TEST
ACTION
APPLICABILITY
8
Turn the ignition on.
With the DRBIII
t, read DTCs.
Is the Good Trip Counter displayed and equal to zero for P0351?
4.0L MPI I-6
Yes
→
Go To
9
No
→
Go To
15
9
Turn the ignition off.
Disconnect the coil rail harness connector.
Note: The following resistance measurement should be taken at 70-80
degrees F.
Measure the primary resistance of the coil rail.
Is the resistance between 0.6 and 0.9 ohms?
4.0L MPI I-6
Yes
→
Go To
10
No
→
Replace the coil rail.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
10
Turn the ignition off.
Disconnect the coil rail harness connector.
Turn the ignition on.
With the DRBIII
t, actuate the generator field.
Using a 12-volt test light connected to ground, check the ASD relay output circuit at
the coil rail harness connector.
Does the test light illuminate brightly?
4.0L MPI I-6
Yes
→
Go To
11
No
→
Repair the open/high resistance in the ASD relay output circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
Stop All Actuations
11
Turn the ignition off.
Disconnect the coil rail harness connector.
Connect one end of a 12 volt test light to a good 12 volt source (B+).
Warning: Keep clear of the engine’s moving/rotating parts.
Check the ignition coil no. 1 driver circuit, with the other end of the test light, while
cranking the engine.
Does the test light blink/flicker?
4.0L MPI I-6
Yes
→
Test Complete.
No
→
Go To
12
12
Turn the ignition off.
Disconnect the coil rail harness connector.
Disconnect the PCM harness connector(s).
Measure the resistance of the ignition coil no. 1 driver circuit from the ignition coil
connector to the PCM connector.
Is the resistance below 5.0 ohms?
4.0L MPI I-6
Yes
→
Go To
13
No
→
Repair the open ignition coil no. 1 driver circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
145
DRIVEABILITY - GAS
P0351-IGNITION COIL #1 PRIMARY CIRCUIT —
Continued