DTC Chart

PCM DTC CHART

DTC	Description	Action
P0217	Engine Coolant Overtemperature Condition	GO to PINPOINT TEST B .
P1285	Cylinder Head Overtemperature Condition	GO to PINPOINT TEST B .
P1299	Cylinder Head Overtemperature Protection Active	GO to PINPOINT TEST B .
P0125	Insufficient Coolant Temp For Closed Loop Fuel Control	GO to PINPOINT TEST C .
P0128	Coolant Thermostat (Coolant Temp Below Thermostat Regulating Temperature)	GO to PINPOINT TEST C .
P0480 P0481 P0482	Fan 1, 2 or 3 Control Circuit, Respectively	REFER to the INTRODUCTION - GASOLINE MODELS article.
All Other PCM DTCs	-	REFER to ELECTRONIC ENGINE CONTROLS article.

SYMPTOM CHART

Condition	Possible Sources	Action
Loss of coolant	Coolant hoses or tubes Hose clamps Coolant pump O-ring seal Thermostat housing gasket Thermostat housing Radiator Coolant expansion tank Pressure relief cap Coolant pump leaking from weep hole Heater core Engine gaskets (may leak internally or externally) Cylinder block core plugs Cylinder head core plugs Block heater (if equipped)	GO to PINPOINT TEST A .
The engine overheats	Low coolant level External engine coolant leak Airlock in system Pressure relief cap installation Restricted airflow through the A/C condenser/radiator Internal engine coolant leak Coolant condition/concentration Accessory drive components Non-OEM engine enhancement components Electric cooling fan Radiator Thermostat Engine Coolant Temperature (ECT) (gauge) Cylinder Head Temperature (CHT) sensor Heater core Coolant pump Coolant flow restriction	GO to PINPOINT TEST B .
The engine does not reach normal operating temperature	Low coolant level Thermostat Electric cooling fan always on ECT (gauge) CHT sensor	GO to PINPOINT TEST C .
The block heater does not operate correctly	Block heater power cable	CHECK continuity in all 3 power cable circuits. If any circuit measures more than 5 ohms, INSTALL a new power cable.
The block heater does not operate correctly	Block heater	CHECK the resistance of the block heater. If the resistance does not measure between 12.5 and 17 ohms, INSTALL a new block heater.
The electric cooling fan is inoperative in one or more speeds or does not operate correctly	Wiring Relays Fuses Fan Control (FC) module Cooling fan motor Cooling fan resistor	REFER to the INTRODUCTION - GASOLINE MODELS article.
The electric cooling fan stays on all the time	Wiring Relays FC module	REFER to the INTRODUCTION - GASOLINE MODELS article.
Noisy electric cooling fan operation	Foreign material contamination Fan motor	REMOVE the foreign material from the cooling fan and shroud. TEST the system for normal operation. If still noisy, INSTALL a new cooling fan assembly.
Noisy electric cooling fan operation	Fan blade detached from fan motor	INSTALL a new cooling fan assembly.