Mazda MX-6 1998, Workshop Manual

Page: 206 / 1282

TROUBLESHOOTING [ENGINE CONTROL FS]
(2) Select the “ACTIVE COMMAND” then
"OUTPUT TEST MODE” function on the NGS
tester display.
(3) Select the “ALL OFF” and verify the cooling
fan signal is OFF.
(4) If the cooling fan control signal is ON check:
• Cooling fan relay stuck in closed position.
• Short to ground circuit between cooling fan
relay and PCM.
• Short to power in circuit between cooling fan
relay.
• DTCs for ECT sensor.
• P0117, P0118, P0125, P1116, P1117.
(5) If the cooling fan is OFF, check the following.
• Short to ground circuit between A/C switch
and PCM.
• DTC for ECT sensor.
• P0117, P0118, P0125, P1116, P1117.
5. Start the engine.
6. Verify that the cooling fan is operating when
engine is hot.
7. If the cooling fan does not operate, do as follows.
(1)
Connect the
S S T s
(NGS tester) to the DLC.
(2) Select “Active Command” mode.
(3) Select “Output Test Mode”.
(4) Select “ALL ON” mode.
(5) Press “Start” .
(6) If the cooling fan operates, check the ECT
sensor DTCs.
• P0117, P0118, P0125, P1116, P1117.
(7) If the cooling fan does not operate, do as
follows.
© Select “ALL ON” . Operate cooling fan by
selecting “Start”, and verify that
operational sound is heard from the
cooling fan relay.
(D If the operational sound is heard, check
the wiring harnesses and connectors and
cooling fan motor.
(3) If operational sound is heard, check
cooling fan relay and open circuit in wiring
harnesses and connectors.
8. Turn the A/C switch and fan switch ON.
9.
Verify the cooling fan is operating.
10. If fan does not operate, check A/C system.
Condenser fan relay
1. Verify that A/C switch and fan switch are OFF.
2.
Start the engine and let it idle.
3. Verify that the condenser fan is not operating,
4. If condenser fan is operating, check:
• Condenser fan realy for stuck in closed
position.
• Short to power in circuit between condenser
fan relay and condenser fan.
• Short to ground in circuit between A/C
pressure switches and PCM.
• Short to ground circuit between condenser fan
relay and PCM terminal 17 (short circuit).
5. Turn the A/C switch and fan switch ON.
6. Verify that the condenser fan is operating and
operating sound of A/C compressor magnetic
clutch is heard.
7. Turn the A/C switch and fan switch OFF.
8. If the condenser fan does not operate but
operating sound of A/C compressor magnetic
clutch is heard, check as follows:
•
Open circuit between ignition switch and
condenser fan relay.
• Open circuit between battery and condenser
fan relay.
• Open circuit between condenser fan relay and
PCM .
• Open circuit between condenser fan relay and
condenser fan motor or fan motor ground.
• Condenser fan relay stuck to open.
• Condenser fan motor.
9.
If both condenser fan and A/C compressor do not
operate, check:
• T P V P I D .
(Refer to 01-40A THROTTLE POSITION
SENSOR INSPECTION [FS].)
• A/C system.
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