Nissan Maxima Service and Repair Manual: Cooling fan
Description
The ECM controls the cooling fan corresponding to the vehicle speed, engine
coolant temperature, refrigerant
pressure, and air conditioner ON signal. The control system has 4-step control
[HIGH/MIDDLE/LOW/OFF].
COOLING FAN MOTOR
The cooling fan operates at each speed when the current flows in the cooling
fan motor as per the following.

The cooling fan operates at low (LOW) speed when cooling fan motors-1 and -2
are circuited in series under
the middle speed condition.
Component Function Ch
1.CHECK COOLING FAN FUNCTION
With CONSULT
- Turn ignition switch ON.
- Perform "COOLING FAN" in "ACTIVE TEST" mode with CONSULT.
- Check that cooling fan speed varies according to the percentage.
Without CONSULT
- Perform IPDM E/R auto active test and check cooling fan motors
operation, refer to PCS-11, "Diagnosis
Description".
- Check that cooling fan operates.
Diagnosis Procedure
1.CHECK COOLING FAN RELAY POWER SUPPLY CIRCUIT

- Turn ignition switch OFF.
- Disconnect cooling fan relays-2, -3.
- Turn ignition switch ON.
- Check the voltage between cooling fan relays-2, -3 harness
connectors
and ground.

2.DETECT MALFUNCTIONING PART
Check the following.
- 10 A fuse (No. 33)
- 40 A fusible link (letter K)
- Joint connector-E01 E1
- IPDM E/R harness connector E18
- Junction block connectors E44, E48
- Harness for open or short between cooling fan relay-2 and battery
- Harness for open or short between cooling fan relay-3 and battery
- Harness for open or short between cooling fan relay-2 and IPDM E/R
- Harness for open or short between cooling fan relay-3 and IPDM E/R
3.CHECK COOLING FAN RELAY OUTPUT SIGNAL CIRCUIT
- Turn ignition switch OFF.
- Disconnect IPDM E/R harness connectors.
- Check the continuity between cooling fan relay-2, -3 harness
connectors and IPDM E/R harness connector.
- Also check harness for short to ground and short to power.

4.DETECT MALFUNCTIONING PART
Check the following.
- Harness for open or short between cooling fan relay-2 and IPDM E/R
- Harness for open or short between cooling fan relay-3 and IPDM E/R
5.CHECK COOLING FAN MOTOR POWER SUPPLY CIRCUIT

- Disconnect cooling fan motor-1 harness connector.
- Check the voltage between cooling fan motor-1 harness connector
and ground.

6.DETECT MALFUNCTIONING PART
Check the following.
- 40 A fusible link (letter M)
- Harness connector E12, E203
- Harness for open or short between cooling fan motor-1 and battery
7.CHECK COOLING FAN MOTOR CIRCUIT-I
- Disconnect cooling fan motor-2 harness connector.
- Check the continuity between cooling fan relay-2, -3 harness
connectors and cooling fan motor-1, -2 harness
connectors.
- Also check harness for short to ground and short to power.

8.DETECT MALFUNCTIONING PART
Check the following.
- Joint connector-E02 E20
- Harness connector E12, E203
- Harness for open or short between cooling fan motor-1 and cooling
fan relay-2
- Harness for open or short between cooling fan motor-1 and cooling
fan relay-3
- Harness for open or short between cooling fan motor-2 and cooling
fan relay-2
- Harness for open or short between cooling fan motor-2 and cooling
fan relay-3
9.CHECK COOLING FAN MOTOR CIRCUIT-II
- Check the continuity between IPDM E/R harness connector and
cooling fan motor-1, -2 harness connector.
- Also check harness for short to ground and short to power.

10.DETECT MALFUNCTIONING PART
Check the following.
- Joint connector-E02 E20
- Harness connector E70, E305
- Harness for open or short between cooling fan motor-1 and IPDM E/R
- Harness for open or short between cooling fan motor-2 and IPDM E/R
11.CHECK COOLING FAN MOTOR CIRCUIT-III
- Check the continuity between cooling fan relay-2, -3 harness
connectors and ground.
- Also check harness for short to ground and short to power.

12.CHECK COOLING FAN MOTOR CIRCUIT-IV
- Check the continuity between cooling fan motor-2 harness connector
and ground.
- Also check harness for short to ground and short to power.

13.CHECK COOLING FAN RELAYS-2 AND -3
14.CHECK COOLING FAN MOTORS-1 AND -2
15.CHECK INTERMITTENT INCIDENT
Component Inspection (Cooling Fan Motor)
1.CHECK COOLING FAN MOTOR

- Turn ignition switch OFF.
- Disconnect cooling fan motor harness connector.
- Supply cooling fan motor terminals with battery voltage and
check operation.

Check that cooling fan speed of condition B is higher than that of A.
Component Inspection (Cooling Fan Relay)
1.CHECK COOLING FAN RELAY

- Disconnect cooling fan relays -2, -3 harness connectors.
- Check continuity between cooling fan relay -2, -3 terminals
under the following conditions.

Description
ASCD indicator lamp illuminates to indicate ASCD operation status. CRUISE is
integrated in combination
meter.
CRUISE illuminates when MAIN switch on ASCD steering switch is turned ...
Description
The electrical load signal (Headlamp switch signal, rear window defogger
switch signal, etc.) is transferred via
the CAN communication line from BCM to ECM via the IPDM E/R.
Componen ...
Other materials:
NISSAN Intelligent Key
1. Intelligent Keys (two sets)
2. Mechanical keys
3. Key number plate (one plate)
Your vehicle can only be driven with the Intelligent
Keys which are registered to your vehicle's Intelligent
Key System components.
Never leave these keys in the vehicle.
As many as four Intelligent Keys can ...
The braking distance is long
Diagnosis Procedure
CAUTION:
The stopping distance on slippery road surfaces might be longer with the ABS
operating than when
the ABS is not operating.
1.CHECK FUNCTION
Turn ignition switch OFF and disconnect ABS actuator and electric unit
(control unit) connector to deactivate
ABS. In ...
RGB (R: red) signal circuit
Description
Transmit the image displayed with AV control unit with RGB signal to the
display unit.
Diagnosis Procedure
1.CHECK CONTINUITY RGB (R: RED) SIGNAL CIRCUIT
Turn ignition switch OFF.
Disconnect display unit connector M141 and AV control unit
connector M117.
Check continu ...