Mazda 626 - Cooling System Concerns - Runs Cold

TROUBLESHOOTING
STEP INSPECTION
RESULTS
ACTION
5 Start engine and run it at idle speed.
Turn A/C switch on.
Do cooling fan and condenser fan operate?
Yes Go to next step.
No
If cooling fan motor does not operate,
inspect for following:
• Main cooling fan relay is stuck open.
• Main cooling fan motor malfunction
• Main cooling fan motor GND open
• Open circuit between cooling fan motor and
relay
• Open circuit between cooling fan relay and
PCM terminal 47 (except for GF4A-EL
models) or 98 (for GF4A-EL models)
Open battery power circuit for cooing fan relay
If condenser fan motor does not operate,
Inspect for following:
• Condenser fan relay is stuck open.
• Condenser fan motor malfunction
• Condenser fan motor GND open
• Open circuit between condenser fan motor
and relay
• Open circuit between condenser fan relay
and PCM terminal 17 (for GF4A-EL models)
or 45 (except for GF4A-EL models)
• Open battery power circuit for condenser fan
relay
6
is drive belt okay? Yes Go to next step.
No
Replace drive belt.
7
Is there any leakage around heater unit in passen
ger compartment?
Yes
Inspect and service heater for leakage.
No
Go to next step.
8
Are there any leakage at coolant hoses and/or
radiator?
Yes Replace malfunctioning parts.
No Go to next step.
9 Cool down the engine.
Remove thermostat and inspect operation.
(See Section E)
Is thermostat okay?
Yes
Engine coolant temperature and thermostat are
okay, inspect engine block for leakage or
blockage.
No
Access ECT V PID on NGS tester.
Inspect for both ECT V and temperature gauge
readings.
If temperature gauge on instrument cluster
indicates normal range but ECT V is not same
as temperature gauge reading, inspect ECT
sensor.
If temperature gauge on instrument cluster
indicates overheating but ECT V is normal,
inspect temperature gauge and heat gauge unit.
10 Verify test results. If okay, return to diagnostic index to service any additional symptoms.
N0.17 COOLING SYSTEM CONCERNS - RUNS COLD
17
Cooling system concerns - runs cold
DESCRIPTION
• Engine takes excessive period for reaching normal operating temperature.
POSSIBLE
CAUSE
• Thermostat malfunction
• Condenser fan system malfunction
• Cooling fan system malfunction
Diagnostic Procedure
STEP INSPECTION RESULTS ACTION
1 Is customer complaint “Lack of passenger Yes Inspect A/C and heater system.
compartment heat” only?
No
Go to next step.
F1-134