653-S11881523042006052600000) . If NG, replace blower motor. Confirm that blower motor operation is normal. NG: Repair harness or connector.

DIAGNOSTIC PROCEDURE FOR MAGNET CLUTCH

SYMPTOM: Magnet clutch does not engage when A/C switch is ON.

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1. CHECK INTAKE SENSOR CIRCUIT Check intake sensor. Refer to «FUNCTION CONFIRMATION PROCEDURE»(ref-233653-S11587726622006052600000) . OK or NG OK: GO TO 2 . NG: Malfunctioning intake sensor: Refer to «INTAKE SENSOR CIRCUIT»(ref-233653-S41784476492006052600000) .
2. PERFORM AUTO ACTIVE TEST Refer to «AUTO ACTIVE TEST»(ref-233661-S03416427522006052600000) . Does magnet clutch operate? YES or NO YES: WITH CONSULT-II GO TO 5 . WITHOUT CONSULT-II GO TO 6 . NO: Check 10A fuse (No. 33, located in IPDM E/R), and GO TO 3 .
3. CHECK CIRCUIT CONTINUITY BETWEEN IPDM E/R AND COMPRESSOR Turn ignition switch OFF. Disconnect IPDM E/R connector and compressor (magnet clutch) connector. Check continuity between IPDM E/R harness connector E124 terminal 33 (Y/B) and compressor harness connector F3 terminal 1 (Y/B). 33-1: Continuity should exist. OK or NG OK: GO TO 4 . NG: Repair harness or connector.
4. CHECK MAGNET CLUTCH OPERATION Check for operation sound when applying battery voltage direct current to terminal. OK or NG OK: Replace IPDM E/R. NG: Replace magnet clutch. Refer to «REMOVAL AND INSTALLATION FOR COMPRESSOR CLUTCH»(ref-233653-S06628897662006052600000) .
5. CHECK BCM INPUT (COMPRESSOR ON) SIGNAL Check compressor ON/OFF signal. Refer to «CONSULT-II FUNCTION (METER A/C AMP)»(ref-233653-S42621250402006052600000) . A/C SW ON: COMP ON SIG ON A/C SW OFF: COMP ON SIG OFF OK or NG OK: GO TO 8 . NG: GO TO 6 .
6. CHECK CIRCUIT CONTINUITY BETWEEN BCM AND UNIFIED METER AND A/C AMP. Turn ignition switch OFF. Disconnect BCM connector and unified meter and A/C amp. connector. Check continuity between BCM harness connector M18 terminal 27 (O/L) and unified meter and A/C amp. harness connector M89 terminal 42 (O/L). 27 - 42: Continuity should exist. OK or NG OK: GO TO 7 . NG: Repair harness or connector.
7. CHECK VOLTAGE FOR UNIFIED METER AND A/C AMP. (COMPRESSOR ON SIGNAL) Reconnect BCM connector and unified meter and A/C amp. connector. Turn ignition switch ON. Check voltage between unified meter and A/C amp. harness connector M89 terminal 42 (O/L) and ground. OK or NG OK: GO TO 8 . NG-1: If the voltage is approx. 5V A/C switch is ON: Replace unified meter and A/C amp. NG-2: If the voltage is approx. 0V when A/C switch is OFF: Replace BCM.
8. CHECK REFRIGERANT PRESSURE SENSOR WITH CONSULT-II Start engine. Check voltage of refrigerant pressure sensor. Refer to «CONSULT-II FUNCTION (METER A/C AMP)»(ref-233653-S42621250402006052600000) . WITHOUT CONSULT-II Start engine. Check voltage between ECM harness connector F54 terminal 70 (W) and ground. OK or NG OK: WITH CONSULT-II GO TO 9 . WITHOUT CONSULT-II GO TO 10 . NG: Refer to «REFRIGERANT PRESSURE SENSOR»(ref-233653-S34559385982006052600000) .
9. CHECK BCM INPUT (FAN ON) SIGNAL Check FAN ON/OFF signal. Refer to «CONSULT-II FUNCTION (METER A/C AMP)»(ref-233653-S42621250402006052600000) . FAN CONTROL SWITCH ON: FAN ON SIG ON FAN CONTROL SWITCH OFF: FAN ON SIG OFF OK or NG OK: GO TO 12 . NG: GO TO 10 .
10. CHECK CIRCUIT CONTINUITY BETWEEN BCM AND UNIFIED METER AND A/C AMP. Turn ignition switch OFF. Disconnect BCM connector and unified meter and A/C amp. connector. Check continuity between BCM harness connector M18 terminal 28 (W/B) and unified meter and A/C amp. harness connector M89 terminal 57 (W/B). 28 - 57: Continuity should exist. OK or NG OK: GO TO 11 . NG: Repair harness or connector.
11. CHECK VOLTAGE FOR UNIFIED METER AND A/C AMP. (FAN ON SIGNAL) Reconnect BCM connector and unified meter and A/C amp. connector. Turn ignition switch ON. Check voltage between unified meter and A/C amp. harness connector M89 terminal 57 (W/B) and ground. OK or NG OK: GO TO 12 . NG-1: If the voltage is approx. 5V when blower motor is ON: Replace unified meter and A/C amp. NG-2: If the voltage is approx. 0V when blower motor is OFF: Replace BCM. Refer to «REMOVAL AND INSTALLATION OF BCM»(ref-233675-S19678858802006052600000) .
12. CHECK CAN COMMUNICATION Check CAN communication. Refer to «DIAGNOSTIC PROCEDURE FOR LAN CIRCUIT»(ref-233653-S17003931612006052600000) . BCM - ECM ECM - IPDME/R ECM - Unified meter and A/C amp. OK or NG OK: Inspection End NG: Repair or replace malfunctioning part(s).

Test Condition

Testing must be performed as follows

PERFORMANCE CHART

Test Reading

Recirculating-to-discharge Air Temperature Table

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Ambient Air Temperature-to-operating Pressure Table

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TROUBLE DIAGNOSES FOR UNUSUAL PRESSURE

Whenever system's high and/or low side pressure is unusual, diagnose using a manifold gauge. The marker above the gauge scale in the following tables indicates the standard (usual) pressure range. Since the standard (usual) pressure, however, differs from vehicle to vehicle, refer to above table (Ambient air temperature-to-operating pressure table).

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Self-diagnosis

SYMPTOM: Self-diagnosis cannot be performed.

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DIAGNOSTIC PROCEDURE FOR AMBIENT SENSOR

SYMPTOM: Ambient sensor circuit is open or shorted. (21 or - 21 is indicated on unified meter and A/C amp. As a result of conducting Self-diagnosis STEP- 2 .)

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1. CHECK VOLTAGE BETWEEN AMBIENT SENSOR AND GROUND Disconnect ambient sensor connector. Turn ignition switch ON. Check voltage between ambient sensor harness connector E1 terminal 1 (O/B) and ground. 1 - Ground: Approx. 5V OK or NG OK: GO TO 2 . NG: GO TO 4 .
2. CHECK CIRCUIT CONTINUITY BETWEEN AMBIENT SENSOR AND UNIFIED METER AND A/C AMP. Turn ignition switch OFF. Disconnect unified meter and A/C amp. connector. Check continuity between ambient sensor harness connector E1 terminal 2 (B/Y) and unified meter and A/C amp. harness connector M89 terminal 49 (B/Y). 2-49: Continuity should exist. OK or NG OK: GO TO 3 . NG: Repair harness or connector.
3. CHECK AMBIENT SENSOR Refer to «AMBIENT SENSOR»(ref-233653-S25224043372006052600000) . OK or NG OK: Replace unified meter and A/C amp. Go to self-diagnosis «FUNCTION CONFIRMATION PROCEDURE»(ref-233653-S11587726622006052600000) and perform self-diagnosis STEP- 2 . Confirm that code No. 20 is displayed. NG: Replace ambient sensor. Go to self-diagnosis «FUNCTION CONFIRMATION PROCEDURE»(ref-233653-S11587726622006052600000) and perform self-diagnosis STEP- 2 . Confirm that code No. 20 is displayed.
4. CHECK CIRCUIT CONTINUITY BETWEEN AMBIENT SENSOR AND UNIFIED METER AND A/C AMP. Turn ignition switch OFF. Disconnect unified meter and A/C amp. connector. Check continuity between ambient sensor harness connector E1 terminal 1 (O/B) and unified meter and A/C amp. harness connector M89 terminal 39 (O/B). 1-39: Continuity should exist. Check continuity between ambient sensor harness connector E1 terminal 1 (O/B) and ground. 1 - Ground: Continuity should not exist. OK or NG OK: Replace unified meter and A/C amp. Go to self-diagnosis «FUNCTION CONFIRMATION PROCEDURE»(ref-233653-S11587726622006052600000) and perform self-diagnosis STEP- 2 . Confirm that code No. 20 is displayed. NG: Repair harness or connector.

DIAGNOSTIC PROCEDURE FOR IN-VEHICLE SENSOR

SYMPTOM: In-vehicle sensor circuit is open or shorted. (22 or -22 is indicated on unified meter and A/C amp. as a result of conducting Self-diagnosis STEP- 2 .)

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1. CHECK VOLTAGE BETWEEN IN-VEHICLE SENSOR AND GROUND Disconnect in-vehicle sensor connector. Turn ignition switch ON. Check voltage between in-vehicle sensor harness connector M32 terminal 1 (LG) and ground. 1-Ground: Approx. 5 V OK or NG OK: GO TO 2 . NG: GO TO 4 .
2. CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR AND UNIFIED METER AND A/C AMP. Turn ignition switch OFF. Disconnect unified meter and A/C amp. connector. Check continuity between in-vehicle sensor harness connector M32 terminal 2 (B/Y) and unified meter and A/C amp. harness connector M89 terminal 49 (B/Y). 2 -49: Continuity should exist. OK or NG OK: GO TO 3 . NG: Repair harness or connector.
3. CHECK IN-VEHICLE SENSOR Refer to «IN-VEHICLE SENSOR»(ref-233653-S10396146402006052600000) . OK or NG OK: Replace unified meter and A/C amp. Go to self-diagnosis «FUNCTION CONFIRMATION PROCEDURE»(ref-233653-S11587726622006052600000) and perform self-diagnosis STEP 2 . Confirm that code No. 20 is displayed. NG: Replace in-vehicle sensor. Go to self-diagnosis «FUNCTION CONFIRMATION PROCEDURE»(ref-233653-S11587726622006052600000) and perform self-diagnosis STEP 2 . Confirm that code No. 20 is displayed.
4. CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR AND UNIFIED METER AND A/C AMP. Turn ignition switch OFF. Disconnect unified meter and A/C amp. connector. Check continuity between in-vehicle sensor harness connector M32 terminal 1 (LG) and unified meter and A/C amp. harness connector M89 terminal 40 (LG). 1 - 40: Continuity should exist. Check continuity between in-vehicle sensor harness connector M32 terminal 1 (LG) and ground. 1 - Ground: Continuity should not exist. OK or NG OK: Replace unified meter and A/C amp. Go to self-diagnosis «FUNCTION CONFIRMATION PROCEDURE»(ref-233653-S11587726622006052600000) and perform self-diagnosis STEP 2. Confirm that code No. 20 is displayed. NG: Repair harness or connector.

DIAGNOSTIC PROCEDURE FOR SUNLOAD SENSOR

SYMPTOM: Sunload sensor circuit is open or shorted. (25 or -25 is indicated on unified meter and A/C amp. as a result of conducting Self-diagnosis STEP- 2 .)

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1. CHECK VOLTAGE BETWEEN SUNLOAD SENSOR AND GROUND Disconnect sunload sensor connector. Turn ignition switch ON. Check voltage between sunload sensor harness connector M65 terminal 1 (O) and ground. 1 - Ground: Approx. 5V OK or NG OK: GO TO 2 . NG: GO TO 4 .
2. CHECK CIRCUIT CONTINUITY BETWEEN SUNLOAD SENSOR AND UNIFIED METER AND A/C AMP. Turn ignition switch OFF. Disconnect unified meter and A/C amp. connector. Check continuity between sunload sensor harness connector M65 terminal 2 (B/Y) and unified meter and A/C amp. harness connector M89 terminal 49 (B/Y). 2 - 49: Continuity should exist. OK or NG OK: GO TO 3 . NG: Repair harness or connector.
3. CHECK SUNLOAD SENSOR Refer to «SUNLOAD SENSOR»(ref-233653-S20414947772006052600000) . OK or NG OK: Replace unified meter and A/C amp. Go to self-diagnosis «FUNCTION CONFIRMATION PROCEDURE»(ref-233653-S11587726622006052600000) and perform self-diagnosis STEP- 2 . Confirm that code No. 20 is displayed. NG: Replace sunload sensor. Go to self-diagnosis «FUNCTION CONFIRMATION PROCEDURE»(ref-233653-S11587726622006052600000) and perform self-diagnosis STEP- 2 . Confirm that code No. 20 is displayed.
4. CHECK CIRCUIT CONTINUITY BETWEEN SUNLOAD SENSOR AND UNIFIED METER AND A/C AMP. Turn ignition switch OFF. Disconnect unified meter and A/C amp. connector. Check continuity between sunload sensor harness connector M65 terminal 1 (O) and display and unified meter and A/C amp. harness connector M89 terminal 50 (O). 1 - 50: Continuity should exist. Check continuity between sunload sensor harness connector M65 terminal 1 (O) and ground. 1 - Ground: Continuity should not exist. OK or NG OK: Replace unified meter and A/C amp. Go to self-diagnosis «FUNCTION CONFIRMATION PROCEDURE»(ref-233653-S11587726622006052600000) and perform self-diagnosis STEP- 2 . Confirm that code No. 20 is displayed. NG: Repair harness or connector.

DIAGNOSTIC PROCEDURE FOR INTAKE SENSOR

SYMPTOM: Intake sensor circuit is open or shorted. (24 or -24 is indicated on unified meter and A/C amp. as a result of conducting Self-diagnosis STEP 2 .)

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1. CHECK VOLTAGE BETWEEN INTAKE SENSOR AND GROUND Disconnect intake sensor connector. Turn ignition switch ON. Check voltage between intake sensor harness connector M33 terminal 1 (R/W) and ground. 1 - Ground: Approx. 5V OK or NG OK: GO TO 2 . NG: GO TO 4 .
2. CHECK CIRCUIT CONTINUITY BETWEEN INTAKE SENSOR AND UNIFIED METER AND A/C AMP. Turn ignition switch OFF. Disconnect unified meter and A/C amp. connector. Check continuity between intake sensor harness connector M33 terminal 2 (B/Y) and unified meter and A/C amp. harness connector M89 terminal 49 (B/Y). 2 - 49: Continuity should exist. OK or NG OK: GO TO 3 . NG: Repair harness or connector.
3. CHECK INTAKE SENSOR Refer to «INTAKE SENSOR»(ref-233653-S11715937762006052600000) . OK or NG OK: Replace unified meter and A/C amp. Go to self-diagnosis «FUNCTION CONFIRMATION PROCEDURE»(ref-233653-S11587726622006052600000) and perform self-diagnosis STEP 2 . Confirm that code No. 20 is displayed. NG: Replace intake sensor. Go to self-diagnosis «FUNCTION CONFIRMATION PROCEDURE»(ref-233653-S11587726622006052600000) and perform self-diagnosis STEP 2 . Confirm that code No. 20 is displayed.
4. CHECK CIRCUIT CONTINUITY BETWEEN INTAKE SENSOR AND UNIFIED METER AND A/C AMP. Turn ignition switch OFF. Disconnect unified meter and A/C amp. connector. Check continuity between intake sensor harness connector M33 terminal 1 (R/W) and unified meter and A/C amp. harness connector M89 terminal 41 (R/W). 1 - 41: Continuity should exist. Check continuity between intake sensor harness connector M33 terminal 1 (R/W) and ground. 1 - Ground: Continuity should not exist. OK or NG OK: Replace unified meter and A/C amp. Go to self-diagnosis «FUNCTION CONFIRMATION PROCEDURE»(ref-233653-S11587726622006052600000) and perform self-diagnosis STEP 2 . Confirm that code No. 20 is displayed. NG: Repair harness or connector.

INSPECTION AFTER INSTALLATION

Check the clearance all the way around the clutch disc as shown.

Clutch disc-to-pulley clearance: 0.3 - 0.6 mm

(0.012 - 0.024 in)

If the specified clearance is not obtained, replace the adjusting spacer and recheck the clearance.

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