DDEC III/IV Single ECM Troubleshooting – Section 33.3 Troubleshooting Flash Code 33

Section 33.3
Troubleshooting Flash Code 33

The following procedure will troubleshoot Flash Code 33.‪

Section 33.3.1
Multiple Code Check

Perform the following steps to check for multiple codes.‪

1. Plug the diagnostic data reader (DDR) into the diagnostic data link (DDL).
2. Turn vehicle ignition switch ON.
3. Read active codes.
   1. If code 102/3 and no other codes were logged, refer to "33.3.2 Sensor Check" .
   2. If any of the following codes are also present: 72/3 or 4, 73/3 or 4, 94/3 or 4, 100/3 or 4, 101/3 or 4, 110/3 or 4, 174/3 or 4, 175/3 or 4, refer to "90.1 Description of Engine Sensor Harness" .

Section 33.3.2
Sensor Check

Perform the following steps to check the sensor.‪

1. Turn vehicle ignition OFF.
2. Disconnect the TBS connector. See Figure "Turbo Boost Sensor" .
3. Start and run the engine at idle.
4. Read active codes logged.
   1. If active code 102/3 and any other codes are logged, refer to "33.3.5 Check for Short to +5 Volt Line" .
   2. If active code 102/4 and any other codes except 102/3 are logged, refer to "33.3.4 Check Turbo Boost Sensor Connectors" .
   

   Figure 1. Turbo Boost Sensor

Section 33.3.3
Return Circuit Check

Perform the following steps to check the return circuit.‪

1. Turn ignition switch OFF.
2. Install a jumper wire between pin A and pin B of the TBS harness connector. See Figure "Turbo Boost Sensor" .
3. Disconnect the engine harness connector at the ECM. See Figure "ECM Engine Harness Connector" .
4. Measure resistance between sockets P1 and Y2 on the engine harness connector.
   1. If resistance measurement is less than or equal to 5 Ω, refer to "33.3.4 Check Turbo Boost Sensor Connectors" .
   2. If resistance measurement is greater than 5 Ω, the return line #452 is open. Repair the open. Refer to "33.3.8 Verify Repairs" .
   

   Figure 2. Turbo Boost Sensor

   

   Figure 3. ECM Engine Harness Connector

Section 33.3.4
Check Turbo Boost Sensor Connectors

Perform the following steps to check the TBS connectors.‪

1. Check terminals at the TBS connector (both sensor and harness side) for damage: bent, corroded, and unseated pins or sockets. See Figure "Turbo Boost Sensor" .
   1. If the terminals and connectors are damaged, repair them. Refer to "33.3.8 Verify Repairs" .
   2. If the terminals and connectors are not damaged, replace the TBS. Refer to "33.3.8 Verify Repairs" .
   

   Figure 4. Turbo Boost Sensor

Section 33.3.5
Check for Short to +5 Volt Line

Perform the following steps to check for a short to the +5 volt line:‪

1. Turn vehicle ignition OFF.
2. Disconnect engine harness connector from the ECM.
3. Measure resistance between sockets P1 and W1 on the engine harness connector. See Figure "ECM Engine Harness Connector" .
   1. If measured resistance is less than or equal to 10,000 Ω, the signal line #432 is shorted to the engine +5 volt line #416. Repair short. Refer to "33.3.8 Verify Repairs" .
   2. If measured resistance is greater than 10,000 Ω, or open, refer to "33.3.6 Check for Short to Battery" .
   

   Figure 5. ECM Engine Harness Connector

Section 33.3.6
Check for Short to Battery

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

1. Remove both fuses to the ECM.
2. Disconnect the vehicle harness and 5-way power connector harness at the ECM. See Figure "5-Way ECM Power Connector" .
3. Measure resistance between sockets P1 of the engine harness connector and B3 on the vehicle harness connector.
4. Measure resistance between socket P1 on the engine harness connector and the 5-way power harness connector sockets A and C.
   1. If the resistance measurement is less than or equal to 100 Ω, a short exists between sockets where the measurement was taken. Repair short and reinsert fuses, or reset breakers. Refer to "33.3.8 Verify Repairs" .
   2. If the resistance measurement is greater than 100 Ω, or open, refer to "33.3.7 Check ECM Connectors" .
   

   Figure 6. 5-Way ECM Power Connector

Section 33.3.7
Check ECM Connectors

Perform the following steps to check the ECM connectors.‪

1. Check terminals at the ECM engine harness connector (both the ECM and harness side) for damage: bent, corroded, and unseated pins or sockets.
   1. If terminals and connectors are damaged, repair both. Refer to "33.3.8 Verify Repairs" .
   2. If terminals and connectors are not damaged, reprogram the ECM. Refer to "33.3.8 Verify Repairs" .

Section 33.3.8
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 DDR for codes.
   1. If no codes are logged, troubleshooting is complete.
   2. If code 102/3 is not logged, and other codes are logged, refer to "9.1 First Step for Diagnosing a Fault Within the DDEC System" .
   3. If code 102/3 is logged, and other codes are logged, refer to "33.3.1 Multiple Code Check" .