Symptom:
*CHECKING THE FUEL HEATER OPERATION
POSSIBLE CAUSES
FUEL HEATER RELAY
FUEL HEATER RELAY OUTPUT CIRCUIT OPEN
FUEL HEATER RESISTANCE
FUSED B+ CIRCUIT OPEN
GROUND CIRCUIT OPEN
IGNITION SWITCH OUTPUT CIRCUIT OPEN
RELAY GROUND CIRCUIT OPEN
TEST
ACTION
APPLICABILITY
1
Turn the ignition off.
Disconnect the Fuel Heater harness connector.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the Fuel Heater Relay Output
circuit at the Fuel Heater harness connector.
Is the test light on?
All
Yes
→
Go To
2
No
→
Go To
4
2
Turn the ignition off.
Disconnect the Fuel Heater harness connector.
Turn the ignition on.
Using a 12-volt test light connected to 12-volts, check the Ground circuit at the Fuel
Heater harness connector.
Is the test light on?
All
Yes
→
Go To
3
No
→
Repair the Ground circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
3
Turn the ignition off.
Disconnect the Fuel Heater harness connector.
Turn the ignition on.
With the DRB, read the Fuel Temperature Sensor.
NOTE: The Fuel temperature must be below 4.5°C (40°F).
Measure the resistance of the Fuel Heater.
Is the resistance between 0.7 and 2.0 ohms?
All
Yes
→
Test Complete.
No
→
Replace the Fuel Heater.
Perform ROAD TEST VERIFICATION - VER-2.
171
DRIVEABILITY - DIESEL