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NO.18 COOLING SYSTEM CONCERNS-RUNS COLD [L3]

BME010300000W20

18 | COOLING SYSTEM CONCERNS -RUNS COLD
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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
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1 | Is customer complaint "Lack of passenger compartment heat" only? | Yes | Inspect A/C and heater system.
No | Go to next step.
2 | Does engine speed continue at fast idle? | Yes | Go to symptom troubleshooting "No.9 Fast idle/runs on".
No | Go to next step.
3 | Remove thermostat and inspect operation. (See THERMOSTAT REMOVAL/INSTALLATION [L3].) (See THERMOSTAT INSPECTION.) Is thermostat okay? | Yes | Go to next step.
No | Replace thermostat.
4 | Inspect cooling fan control system operation. (See Cooling Fan Motors Operation Inspection.) Does cooling fan control system work properly? | Yes | Access ECT PID. Inspect for both ECT PID and temperature gauge on instrument cluster readings. If temperature gauge on instrument cluster indicates normal range but ECT PID is not same as temperature gauge reading, inspect ECT sensor. If temperature gauge on instrument cluster indicates cold range but ECT PID is normal, inspect temperature gauge and heat gauge unit.
No | Repair or replace malfunctioning part.
5 | Verify test results. • If okay, return to diagnostic index to service any additional symptoms. • If malfunction remains, replace PCM.