TEST
ACTION
APPLICABILITY
2
WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
NOTE: The conditions that set the DTC are not present at this time. The
following list may help in identifying the intermittent condition.
With the engine running at normal operating temperature, monitor the DRB
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Review the DTC When Monitored and Set Conditions. If possible, try to duplicate the
conditions under which the DTC was set.
Refer to any Technical Service Bulletins (TSB) that may apply.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Were any of the above conditions present?
All
Yes
→ Repair as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
No
→ Test Complete.
3
Turn the ignition off.
Disconnect the Glow Plug Relay harness connector.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the ECM/PCM Relay Output
circuit.
Does the test light illuminate brightly?
All
Yes
→ Go To 4
No
→ Repair the ECM/PCM Relay Output circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
4
Turn the ignition off.
Install a substitute relay in place of the Glow Plug Relay.
Perform several ignition key cycles, pausing for at least 10 seconds between each
cycle.
Turn the ignition on.
With the DRB, read ECM DTCs.
Did this DTC set again?
All
Yes
→ Go To 5
No
→ Replace the Glow Plug Relay.
Perform ROAD TEST VERIFICATION - VER-2.
5
Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Glow Plug Relay harness connector.
Remove the ECM/PCM Relay from the IPM.
Connect a jumper wire between cavity 1 and cavity 4 of the ECM/PCM Relay
connector.
Turn the ignition on.
Measure the voltage on the Glow Plug Relay Control circuit.
Is the voltage above 1.0 volt?
All
Yes
→ Repair the Glow Plug Relay Control circuit for a short to voltage.
Perform ROAD TEST VERIFICATION - VER-2.
No
→ Go To 6
75
DRIVEABILITY - DIESEL
P0380-GLOW PLUG CIRCUIT A OPEN CIRCUIT —
Continued