TEST
ACTION
APPLICABILITY
3
Turn the ignition off.
Disconnect the ECM harness connectors.
Turn the ignition switch to the Start position.
Using a 12-volt test light connected to ground, check the Fused Ignition Switch
Start/Run Output circuit in ECM C2 harness connector cavity 19.
Repeat the previous step with the ignition switch in the Run position.
Does the test light illuminate brightly in the Start and Run positions?
All
Yes
→ Go To 4
No
→ Repair the Ignition Switch Start/Run Output circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
4
Turn the ignition off.
Remove the Engine Control Relay from Fuse Block No. 1.
Using a 12-volt test light connected to 12-volts, check the Engine Control Relay
Control circuit in the Engine Control Relay connector in Fuse Block No. 1.
Turn the ignition on.
Does the test light illuminate?
All
Yes
→ Go To 5
No
→ Go To 14
5
Turn the ignition off.
Remove and inspect Fuse #17 from Fuse Block No.1.
Is the fuse open?
All
Yes
→ Go To 6
No
→ Go To 8
6
Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the EGR Valve harness connector.
Disconnect the Boost Pressure Solenoid harness connector.
Remove the Starter Relay.
Remove the Lift Pump Relay.
Install a good fuse in place of Fuse #17 in Fuse Block No.1
Connect a jumper wire between ground and the Engine Control Relay Control circuit
in ECM C2 harness connector cavity 44.
Turn the ignition on.
Remove and inspect Fuse #17 in Fuse Block No. 1.
Is the fuse open?
All
Yes
→ Repair the Engine Control relay Output circuit for a short to
ground.
Perform ROAD TEST VERIFICATION - VER-2.
No
→ Go To 7
7
NOTE: A short circuit exists in one of the following: Lift Pump Relay, Starter
Relay, EGR Valve, Boost Pressure Servo Motor or ECM.
View repair.
All
Yes
→ Using the Service Information wiring check the listed components
for short circuits. Replace the shorted component as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
236
DRIVEABILITY - DIESEL
*CHECKING THE POWER AND GROUNDS —
Continued