This diagnosis is typically injector #1, 2, or 3 needle control valve circuit is shorted to ground.
95.2.1 Short to Ground Check
Check as follows:
1. Disconnect the Front Injector Harness 12–pin connector.
2. Inspect the Front Injector Harness 12–pin connector for bent or spread pins, inspect the
connector seal for damage (signs of water or oil intrusion).
[a] If the water or oil intrusion, bent or spread pins are found, repair as necessary.
[b] If connector shows no signs of damage, go to step 3.
3. Measure the resistance between pin 10 on the valve cover side of the Front Injector
Harness 12–pin connector and ground. If you are using J-48671–10, measure between
injector #1 pin 1 and ground.
[a] If the resistance is greater than 3 Ω, go to step 11.
[b] If the resistance is less than 3 Ω, go to step 4.
4. Remove the valve cover.
5. Disconnect injector #1.
6. Measure the resistance between pin 10 on the valve cover side of the Front Injector
Harness 12–pin connector and ground. If you are using J-48671–10, measure between
injector #1 pin 1 and ground.
[a] If the resistance is greater than 3 Ω, replace the #1 injector. Refer to section 95.2.1.1.
[b] If the resistance is less than 3 Ω, go to step 7.
7. Disconnect injector #2.
8. Measure the resistance between pin 10 of the valve cover side on the Front Injector
Harness 12–pin connector and ground. If you are using J-48671–10, measure between
injector #2 pin 1 and ground.
[a] If the resistance is greater than 3 Ω, replace the #2 injector. Refer to section 95.2.1.1.
[b] If the resistance is less than 3 Ω, go to step 9.
9. Disconnect injector #3.
10. Measure the resistance between pin 10 on the valve cover side of the Front Injector
Harness 12–pin connector and ground.
[a] If the resistance is greater than 3 Ω, replace the #3 injector. Refer to section 95.2.1.1.
[b] If the resistance is less than 3 Ω, replace the under valve cover Injector Harness.
Refer to section 95.2.1.1.
11. Disconnect the 120–pin MCM connector.
12. Measure the resistance between pin 10 on the Front Injector Harness 12–pin connector
and ground. If you are using J-48671–10, measure between injector #3 pin 1 and ground.
[a] If the resistance is less than 3 Ω, repair the short to ground between pin 11 of the
MCM 120–pin connector and pin 10 of the Front Injector Harness 12–pin connector.
Refer to section 95.2.1.1.
[b] If the resistance is greater than 3 Ω, call the Detroit Diesel Customer Support Center
at 313–592–5800 for MCM replacement authorization.
95.2.1.1 Verify Repairs
Verify repairs as follows:
1. Turn ignition OFF.
2. Reconnect any electrical connections that were disconnected to perform the diagnosis.
3. Clear codes with DDDL 7.0 or latest version.
4. Start and bring engine up to operating temperature (over 140°F/60°C).
5. Verify operation is satisfactory and no warning lamps illuminate. If warning lamps
illuminate, troubleshoot the codes. If assistance is required, call the Detroit Diesel
Customer Support Center at 313–592–5800.
