DD15 Troubleshooting – Section 26.3 SPN 103/FMI 4

Section 26.3
SPN 103/FMI 4

This diagnosis is typically circuit failed low.‪

Check follows:‪

1. Disconnect the Turbo Speed Sensor (TSS).
2. Disconnect the 120–pin MCM connector.
3. Measure the resistance across pins 1 and 2 of the TSS connector.
   1. If the resistance is less than 5 Ω, repair the short between the 120–pin MCM connector wires 50 and 51. Refer to "26.3.1 Verify Repairs" .
   2. If the resistance is greater than 5 Ω, go to the next step.
4. Measure the resistance between pin 1 of the TSS harness connector and ground.
   1. If the resistance is less than 5 Ω, repair the short between pin 1 of the TSS harness connector and ground. Refer to "26.3.1 Verify Repairs" .
   2. If the resistance is greater than 5 Ω, go to the next step.
5. Measure the resistance between pin 2 of the TSS harness connector and ground.
   1. If the resistance is less than 5 Ω, repair the short between pin 2 of the TSS harness connector and ground. Refer to "26.3.1 Verify Repairs" .
   2. If the resistance is greater than 5 Ω, there should be no problem. Check by referring to section "26.3.1 Verify Repairs" .

Section 26.3.1
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.

   ENGINE EXHAUST ‪
   To avoid injury from inhaling engine exhaust, always operate the engine in a well-ventilated area. Engine exhaust is toxic.‪

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.