DDEC III/IV Single ECM Troubleshooting

Section 14.3 Troubleshooting Flash Code 14

Section 14.3
Troubleshooting Flash Code 14

The following procedure will troubleshoot Flash Code 14.‪

Section 14.3.1
Code Check

Perform the following steps to check for codes.‪

  1. Turn vehicle ignition ON.
  2. Plug in diagnostic data reader (DDR) and determine which code is logged.
    1. If codes PID 110-FMI 3 is logged, refer to "14.3.2 Coolant Temperature Sensor Check" .
    2. If codes PID 175-FMI 3 is logged, refer to "14.3.3 Oil Temperature Sensor Check" .

Section 14.3.2
Coolant Temperature Sensor Check

Perform the following steps to check the coolant temperature sensor (CTS).‪

  1. Turn vehicle ignition OFF.
  2. Disconnect CTS and install a jumper between the CTS connector sockets A and B. See Figure "Temperature Sensor Circuits" .
  3. Turn vehicle ignition ON.
  4. Read active codes.
    1. If code 110/4 or any other codes except 110/3 are logged, refer to "14.3.8 Open Line Check " .
    2. If code 110/3 is logged and any codes except code 110/4 are logged, refer to "14.3.4 Check for Signal Short to +5 Volt Line" .
    3. Click to see this graphic in a separate window

      Figure 1. Temperature Sensor Circuits

Section 14.3.3
Oil Temperature Sensor Check

Perform the following steps to check the oil temperature sensor (OTS).‪

  1. Turn vehicle ignition OFF.
  2. Disconnect OTS and install a jumper between OTS connector sockets A and B. See Figure "Temperature Sensor Circuits" .
  3. Turn ignition ON.
  4. Read active codes.
    1. If code 175/4 is logged, refer to "14.3.5 Check for Signal Short to +5 Volt Line" .
    2. If code 175/3 is logged and any codes except code 175/4 are logged, refer to "14.3.9 Open Line Check" .
    3. Click to see this graphic in a separate window

      Figure 2. Temperature Sensor Circuits

Section 14.3.4
Check for Signal Short to +5 Volt Line

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

  1. Turn ignition OFF.
  2. Remove jumper wire.
  3. Disconnect the engine harness connector at the ECM.
  4. Measure resistance between sockets P3 #133 and W1 #416 on the engine harness connector. See Figure "ECM Engine Harness Connector" .
    1. If the resistance measurement is greater than 5 Ω or open, refer to "14.3.6 Check Coolant Temperature Sensor Connectors" .
    2. If the resistance measurement is less than or equal to 5 Ω, the signal line (#133) is shorted to the engine +5 volt line (#416). Repair the short and refer to "14.3.11 Verify Repairs" .
    3. Click to see this graphic in a separate window

      Figure 3. ECM Engine Harness Connector

Section 14.3.5
Check for Signal 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. Remove jumper wire.
  3. Disconnect the engine harness connector at the ECM.
  4. Measure resistance between sockets R2 #120 and W1 #416 on the engine harness connector. See Figure "ECM Engine Harness Connector" .
    1. If the resistance measurement is greater than or equal to 5 Ω, refer to "14.3.7 Check Oil Temperature Sensor Connectors" .
    2. If the resistance measurement is less than 5 Ω, the signal line (#120) is shorted to the engine +5 volt line (#416). Repair the short and refer to "14.3.11 Verify Repairs" .

Section 14.3.6
Check Coolant Temperature Sensor Connectors

Perform the following steps to check the CTS connectors.‪

  1. Check terminals at the CTS connector (both sensor and harness side) for damage; bent, corroded and unseated pins or sockets. See Figure "Temperature Sensor Circuits" .
    1. If terminals and connectors are in good condition, replace the CTS. Refer to "14.3.11 Verify Repairs" .
    2. If the terminals and connectors are damaged, repair them. Refer to "14.3.11 Verify Repairs" .
    3. Click to see this graphic in a separate window

      Figure 4. Temperature Sensor Circuits

Section 14.3.7
Check Oil Temperature Sensor Connectors

Perform the following steps to check the OTS connectors.‪

  1. Check terminals at the OTS connector (both sensor and harness side) for damage: bent, corroded and unseated pins or sockets. See Figure "Temperature Sensor Circuits" .
    1. If terminals or connectors are damaged, repair them. Refer to "14.3.11 Verify Repairs" .
    2. If terminals and connectors are not damaged, replace the OTS. Refer to "14.3.11 Verify Repairs" .
    3. Click to see this graphic in a separate window

      Figure 5. Temperature Sensor Circuits

Section 14.3.8
Open Line Check

Perform the following steps to check for an open line.‪

  1. Turn ignition OFF.
  2. Disconnect the engine harness connector at the ECM. Leave the jumper wire between A and B of the Temperature Sensor Connector.
  3. Measure resistance between sockets P3 (#133) and Y2 (#452) on the engine harness connector. See Figure "ECM Engine Harness Connector" .
    1. If the resistance measurement is less than or equal to 5 Ω, refer to "14.3.10 Check ECM Connectors" .
    2. If the resistance measurement is greater than 5 Ω or open, the signal line (#133) or return line (#452) is open. Repair the open. Refer to "14.3.11 Verify Repairs" .
    3. Click to see this graphic in a separate window

      Figure 6. ECM Engine Harness Connector

Section 14.3.9
Open Line Check

Perform the following steps to check for an open line.‪

  1. Turn ignition OFF.
  2. Disconnect the engine harness connector at the ECM. Leave the jumper wire between A and B of the Temperature Sensor Connector.
  3. Measure resistance between sockets R2 (#120) and Y2 (#452) on the engine harness connector. See Figure "ECM Engine Harness Connector" .
    1. If the resistance measurement is less than or equal to 5 Ω, refer to "14.3.10 Check ECM Connectors" .
    2. If the resistance measurement is greater than 5 Ω or open, the signal line (#120) or return line (#452) is open. Repair the open. Refer to "14.3.11 Verify Repairs" .

Section 14.3.10
Check ECM Connectors

Perform the following steps to check the ECM connectors.‪

  1. Check terminals at the ECM engine harness connector (both ECM and harness side) for damage: bent, corroded and unseated pins or sockets. See Figure "ECM Engine Harness Connector" .
    1. If terminals or connectors are damaged, repair them. Refer to "14.3.11 Verify Repairs" .
    2. If terminals and connectors are not damaged, replace the CTS/OTS.
    3. Click to see this graphic in a separate window

      Figure 7. ECM Engine Harness Connector

Section 14.3.11
Verify Repairs

Perform the following steps to verify repairs.‪

  1. Turn vehicle ignition OFF.
  2. Reconnect all connectors.
  3. Turn vehicle ignition ON.
  4. Clear codes.
  5. Start and run the engine for eight minutes.
  6. Stop engine.
  7. Check DDR for codes.
    1. If no codes are logged, troubleshooting is complete.
    2. If code 110/3 or 175/3 and any other codes are logged, all system diagnostics are complete. Review this section to find the error. Refer to "14.3.1 Code Check" .
    3. If any codes except code 110/3 or 175/3 are logged, refer to "9.1 First Step for Diagnosing a Fault Within the DDEC System" .


DDEC III/IV Single ECM Troubleshooting Guide - 6SE497
Generated on 10-13-2008

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