DDEC III/IV Single ECM Troubleshooting

Section 22.3 Troubleshooting Flash Code 22

Section 22.3
Troubleshooting Flash Code 22

The following procedure will troubleshoot Flash Code 22. ‪

Section 22.3.1
Multiple Code Check

Perform the following steps to check for multiple codes.‪

  1. Turn ignition ON.
  2. Plug in DDR.
  3. Read active codes.
    1. If active code 91/4 and no other active codes are logged, refer to "22.3.2 Check for Device" .
    2. If code 91/4 and any or all of the following codes are logged, 91/3, 187/4, or 100/4, refer to "91.2 Troubleshooting Vehicle Harness +5 Volt Supply" .
    3. If codes other than the above are logged, refer to "9.1 First Step for Diagnosing a Fault Within the DDEC System" .

Section 22.3.2
Check for Device

Perform the following steps to check for device.‪

  1. If there is a throttle (LSG) wired to use the 417 (LSG) circuit, refer to "22.3.3 Sensor Check" .
  2. If there is no throttle (LSG) wired to use the 417 (LSG) circuit, contact Detroit Diesel Technical Service, for possible change to the calibration.
    1. If required, reprogram the ECM after the mainframe is changed and refer to "22.3.15 Verify Repairs" .

Section 22.3.3
Sensor Check

Perform the following steps to check the sensor:‪

  1. Turn ignition OFF.
  2. Disconnect the TPS connector.
  3. Install a jumper wire between sockets B (signal #417) and C (5V supply #916); see Figure "Throttle Position Sensor" .
  4. Turn ignition ON.
  5. Read active codes.
    1. If code 91/4 and any other codes are logged, refer to "22.3.7 Check for +5 Volts" .
    2. If code 91/3 and any other codes are logged, refer to "22.3.4 Check Throttle Position Sensor Adjustment" .
    3. Click to see this graphic in a separate window

      Figure 1. Throttle Position Sensor

Section 22.3.4
Check Throttle Position Sensor Adjustment

Perform the following steps to check the TPS adjustment:‪

  1. Remove jumper and reconnect TPS.
  2. Hook DDR to the DDL connector and select TPS - Counts.
  3. Read Throttle Counts at both no throttle and full throttle positions. Take several readings.
    1. If at any time counts go lower than 49 counts, refer to "22.3.5 Attempt Throttle Position Sensor Adjustment" .
    2. If counts never go lower than 49 counts, refer to "22.3.6 Check Throttle Position Sensor Connectors" .

Section 22.3.5
Attempt Throttle Position Sensor Adjustment

Perform the following steps to attempt a TPS adjustment:‪

  1. Check for pedal or linkage interferences.
  2. Loosen the TPS screws and attempt to adjust for the correct throttle reading (normal range - 64-205 counts). Do not attempt to adjust by bending the pedal mechanism.
  3. Recheck counts at idle and at full throttle.
    1. If the throttle count has been corrected, refer to "22.3.15 Verify Repairs" .
    2. If the problem could not be corrected, refer to "22.3.6 Check Throttle Position Sensor Connectors" .

Section 22.3.6
Check Throttle Position Sensor Connectors

Perform the following steps to check the TPS connectors:‪

  1. Check terminals at the TPS connector (both sensor and harness side) for bent, corroded, and unseated pins or sockets.
    1. If the terminals or the connectors are damaged, repair them. Refer to "22.3.15 Verify Repairs" .
    2. If the terminals and connectors are not damaged, replace the TPS and refer to "22.3.15 Verify Repairs" .

Section 22.3.7
Check for +5 Volts

Perform the following steps to check for +5 volts:‪

  1. Remove jumper wire.
  2. Turn ignition ON.
  3. Measure voltage on TPS harness connector, socket C (5V supply #916) (red lead) to socket A (return #952) (black lead).
    1. If measured voltage is greater than 6 volts, refer to "22.3.13 Check for Short to Battery +" .
    2. If measured voltage is less than 4 volts, refer to "22.3.11 Check for Short" .
    3. If measured voltage is between 4 and 6 volts, refer to "22.3.8 Check for Short" .

Section 22.3.8
Check for Short

Perform the following steps to check for a short:‪

  1. Turn ignition OFF.
  2. Disconnect the vehicle harness connector at the ECM.
  3. Measure resistance between sockets A (return #952) and B (signal #417) at the TPS harness connector. See Figure "Throttle Position Sensor" .
  4. Measure resistance between socket B (signal #417) and a good ground (battery ground and chassis ground).
    1. If resistance measurement is less than or equal to 100 Ω, the signal line #417 is shorted to the return line #952 or battery ground. Repair short. Refer to "22.3.15 Verify Repairs" .
    2. If resistance measurement on both readings is greater than 100 Ω or open, refer to "22.3.9 Check for Signal Open" .
    3. Click to see this graphic in a separate window

      Figure 2. Throttle Position Sensor

Section 22.3.9
Check for Signal Open

Perform the following steps to check for signal open:‪

  1. Install a jumper wire between sockets A (return #952) and B (signal #417) of the TPS harness connector.
  2. Measure resistance between sockets D2 and C3 on the vehicle connector.
    1. If the resistance is less than or equal to 5 Ω, refer to "22.3.10 Check ECM Connectors" .
    2. If the resistance is greater than 5 Ω or open, the signal line (#417) or return line (#952) are open, repair the open. Refer to "22.3.15 Verify Repairs" .

Section 22.3.10
Check ECM Connectors

Perform the following steps to check the ECM connectors:‪

  1. Check terminals at the ECM harness connector (both ECM and harness side) for bent, corroded, and unseated pins or sockets. See Figure "ECM Vehicle Harness Connector" .
    1. If terminals and connectors are damaged, repair them. Refer to "22.3.15 Verify Repairs" .
    2. If terminals and connectors are not damaged, call Detroit Diesel Technical Service for assistance.
    3. Click to see this graphic in a separate window

      Figure 3. ECM Vehicle Harness Connector

Section 22.3.11
Check for Short

Perform the following steps to check for a short.‪

  1. Turn ignition OFF.
  2. Disconnect the vehicle harness connector at the ECM.
  3. Measure resistance between sockets A (return #952) and C (5V #916) on the TPS harness connector. See Figure "ECM Vehicle Harness Connector" .
    1. If resistance between sockets A and C is greater than 1,000 Ω or open, refer to "22.3.12 Check for Open +5 Volt Line" .
    2. If resistance between sockets A and C is less than or equal to 1,000 Ω, the 5V wire (#916) is shorted to the return (#952). Repair the short and refer to "22.3.15 Verify Repairs" .
    3. Click to see this graphic in a separate window

      Figure 4. ECM Vehicle Harness Connector

Section 22.3.12
Check for Open +5 Volt Line

Perform the following steps to check for an open +5 volt line:‪

  1. Install a jumper wire between sockets A (return #952) and C (5V #916) on the TPS harness connector.
  2. Measure resistance between sockets A3 and C3 on the vehicle harness connector. See Figure "Throttle Position Sensor" .
    1. If resistance between sockets A3 and C3 is less than or equal to 5 Ω, refer to "22.3.10 Check ECM Connectors" .
    2. If resistance between sockets A3 and C3 is greater than or equal to 5 Ω or open, the vehicle +5 volt line (#916) is open. Repair the open. Refer to "22.3.15 Verify Repairs" .
    3. Click to see this graphic in a separate window

      Figure 5. Throttle Position Sensor

Section 22.3.13
Check for Short to Battery +

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

  1. Turn ignition OFF.
  2. Remove both fuses to ECM.
  3. Disconnect the 5-way power connector at the ECM.
  4. Measure resistance between socket D2 on the vehicle harness connector and the 5-way power connector sockets A and C. See Figure "ECM Vehicle Harness Connector" .
    1. If measured resistance is greater than 100 Ω or open, refer to "22.3.14 Check for Outside DDEC Battery +" .
    2. If measured resistance is less than or equal to 100 Ω, a short exists between sockets where resistance was measured. Repair short and reinsert fuses; refer to "22.3.15 Verify Repairs" .
    3. Click to see this graphic in a separate window

      Figure 6. ECM Vehicle Harness Connector

Section 22.3.14
Check for Outside DDEC Battery +

Perform the following steps to check for outside DDEC battery +:‪

  1. Turn ignition OFF.
  2. Remove ECM 5-pin power connector.
  3. Remove ECM vehicle harness connector.
  4. Turn ignition ON.
  5. Measure voltage A3 (red lead) to battery ground.
  6. Measure voltage C3 (red lead) to battery ground.
    1. If measured voltage is less than 0.2 volts, refer to "22.3.10 Check ECM Connectors" .
    2. If measured voltage is greater than 0.2 volts, outside power is spliced/shorted into either line #952 or line #916. Remove the splice/short. Refer to "22.3.15 Verify Repairs" .

Section 22.3.15
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 DDR.
  5. Start and run the engine for one minute at all throttle positions.
  6. Stop engine.
  7. Read active codes.
    1. If no codes are logged, troubleshooting is complete.
    2. If code 91/4 and any other codes are logged, all system diagnostics are complete. Review this section from the first step to find the error. Refer to "22.3.1 Multiple Code Check" .
    3. If code 91/4 is not logged, but other codes 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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