NO.18 COOLING SYSTEM CONCERNS-RUNS COLD [ZJ, ZY]


id0103b0802400

18

COOLING SYSTEM CONCERNS—RUNS COLD

DESCRIPTION
•  The engine does not reach normal operating temperature.
POSSIBLE CAUSE
•  Condenser fan system malfunction
•  Cooling fan system malfunction
•  Thermostat malfunction
•  ECT sensor malfunction
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
Is the customer complaint "Lack of passenger compartment heat" only?
Yes
Inspect the A/C and heater system.
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
2
Does the engine speed continue at fast idle?
Yes
Go to the symptom troubleshooting "NO.9 FAST IDLE/RUNS ON".
No
Go to the next step.
3
Remove the thermostat.
Inspect the thermostat.
Is there any malfunction?
Yes
Replace the thermostat.
No
Go to the next step.
4
Perform the Cooling Fan Control System Inspection.
Does the cooling fan control system work properly?
Yes
Perform the PID/DATA Monitor and Record Procedure and access the ECT PID.
Inspect for both the ECT PID and the temperature gauge readings.
•  If the temperature gauge on the instrument cluster indicates normal range but ECT PID is not same as the temperature gauge reading:
―  Replace the ECT sensor, if necessary.
•  If the temperature gauge on the instrument cluster indicates overheating but ECT PID is normal:
―  Inspect the temperature gauge and the heat gauge unit.
―  Repair or replace the malfunctioning part according to the inspection results.
No
Repair or replace the malfunctioning part according to the inspection results.
5
Verify test results.
•  If normal, return to diagnostic index to service any additional symptoms.
•  If malfunction remains, inspect related Service information perform repair or diagnosis.
―  If vehicle repaired, troubleshooting completed.
―  If vehicle not repaired or additional diagnostic information not available, replace the PCM.