DDEC III/IV Single ECM Troubleshooting

Section 29.3 Troubleshooting Flash Code 29

Section 29.3
Troubleshooting Flash Code 29

The following procedures will troubleshoot Flash Code 29: ‪

Note: This sensor is wired via the 10–pin connector. See the wiring diagram; see Figure "Connectors" .

Click to see this graphic in a separate window

Figure 1. Connectors

Section 29.3.1
Check for Codes

Perform the following steps to check for codes: ‪

  1. Turn ignition ON.
  2. Start and run engine for six minutes.
  3. Check DDR for codes.
    1. If any code other than p 351/4 or p 404/4 are logged, troubleshoot that code first.
    2. If code p 351/4 is logged, refer to "29.3.2 Check Sensor" .
    3. If code p 404/4 is logged, refer to "29.3.5 Check for Short" .

Section 29.3.2
Check Sensor

Perform the following steps to check the TCI connector.‪

  1. Unplug the connector at the TCI/RH (relative humidity sensor).
  2. Measure resistance between cavity 4 and cavity 1.
    1. If measured resistance is greater than 5 Ω, refer to "29.3.4 Check Connector Corrosion" . See Figure "ECM Engine Harness Connector " .
    2. Click to see this graphic in a separate window

      Figure 2. ECM Engine Harness Connector

    3. If measured resistance is less than 5 Ω, #905 is shorted to #452. Repair the short and test.

Section 29.3.3
Check for Open

Perform the following steps to check for short:‪

  1. Unplug the engine sensor harness.
  2. Measure resistance between cavity M1 and W1. See Figure "ECM Engine Harness Connector " .
    1. If resistance is less than 1.0 K Ω, wire #416 is shorted to #905. Repair and test.
    2. If resistance is equal to 1.1 K – 1.9 K Ω, refer to "29.3.4 Check Connector Corrosion" .
    3. If resistance is greater than 2.0 K Ω, wire #416 or #905 is open or the resistor has failed. Replace the engine harness and test.

Section 29.3.4
Check Connector Corrosion

Perform the following steps to check for corrosion at the 4–pin, 10–pin interface and 30–pin connectors.‪

  1. If corroded, clean corrosion from the terminals or replace the terminals. Test.
  2. If terminals are clean, without corrosion, replace the RH/TCI. Test.

Section 29.3.5
Check for Short

Perform the following steps to check the turbo compressor outlet (TCO) connector. ‪

  1. Unplug TCO connector.
  2. Measure resistance between cavity 1 and cavity 2 of connector.
    1. If measured resistance is greater than 5 Ω, refer to "29.3.6 Check for Failed Resistor" .
      Click to see this graphic in a separate window

      Figure 3. Turbo Compressor Outlet Temperature Circuit

    2. If measured resistance is less than 5 Ω, #906 is shorted to #452. Repair the short. Test.

Section 29.3.6
Check for Failed Resistor

Perform the following steps to check for failed resistor:‪

  1. Unplug the engine sensor harness.
  2. Measure resistance between cavity N1 and W1. See Figure "Turbo Compressor Outlet Temperature Circuit" .
    1. If resistance is less than 1.0 K Ω, wire #416 is shorted to #906. Repair and test.
    2. If resistance is equal to 1.1 K – 1.9 K Ω, refer to "29.3.7 Check for Corrosion" .
    3. If resistance is greater than 2.0 K Ω, wire #416 or #906 is open or the resistor has failed. Replace the engine harness and test.

Section 29.3.7
Check for Corrosion

Perform the following steps to check for corrosion at the 4–pin, 10–pin interface and 30–pin connectors.‪

  1. If corroded, clean corrosion from the terminals or replace the terminals. Test.
  2. If terminals are clean, without corrosion, replace the TCO sensor. Test.


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

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