CONDITION
POSSIBLE CAUSE
CORRECTION
INADEQUATE AIR CONDITIONER
PERFORMANCE (COOLING
SYSTEM SUSPECTED)
1. Radiator and/or air conditioning
condenser is restricted, obstructed
or dirty.
1. Remove restriction and/or clean
as necessary.
2. Electric radiator fan not operating
when A/C is on.
2. Refer to appropriate Powertrain
Diagnostic Procedures manual for
operation of the DRB scan tool.
Repair as necessary.
3. Engine is overheating (heat may
be transferred from radiator to A/C
condenser). High underhood
temperature due to engine
overheating may also transfer heat
to A/C components.
3. Correct overheating condition.
Refer to this section.
INADEQUATE HEATER
PERFORMANCE.
1. Has a diagnostic trouble code
(DTC) been set?
1. Refer to On-Board Diagnostic in
EMISSION CONTROL SYSTEMS.
2. Coolant level low.
2. Refer to testing cooling system
for leaks in this section. Repair as
necessary.
3. Obstructions in heater hose
fittings at engine.
3. Remove heater hoses at both
ends and check for obstructions.
Repair as necessary.
4. Heater hose kinked.
4. Locate kinked area and repair as
necessary.
5. Water pump is not pumping
coolant to heater core. When the
engine is fully warmed up, both
heater hoses should be hot to the
touch. The water pump drive belt
may be slipping causing poor water
pump operation.
5. Refer to water pump in this
section. Repair as necessary.
HEAT ODOR
1. Various heat shields are used at
certain driveline components. One
or more of these shields may be
missing.
1. Locate missing shields and
replace or repair as necessary.
2. Is temperature gauge reading
above the normal range?
2. Refer to the previous
Temperature Gauge Reads High in
these Diagnostic Charts. Repair as
necessary.
3. Is cooling fan operating
correctly?
3. Refer to Cooling System Fan in
this section for diagnosis. Repair as
necessary.
4. Has undercoating been applied
to any unnecessary component.
4. Clean undercoating as necessary.
5. Engine may be running rich
causing the catalytic converter to
overheat.
5. Refer to appropriate Powertrain
Diagnostic Procedures manual for
operation of the DRB scan tool.
Repair as necessary.
JX
COOLING SYSTEM
7 - 11
DIAGNOSIS AND TESTING (Continued)