82.1 SPN 1072/FMI 4
This fault code indicates that the Jake Brake Stage 1 circuit failed low.
82.1.1
Short to Ground Check
Check as follows:
1. Disconnect the front injector valve cover harness.
2. Measure resistance between pins 7 and ground on the front injector valve cover harness
connector. If you are using J-48671–10, measure either rear Jake pin and ground.
[a] If the resistance is greater than 15 Ω, repair short to ground between pin 7 of the front
injector valve cover harness connector and pin 60 of the 120–pin MCM connector.
Refer to section 82.1.1.1.
[b] If the resistance is less than 5 Ω, go to step 3.
3. Remove the upper valve cover.
4. Disconnect the rear Jake Brake harness.
5. Measure resistance between either terminal on the Jake Brake solenoid and ground.
[a] If the resistance is less than 5 ohms, replace the Jake Brake solenoid. Refer to section
82.1.1.1.
[b] If the resistance is greater than 5 Ω, repair the short to ground between pins 7 and 8 of
the front injector valve cover harness and the Jake Brake solenoid. Refer to section
82.1.1.1.
82.2 SPN 1072/FMI 5
This fault code indicates that the Jake Brake Stage 1 circuit failed open.
82.2.1
Open Circuit Check
Check as follows:
1. Check for multiple codes.
[a] If SPN 647/5, SPN 1071/5 and SPN 1072/5 are active repair the open in between pin
91 of the 120–pin MCM connector and the rear Jake Brake and fan control solenoids.
Refer to section 82.2.1.1.
[b] If only SPN 1072/5 is active, go to step 2.
2. Disconnect the front injector valve cover harness.
3. Measure the resistance between pin 7 and 8 on the front injector valve cover harness
connector. If you are using J-48671–10, measure across the rear Jake pins.
[a] If the resistance is less than 15 Ω, repair the open between pin 7 of the front injector
valve cover harness connector and pin 66 of the 120–pin MCM connector.
[b] If the resistance is greater than 15 Ω, go to step 4.
4. Remove the valve cover.
5. Measure the resistance across the Jake Brake solenoid.
[a] If the resistance is greater than 15 Ω, replace the Jake Brake solenoid. Refer to section
82.2.1.1.
[b] If the resistance is less than 15 Ω, repair the open between pins 7 and 8 of the front
injector valve cover harness connector and the Jake Brake solenoid. Refer to section
82.2.1.1.
