Page 925 of 1500
ENGINE COOLING DIAGNOSIS
ENGINE COOLING14-10
STEP 10. Measure the terminal voltage at fan control relay
connector A-10X.
(1) Disconnect fan control relay connector A-10X (remove the
fan control relay) and measure relay box side connector.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between fan control relay connector
A-10X terminal 3 and body earth.
The voltage should measure system voltage.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
(5) Connect fan control relay connector A-10X (install the fan
control relay).
Q: Is the measured voltage system voltage?
YES : Go to Step 13.
NO : Go to Step 11.
Page 926 of 1500
ENGINE COOLING DIAGNOSIS
ENGINE COOLING14-11
STEP 11. Check the ECU connector B-21, intermediate
connector A-13 and fan control relay connector A-10X.
Q: Are there connectors in good condition?
YES : Go to Step 12.
NO : Repair or replace the connector. Then go to Step 24.
Page 927 of 1500
ENGINE COOLING DIAGNOSIS
ENGINE COOLING14-12
STEP 12. Check the harness wire between intermediate
connector A-13 terminal 2 and fan control relay connector
A-10X terminal 3.
Q: Are these harness wires in good condition?
YES : An intermittent malfunction is suspected (Refer to
00-7).
NO : Repair the damaged harness wire. Then go to Step
24.
Page 928 of 1500
ENGINE COOLING DIAGNOSIS
ENGINE COOLING14-13
STEP 13. Check the continuity between fan control relay
connector A-10X and body earth.
(1) Disconnect fan control relay connector A-10X (remove the
fan control relay) and measure relay box side connector.
(2) Measure the resistance between fan control relay connector
A-10X terminal 1 and body earth.
Continuity exists.
(3) Connect fan control relay connector A-10X (install the fan
control relay).
Q: Does the continuity exists?
YES : An intermittent malfunction is suspected (Refer to
00-7).
NO : Go to Step 14.
STEP 14. Check the fan control relay connector A-10X.
Q: Is the connector in good condition?
YES : Go to Step 15.
NO : Repair the connector or replace the relay box. Then
go to Step 24.
Page 929 of 1500
ENGINE COOLING DIAGNOSIS
ENGINE COOLING14-14
STEP 15. Check the earth connector A-14.
Q: Is the connector in good condition?
YES : Go to Step 16.
NO : Repair or replace the connector. Then go to Step 24.
STEP 16. Check the harness wire between fan control relay
connector A-10X terminal 1 and body earth connector A-14
terminal 6.
Q: Is the harness wire in good condition?
YES : An intermittent malfunction is suspected (Refer to
GROUP 00 - How to use troubleshooting 00-7).
NO : Repair the damaged harness wire. Then go to Step
24.
Page 930 of 1500
ENGINE COOLING DIAGNOSIS
ENGINE COOLING14-15
STEP 17. Check the continuity between fan controller
connector A-24 and body earth.
(1) Disconnect fan controller connector A-24 and measure
wiring harness side connector.
(2) Measure the resistance between fan controller connector
A-24 terminal 1 and body earth.
Continuity exists.
(3) Connect fan controller connector A-24.
Q: Dose the continuity exists?
YES : Go to Step 20.
NO : Go to Step 18.
STEP 18. Check the fan controller connector A-24.
Q: Is the connector in good condition?
YES : Go to Step 19.
NO : Repair or replace the connector. Then go to Step 24.
Page 931 of 1500
ENGINE COOLING DIAGNOSIS
ENGINE COOLING14-16
STEP 19. Check the harness wire between fan controller
connector A-24 terminal 1 and body earth.
Q: Is the harness wire in good condition?
YES : An intermittent malfunction is suspected (Refer to
GROUP 00 - How to use troubleshooting 00-7).
NO : Repair the damaged harness wire. Then go to Step
24.
Page 932 of 1500
ENGINE COOLING DIAGNOSIS
ENGINE COOLING14-17
STEP 20. Check the fan controller connector A-24,
intermediate connector A-13 and engine-ECU connector
B-21.
Q: Are these connectors in good condition?
YES : Go to Step 21.
NO : Repair or replace the connector. Then go to Step 24.