DDEC III/IV Single ECM Troubleshooting – Section 35.3 Troubleshooting Flash Code 35

Section 35.3
Troubleshooting Flash Code 35

The following procedure will troubleshoot Flash Code 35.‪

Section 35.3.1
Multiple Code Check

Perform the following steps to check for multiple codes.‪

1. Turn vehicle ignition switch ON.
2. Plug the diagnostic data reader (DDR) into the diagnostic data link (DDL).
3. Read active codes.
   1. If code 100/3 and no other codes were logged, refer to "35.3.2 Sensor Check" .
   2. If code 100/3 and any of the following codes were logged: 73/3 or 4, 94/3 or 4, 100/4, 101/3 or 4, 102/3 or 4, 110/3 or 4, 174/3 or 4, 175/3 or 4, refer to "90.1 Description of Engine Sensor Harness" .

Section 35.3.2
Sensor Check

Perform the following steps to check the sensor.‪

1. Turn ignition switch OFF.
2. Disconnect OPS connector.
3. Turn ignition ON.
4. Start and run the engine.
5. Select engine temperature (COOLANT TEMP or OIL TEMP) on the DDR.
6. Warm up engine until engine temperature reading is greater than 60°C (140°F).
7. After warm-up, let engine run at idle.
8. Read active codes.
   1. If active code 100/3 and any other codes were logged, refer to "35.3.5 Check for Signal Short to 5 Volt" .
   2. If code 100/4 and any other codes except 100/3 were logged, refer to "35.3.3 Return Circuit Check" .

Section 35.3.3
Return Circuit Check

Perform the following steps to check the return circuit.‪

1. Turn vehicle ignition OFF.
2. Disconnect the engine harness connector at the ECM.
3. Install a jumper wire between pin A and pin B of the OPS harness connector. See Figure "Engine Harness Connector to Oil Pressure Sensor" .
4. Measure resistance between sockets P2 and Y2 on the engine harness connector.
   1. If resistance measurement is less than or equal to 5 Ω, refer to "35.3.4 Check Oil Pressure Sensor Connectors" .
   2. If resistance measurement is greater than 5 Ω, the return line (#452) is open. Repair the open and refer to "35.3.8 Verify Repairs" .
   

   Figure 1. Engine Harness Connector to Oil Pressure Sensor

Section 35.3.4
Check Oil Pressure Sensor Connectors

Perform the following steps to check the OPS connectors.‪

1. Check terminals at the OPS connectors (both the sensor and harness side) for damage: bent, corroded and unseated pins or sockets.
   1. If the terminals and connectors are damaged, repair them and refer to "35.3.8 Verify Repairs" .
   2. If the terminals and connectors are not damaged, replace the OPS. Refer to "35.3.8 Verify Repairs" .

Section 35.3.5
Check for Signal Short to 5 Volt

Perform the following steps to check for signal open.‪

1. Turn vehicle ignition OFF.
2. Disconnect the engine harness connector at the ECM.
3. Measure resistance between sockets P2 and W1 on the engine harness connector. See Figure "ECM Engine Harness Connector" .
   1. If the resistance measurement is less than or equal to 100 Ω, the signal line (#530) is shorted to the engine +5 volt line (#416). Repair the short and refer to "35.3.8 Verify Repairs" .
   2. If the resistance measurement is greater than 100 Ω, or open, refer to "35.3.6 Check for Short to Battery (+)" .
   

   Figure 2. ECM Engine Harness Connector

Section 35.3.6
Check for Short to Battery (+)

Perform the following steps to check for a short to battery (+).‪

1. Remove both fuses to the ECM.
2. Disconnect the vehicle harness and 5-way power connectors at the ECM. See Figure "ECM Vehicle Harness Connector" .
3. Measure resistance between socket P2 on the engine harness connector and socket B3 of the vehicle harness connector, and between P2 and the 5-way power harness sockets A and C.
   1. If resistance measurement is greater than 100 Ω, or open, refer to "35.3.7 Check ECM Connector" .
   2. If resistance measurement is less than or equal to 100 Ω, a short exists between sockets where less than 100 Ω resistance was read. Repair short and reinsert fuses. Refer to "35.3.8 Verify Repairs" .
   

   Figure 3. ECM Vehicle Harness Connector

Section 35.3.7
Check ECM Connector

Perform the following steps to check the ECM connector:‪

1. Inspect the terminals at the ECM connector (ECM and harness side) for damage: bent, corroded, and unseated pins or sockets.
   1. If the terminals and connector are damaged, repair both and refer to "35.3.8 Verify Repairs" .
   2. If the terminals and connector are not damaged, refer to "35.3.4 Check Oil Pressure Sensor Connectors" .

Section 35.3.8
Verify Repairs

Perform the following steps to verify repairs:‪

1. Turn ignition switch OFF.
2. Reconnect all connectors.
3. Turn ignition ON.
4. Clear codes.
5. Start and run the engine for one minute.
6. Stop engine.
7. Check codes with DDR.
   1. If no codes are logged, no further troubleshooting is required.
   2. If code 100/3 is not logged, but other codes are logged, refer to "9.1 First Step for Diagnosing a Fault Within the DDEC System" .
   3. If code 100/3 is logged, all system diagnostics are complete. Contact Detroit Diesel Technical Service.