TEST
ACTION
APPLICABILITY
4
Turn the ignition off.
Install a substitute relay in place of the Lift Pump Relay.
Turn the ignition on.
With the DRB, actuate the Lift Pump Relay.
Does the Lift Pump Motor cycle on and off?
All
Yes
→ Replace the Fuel Lift Pump Relay.
Perform ROAD TEST VERIFICATION - VER-2.
No
→ Go To 5
5
Turn the ignition off.
Disconnect the Lift Pump Motor harness connector.
Remove the Lift Pump Relay.
Turn the ignition on.
Measure the voltage on the Lift Pump Relay Output circuit.
Is the voltage above 1.0 volt?
All
Yes
→ Repair the Lift Pump Relay Output circuit for a short to voltage.
Perform ROAD TEST VERIFICATION - VER-2.
No
→ Go To 6
6
Turn the ignition off.
Disconnect the Lift Pump Motor harness connector.
Remove the Lift Pump Relay.
Measure the resistance between ground and the Lift Pump Relay Output circuit.
Is the resistance above 100 kohms?
All
Yes
→ Go To 7
No
→ Repair the Lift Pump Relay Output circuit for a short to ground.
Inspect the fuse and replace as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
7
Turn the ignition off.
Disconnect the Lift Pump Motor harness connector.
Remove the Lift Pump Relay.
Connect a jumper wire across Lift Pump Relay connector cavities 30 and 87.
Using a 12-volt test light connected to ground, check the Lift Pump Relay Output
circuit in the Lift Pump Motor harness connector.
Is the test light illuminated brightly?
All
Yes
→ Go To 8
No
→ Repair the Lift Pump Relay Output circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
8
Turn the ignition off.
Disconnect the Lift Pump Motor harness connector.
Using a 12-volt test light connected to 12-volts, check the Lift Pump Ground circuit.
Is the test light illuminated brightly?
All
Yes
→ Go To 9
No
→ Repair the Lift Pump Ground circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
232
DRIVEABILITY - DIESEL
*CHECKING THE FUEL/LIFT PUMP MOTOR OPERATION —
Continued