DD15 SPN 84/FMI 4 Troubleshooting

SPN 84/FMI 4

This diagnostic condition is typically VSS circuit failed low.‪

Check for a short as follows:‪

1. Disconnect the VSS connector.
2. Disconnect the CPC #3 connector (21–pin).
3. Measure the resistance between pin 1 and pin 2 of the VSS harness connector.
   1. If the resistance measurement is less than 5 Ω, repair the short pin 13 and pin 14 of the CPC #3 connector (21–pin). Refer to “23.3.1.1 Verify Repairs” .
   2. If the resistance measurement is greater than 5 Ω, go to the next step.
4. Measure the resistance between pin 1 of the VSS harness connector and ground.
   1. If the resistance measurement is less than 5 Ω, repair the short to ground between pin 13 of the CPC #3 connector (21–pin) and pin 1 of the VSS harness connector. Refer to “23.3.1.1 Verify Repairs” .
   2. If the resistance measurement is greater than 5 Ω, go to the next step.
5. Measure the resistance between pin 2 of the VSS harness connector and ground.
   1. If the resistance measurement is less than 5 Ω, repair the short to ground between pin 14 of the CPC #3 connector (21–pin) and pin 2 of the VSS harness connector. Refer to “23.3.1.1 Verify Repairs” .
   2. If the resistance measurement is greater than 5 Ω, replace the VSS. Refer to “23.3.1.1 Verify Repairs” .