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MBE 900 & MBE 4000 EGR – Section 4.3 Troubleshooting of Performance Codes

Section 4.3
Troubleshooting of Performance Codes

Performance codes indicate the detection of mechanical failures by the DDEC system. The response would be to troubleshoot a PID or SID as follows.‪

warning

PERSONAL INJURY ‪

To avoid injury, use care when working around moving belts and rotating parts on the engine.‪
warning

PERSONAL INJURY ‪

Diesel engine exhaust and some of its constituents are known to the State of California to cause cancer, birth defects, and other reproductive harm.‪

  • Always start and operate an engine in a well ventilated area.
  • If operating an engine in an enclosed area, vent the exhaust to the outside.
  • Do not modify or tamper with the exhaust system or emission control system.

Note: The EGR systems in the MBE 4000 and MBE 900 engines contain fewer components and use simpler control logic than the other series of Detroit Diesel engines. Therefore, using the DTCs should be the primary means of solving troubleshooting problems. The Detroit Diesel Diagnostic Link (DDDL) snapshots are not as dynamic on the MBE engines and are usually just used to supplement the DTCs when troubleshooting.

Section 4.3.1
DESCRIPTION OF SID 146

SID 146 indicates that during engine operation, the DDEC-ECU received EGR system parameters outside their normal range resulting in one or more of the following fault codes:‪

Section 4.3.2
TROUBLESHOOTING SID 146

Data for the EGR temperature sensor is routed through pins 28 and 22 of the 55-pin connector. Control of the EGR valve is routed through pins 11, 42, and 50 of the 55-pin connector. See Figure "Pin Locations on 55-Pin Connector" .‪

Click to see this graphic in a separate window

 1. 55-Pin Connector‪

 ‪

Figure 1. Pin Locations on 55-Pin Connector

The following procedures will troubleshoot SID 146.‪

Section 4.3.2.1
146/0 — EGR Temperature above Normal

Perform the following steps to troubleshoot EGR temperature above normal:‪

  1. Disconnect the EGR temperature sensor connector and check for active fault codes. See Figure "EGR Temperature Sensor Pins and 55-Pin Connector Wires" .
    Click to see this graphic in a separate window

    Figure 2. EGR Temperature Sensor Pins and 55-Pin Connector Wires

    1. If fault code s 146/0 is the only active code, repair the short between wires for pins 28 to 1 and pins 22 to 3. Erase the fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    2. If fault code s 146/1 is active code, replace the EGR temperature sensor. Erase the fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    3. If fault code s 146/0 is still active code, go to step 2 .
  2. Bridge pin 1 of the EGR temperature sensor connector to ground and check for active fault codes. See Figure "EGR Temperature Sensor Pins and 55-Pin Connector Wires" .
    1. If fault code s 146/0 is active, repair open circuit in wire between pin 28 of the 55-pin connector and pin 1 of sensor connector.
    2. If fault code s 146/0 is no longer active, erase fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    3. If fault code s 146/0 is still active, go to step 3 .
  3. Measure the resistance between pin 22 of the 55-pin connector and pin 3 of the EGR temperature sensor connector. See Figure "EGR Temperature Sensor Pins and 55-Pin Connector Wires" .
    1. If resistance is greater than 3 Ω, repair open circuit in wire between pin 22 of the 55-pin connector and pin 3 of sensor connector.
    2. If resistance is less than 3 Ω, check all contacts and connections. If any corrosion is evident, remove it.
    3. If fault code s 146/0 is no longer active, erase fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    4. If fault code s 146/0 is still active, go to step 4 .
  4. Check coolant usage.
    1. If coolant usage indicates a leak, perform an EGR Cooler Inspection. Refer to appendix "7.2.2 Service Information Letters" , Service Information Letter 04 TS - 38. Clean and replace parts as indicated by inspection. Erase fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    2. If coolant usage is normal, go to step 5 .
  5. Check the following vehicle components for proper function. Repair or replace as required. Refer to the appropriate OEM Vehicle service manual as required.
    1. Check airflow through the CAC and radiator.
    2. Check fan belt condition for possible slippage.
    3. Check the fan shroud for proper position.
    4. Check the radiator hoses for collapsing.
    5. Check the viscous fan for proper operation.
    6. If fault code s 146/0 is no longer active, erase fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    7. If fault code s 146/0 is still active, go to step 6 .
  6. Check for damage to the reed valves as follows:
    1. Look for open valves (damaged or stuck). Replace valves as required.
    2. Look for heavy soot deposits on the valves. If necessary, clean valves. Erase fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    3. If fault code s 146/0 is still active, contact the Detroit Diesel Customer Support Center at 313-592-5800.
Section 4.3.2.2
146/1 — EGR Temperature below Normal

Perform the following steps to troubleshoot EGR temperature below normal:‪

  1. Measure the resistance between pins 1 and 3 on the EGR temperature sensor. See Figure "EGR Temperature Sensor Pins and 55-Pin Connector Wires" .
    Click to see this graphic in a separate window

    Figure 3. EGR Temperature Sensor Pins and 55-Pin Connector Wires

    1. If resistance is less than 3 Ω, replace the EGR temperature sensor. Erase the fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    2. If resistance is greater than 3 Ω, go to step 2 .
  2. Measure the resistance between pin 28 of the 55-pin connector and pin 1 of the EGR temperature sensor connector. See Figure "EGR Temperature Sensor Pins and 55-Pin Connector Wires" .
    1. If resistance is less than 3 Ω, repair the short in the wire. Erase the fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    2. If resistance is greater than 3 Ω, go to step 3 .
  3. Measure the resistance between pin 22 of the 55-pin connector and pin 3 of the EGR temperature sensor connector. See Figure "EGR Temperature Sensor Pins and 55-Pin Connector Wires" .
    1. If resistance is less than 3 Ω, repair the short in the wire. Erase the fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    2. If resistance is greater than 3 Ω, go to step 4 .
  4. Inspect the EGR control valve for mechanical problems.
    1. Ensure the valve moves freely between the open and closed positions. Ensure the springs return the valve to the closed position. If required, replace the valve. Erase the fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    2. If the valve functions properly, go to step 5 for the MBE 4000 engine and step 6 for the MBE 900 engine.
  5. For the MBE 4000 engine, inspect the EGR shutoff valve.
    1. Ensure the valve moves freely between the open and closed positions. Ensure the valve stays in the open position when no air pressure is applied. If required, replace the valve. Erase the fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    2. If the valve functions properly, go to step 6 .
  6. Check for damage to the reed valves as follows:
    1. Look for open valves (damaged or stuck). Replace valves as required.
    2. Look for heavy soot deposits on the valves. If necessary, clean valves. Erase fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    3. If the reed valve is undamaged, go to step 7 .
  7. Visually inspect the EGR cooler for damage or leaking.
    1. If the cooler is damaged and leaking, repair or replace cooler as required. Erase the fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    2. If fault code s 146/1 is still active, contact the Detroit Diesel Customer Support Center at 313-592-5800.
Section 4.3.2.3
146/2 — Erratic Data

Perform the following steps to resolve erratic EGR data:‪

  1. Check active codes.
    1. If fault codes s 146/2 and s 146/0 are active at the same time, refer to "4.3.2.1 146/0 — EGR Temperature above Normal" .
    2. If fault code s 146/2 is the only active code, go to step 2 .
  2. Check the resistance between pin 42 of the 55-pin connector and pin 2 of the EGR valve connector. See Figure "EGR Valve Wiring Diagram" .
    Click to see this graphic in a separate window

    Figure 4. EGR Valve Wiring Diagram

    1. If the resistance is greater than 3 Ω, repair open circuit in wire between pin 42 of the 55-pin connector and pin 2 of the EGR valve connector. Erase fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    2. If the resistance is less than 3 Ω, go to step 3 .
  3. Bridge pin 3 of the EGR valve connector to ground and check for active fault codes. See Figure "EGR Valve Wiring Diagram" .
    1. If fault code s 146/2 is no longer active, repair open circuit in wire between pin 11 of the 55-pin connector and pin 3 of the EGR valve connector. If fault code s 146/2 is no longer active, erase fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    2. If fault code s 146/2 is still active, go to step 4 .
  4. Check the resistance between pin 50 of the 55-pin connector and pin 1 of the EGR valve connector. See Figure "EGR Valve Wiring Diagram" .
    1. If the resistance is greater than 3 Ω, repair the open circuit in the wire between pin 50 of the 55-pin connector and pin 1 of the EGR valve connector. If fault code s 146/2 is no longer active, erase fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    2. If fault code s 146/2 is still active, go to step 5 .
  5. Check all contacts and connections. Remove corrosion as required. Check for active fault codes.
    1. If fault code s 146/2 is no longer active, erase fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    2. If fault code s 146/2 is still active, go to step 6 .
  6. Check coolant usage.
    1. If coolant usage indicates a leak, perform an EGR Cooler Inspection. Refer to appendix "7.2.2 Service Information Letters" , Service Information Letter 04 TS - 38. Clean and replace parts as indicated by inspection. Erase fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    2. If coolant usage is normal and fault code s 146/2 is still active, contact the Detroit Diesel Customer Support Center at 313-592-5800.
Section 4.3.2.4
146/7 — EGR Valve not Responding

Perform the following steps to resolve an EGR valve not responding:‪

  1. Check active fault codes.
    1. If fault codes s 146/7 and s 146/2 are active at the same time, refer to "4.3.2.3 146/2 — Erratic Data" .
    2. If only fault code s 146/7 is active, go to step 2 .
  2. Check the engine harness wiring from the 55-pin connector to the EGR valve connector. See Figure "EGR Valve Wiring Diagram" .
    Click to see this graphic in a separate window

    Figure 5. EGR Valve Wiring Diagram

    1. If the resistance less than 3 Ω for wires from pins 50 to 1, pins 42 to 2, or pins 11 to 3, then there is a short in the wire. Repair the short and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    2. If the resistance is greater than 10 kΩ for wires from pins 50 to 1, pins 42 to 2, or pins 11 to 3, then there is a open circuit in the wire. Repair the open circuit and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    3. Check all contacts and connections. Remove corrosion as required. If fault code s 146/7 is still active, go to step 3 .
  3. Check the EGR temperature sensor. See Figure "EGR Temperature Sensor Pins and 55-Pin Connector Wires" .
    Click to see this graphic in a separate window

    Figure 6. EGR Temperature Sensor Pins and 55-Pin Connector Wires

    1. Measure the resistance between pins 1 and 3 on the EGR temperature sensor. If resistance is less than 3 Ω, replace the EGR temperature sensor. Erase the fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    2. Bridge pins 1 and 3 on the EGR temperature sensor connector and check for active fault codes. If fault code s 146/0 is active, replace the EGR temperature sensor, erase fault code memory, and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    3. If fault code s 146/7 is still active, go to step 4 .
  4. Check coolant usage.
    1. If coolant usage indicates a leak, perform an EGR Cooler Inspection. Refer to appendix "7.2.2 Service Information Letters" , Service Information Letter 04 TS - 38. Clean and replace parts as indicated by inspection. Erase fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    2. If coolant usage is normal and fault code s 146/2 is still active, contact the Detroit Diesel Customer Support Center at 313-592-5800.
Section 4.3.2.5
146/12 — Bad Component

Perform the following steps to resolve a Bad Component fault code:‪

  1. If fault code s 146/12 is active, check the engine harness wiring from the 55-pin connector to the EGR valve connector. See Figure "EGR Valve Wiring Diagram" .
    Click to see this graphic in a separate window

    Figure 7. EGR Valve Wiring Diagram

    1. If the resistance is less than 3 Ω for wires from pins 50 to 1, pins 42 to 2, or pins 11 to 3, then there is a short in the wire. Repair the short and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    2. If the resistance is greater than 10 kΩ for wires from pins 50 to 1, pins 42 to 2, or pins 11 to 3, then there is a open circuit in the wire. Repair the open circuit and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    3. If fault code s 146/12 is still active, replace EGR valve. Erase fault code memory and verify repairs. Refer to "4.3.2.6 Verifying Repairs" .
    4. If fault code s 146/12 is still active, go to step 2 .
  2. Contact the Detroit Diesel Customer Support Center at 313-592-5800.
Section 4.3.2.6
Verifying Repairs

Perform the following steps to verify repairs.‪

  1. Turn ignition OFF.
  2. Reconnect all connectors.
  3. Turn ignition ON.
  4. Start and run the engine for one minute.
  5. Stop engine.
  6. Check active codes.
    1. If no codes are displayed, troubleshooting is complete.
    2. If a fault code other than SID 146 is logged, refer to Detroit Diesel MBE Electronic Controls Troubleshooting Guide , 6SE422.
    3. If a fault code in SID 146 is logged, refer to:

MBE 900 and MBE 4000 EGR Technician's Manual - 7SE940
Generated on 10-13-2008

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