Nissan Maxima Service and Repair Manual: Magnet clutch

Description

SYSTEM DESCRIPTION

A/C auto amp. controls A/C compressor operation by ambient temperature and signal from ECM.

Low Temperature Protection Control A/C auto amp. will turn the A/C compressor ON or OFF as determined by a signal detected by ambient sensor.

When ambient temperature is greater than 4C (39F), the A/C compressor turns ON. The A/C compressor turns OFF when ambient temperature is less than 2.5C (37F).

Component Function Check

1.FUNCTION INSPECTIONS

1. Press AUTO switch. AUTO is indicated on the display.
2. Press the A/C switch.
3. Check that the indicator of the A/C switch turns on. Check visually and by sound that the A/C compressor is operating. (The discharge air temperature or fan speed varies depending on the ambient temperature, in-vehicle temperature, and temperature setting.)
4. Press the A/C switch again.
5. Check that the indicator of the A/C switch turns OFF. Check visually and by sound that the A/C compressor stops.

Diagnosis Procedure

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

1.INSPECTION IN AUTO ACTIVE TEST MODE

Perform "AUTO ACTIVE TEST".

2.CHECK POWER SUPPLY FOR A/C COMPRESSOR

1. Turn ignition switch OFF.
2. Disconnect A/C compressor connector.
3. Start engine and press A/C switch.
4. Check voltage between A/C compressor harness connector F3 terminal 1 and ground.

3.CHECK FUSE

Check 10A fuse (No. 41) located in IPDM E/R.

4.CHECK CIRCUIT CONTINUITY BETWEEN A/C RELAY IN IPDM E/R AND A/C COMPRESSOR

1. Turn ignition switch OFF.
2. Disconnect IPDM E/R connector F10 and A/C compressor connector F3.
3. Check continuity between A/C compressor harness connector F3 (A) terminal 1 and IPDM E/R harness connector F10 (B) terminal 48.

1 - 48: Continuity should exist.

5.CHECK A/C COMPRESSOR CIRCUIT FOR SHORT

Check continuity between A/C compressor harness connector F3 terminal 1 and ground.

1 - Ground: Continuity should not exist.

6.CHECK WITH SELF-DIAGNOSIS FUNCTION OF CONSULT

1. Using CONSULT, perform "SELF-DIAGNOSIS RESULTS" of HVAC.
2. Check if any DTC No. is displayed in the self-diagnosis results.

NOTE: If DTC is displayed along with DTC U1000 or U1010, first diagnose the DTC U1000 or U1010.

7.CHECK A/C AUTO AMP. INPUT SIGNAL

Using CONSULT, check "On/Off" of "COMP REQ SIG" and "FAN REQ SIG" in "DATA MONITOR" of HVAC.

A/C SWITCH ON: COMP REQ SIG On
A/C SWITCH OFF: COMP REQ SIG Off
FAN CONTROL DIAL ON: FAN REQ SIG On
FAN CONTROL DIAL OFF: FAN REQ SIG Off

8.CHECK REFRIGERANT PRESSURE SENSOR

Check refrigerant pressure sensor.