TEST
ACTION
APPLICABILITY
4
Turn the ignition off.
Install a substitute relay in place of the Fuel Heater Relay.
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.
Is the test light on?
All
Yes
→
Replace the initial Fuel Heater Relay.
Perform ROAD TEST VERIFICATION - VER-2.
No
→
Go To
5
5
Turn the ignition off.
Remove the Fuel Heater Relay.
Using a 12-volt test light connected to ground, check the Fused B+ circuit.
Is the test light on?
All
Yes
→
Go To
6
No
→
Repair the Fused B+ circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
6
Turn the ignition off.
Remove the Fuel Heater Relay.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the Ignition Switch Output
circuit.
Is the test light on?
All
Yes
→
Go To
7
No
→
Repair the Ignition Switch Output circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
7
Turn the ignition off.
Remove the Fuel Heater Relay.
Turn the ignition on.
Using a 12-volt test light connected to 12-volts, check the Ground circuit at the Fuel
Heater Relay connector.
Is the test light on?
All
Yes
→
Repair the Fuel Heater Relay Output circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
No
→
Repair the Ground circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
184
DRIVEABILITY - DIESEL
*CHECKING THE FUEL HEATER OPERATION —
Continued