Series 60 DDEC V Troubleshooting – Section 30.2 Troubleshooting Flash Code 24, PID 174/FMI 4

Section 30.2
Troubleshooting Flash Code 24, PID 174/FMI 4

This diagnostic condition is typically sensor signal circuit is shorted to sensor return circuit or to ground.‪

The following procedure will troubleshoot Flash Code 24.‪

Section 30.2.1
Multiple Code Check

Perform the following steps to check for multiple codes.‪

1. Turn ignition ON.
2. Plug in diagnostic tool.
3. Read active codes.
   1. If active code p 174/4 and no other active codes are logged, refer to "30.2.2 Sensor Check" .
   2. If any or all of the following codes are logged, p 110/3, p 175/3, p 174/3, or p 102/3, refer to "80.1 Troubleshooting the Vehicle Interface Harness +5 Volt Supply" .
   3. If codes other than the above are logged, refer to "30.2.2 Sensor Check" .

Section 30.2.2
Sensor Check

Perform the following steps to check the sensor:‪

1. Turn ignition OFF.
2. Disconnect the FTS/SFT Sensor connector.
3. Start and run engine for eight minutes.
4. Read active codes with engine still running.
   1. If code p 174/4 and any other codes are logged, refer to "30.2.3 Check Fuel Temperature Sensor Connectors" .
   2. If code p 174/3 and any other codes except p 174/4 are logged, refer to "30.2.4 Check for Short" .

Section 30.2.3
Check Fuel Temperature Sensor Connectors

Check terminals at the FTS/SFT Sensor connector (both sensor and harness side) for bent, corroded, and unseated pins or sockets. See Figure "Supply Fuel Temperature Sensor" .‪

Figure 1. Supply Fuel Temperature Sensor

If terminals and connectors are damaged, repair them. Refer to "30.2.5.1 Verify Repairs" .‪

If terminals and connectors are not damaged, replace the FTS/SFT Sensor. Refer to "30.2.5.1 Verify Repairs" .‪

Section 30.2.4
Check for Short

Perform the following steps to check for a short:‪

1. Turn ignition OFF.
2. Disconnect the engine harness connector at the ECM/ECU.
3. Measure resistance between sockets E-9 and E-14 on the engine harness connector. See Figure "ECM/ECU Engine Harness Connector" .
4. Measure resistance between socket E-9 and a good ground (battery ground and chassis ground).
   1. If resistance between sockets E-9 and E-14, or E9 and battery ground, is less than or equal to 10,000 Ω, the signal line (E-9) is shorted to the return line (E-14) or battery ground. Repair short. Refer to "30.2.5.1 Verify Repairs" .
   2. If resistance between sockets E-9 and E-14 is greater than 10,000 Ω or open, and resistance between socket 2 and a good ground is greater than 10,000 Ω or open, refer to "30.2.5 Check ECM/ECU Connectors" .
   

   Figure 2. ECM/ECU Engine Harness Connector

Section 30.2.5
Check ECM/ECU Connectors

Check terminals at the ECM/ECU harness connector (both ECM/ECU and harness side) for bent, corroded, and unseated pins or sockets. See Figure "ECM/ECU Engine Harness Connector" .‪

If terminals and connectors are damaged, repair them. Refer to "30.2.5.1 Verify Repairs" .‪

If terminals and connectors are not damaged, contact Detroit Diesel Customer Support Center (313–592–5800). Refer to "30.2.5.1 Verify Repairs" .‪

Section 30.2.5.1
Verify Repairs

‪

Perform the following steps to verify repairs:‪

1. Turn ignition OFF.
2. Reconnect all connectors.
3. Turn ignition ON.
4. Clear codes with diagnostic tool.
5. Start and run the engine for eight minutes.
6. Stop engine.
7. Read active codes.
   1. If no codes are logged, troubleshooting is complete.
   2. If code p 174/4 and any other codes are logged, all system diagnostics are complete. Review this section from the first step to find the error. Refer to "30.2.1 Multiple Code Check" .
   3. If code p 174/4 is not logged, but other codes are logged, refer to "18.3 First Step for Diagnosing a Fault Within the DDEC System" .