Section 131.2
SPN 4259/FMI 4

This diagnosis is typically injector #4, 5, or 6 spill control valve circuit has a short to ground.‪

Section 131.2.1
Short to Ground Check

Check as follows:‪

1. Disconnect the Rear Injector Harness 12–pin connector.
2. Inspect the Rear Injector Harness 12–pin connector for bent or spread pins, inspect the connector seal for damage (signs of water or oil intrusion).
   1. If the water or oil intrusion, bent or spread pins are found, repair as necessary. Refer to "131.2.1.1 Verify Repairs" .
   2. If connector shows no signs of damage, go to step 3 .
3. Measure the resistance between pin 4 on the valve cover side of the Rear Injector Harness 12–pin connector and ground. If you are using J-48671–10 , measure between injector #4 pin 3 and ground.
   1. If the resistance is greater than 3 Ω, go to step 4 .
   2. If the resistance is less than 3 Ω, go to step 6 .
4. Measure the resistance between pin 7 on the valve cover side of the Rear Injector Harness 12–pin connector and ground. If you are using J-48671–10 , measure between injector #5 pin 3 and ground.
   1. If the resistance is greater than 3 Ω, go to step 5 .
   2. If the resistance is less than 3 Ω, go to step 6 .
5. Measure the resistance between pin 11 on the valve cover side of the Rear Injector Harness 12–pin connector and ground. If you are using J-48671–10 , measure between injector #6 pin 3 and ground.
   1. If the resistance is greater than 3 Ω, go to step 13 .
   2. If the resistance is less than 3 Ω, go to step 6 .
6. Remove the upper valve cover.
7. Disconnect injector #4.
8. Measure the resistance between pin 4 on the valve cover side of the Rear Injector Harness 12–pin connector and ground. If you are using J-48671–10 , measure between injector #4 pin 3 and ground.
   1. If the resistance is greater than 3 Ω, replace injector #4. Refer to "131.2.1.1 Verify Repairs" .
   2. If the resistance is less than 3 Ω, go to step 9 .
9. Disconnect injector #5.
10. Measure the resistance between pin 7 on the valve cover side of the Rear Injector Harness 12–pin connector and ground. If you are using J-48671–10 , measure between injector #5 pin 3 and ground.
    1. If the resistance is greater than 3 Ω, replace injector #5. Refer to "131.2.1.1 Verify Repairs" .
    2. If the resistance is less than 3 Ω, go to step 11 .
11. Disconnect injector #6.
12. Measure the resistance between pin 4 on the valve cover side of the Rear Injector Harness 12–pin connector and ground. If you are using J-48671–10 , measure between injector #6 pin 3 and ground.
    1. If the resistance is greater than 3 Ω, replace the #6 injector. Refer to "131.2.1.1 Verify Repairs" .
    2. If the resistance is less than 3 Ω, replace the under valve cover injector harness. Refer to "131.2.1.1 Verify Repairs" .
13. Disconnect the 120–pin MCM connector.
14. Measure the resistance between pin 4 of the Rear Injector Harness 12–pin connector and ground.
    1. If the resistance is greater than 3 Ω, go to step 15 .
    2. If the resistance is less than 3 Ω, repair the short to ground between pin 5 of the MCM 120–pin connector and pin 4 of the Rear Injector Harness 12–pin connector. Refer to "131.2.1.1 Verify Repairs" .
15. Measure the resistance between pin 7 of the Rear Injector Harness 12–pin connector and ground.
    1. If the resistance is greater than 3 Ω, go to step 16 .
    2. If the resistance is less than 3 Ω, repair the short to ground between pin 7 of the MCM 120–pin connector and pin 7 of the Rear Injector Harness 12–pin connector. Refer to "131.2.1.1 Verify Repairs" .
16. Measure the resistance between pin 11 of the Rear Injector Harness 12–pin connector and ground.
    1. If the resistance is greater than 3 Ω, call the Detroit Diesel Customer Support Center at 313–592–5800 for MCM replacement authorization.
    2. If the resistance is less than 3 Ω, repair the short to ground between pin 9 of the MCM 120–pin connector and pin 11 of the Rear Injector Harness 12–pin connector.

Section 131.2.1.1
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.