Exhaust Gas Recirculation Control Air Mass Too Large
2355-EXHAUST GAS RECIRCULATION CONTROL AIR MASS TOO LARGE
For a complete wiring diagram Refer to the Wiring Information Electrical Diagrams
- When Monitored:
With the ignition on.
- Set Conditions:
With the ignition on and Mass Airflow per cylinder does not correlate with EGR duty cycle.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.Pre-Diagnostic Troubleshooting Procedure
1. EGR VALVE
NOTE: The engine temperature must be above 160°F for this test to be valid.
NOTE: Engine must be idling in park between 600 to 650 rpm.
1. Ignition on, engine not running.
2. With the scan tool, actuate the EGR Solenoid at 0%.
3. Select Data Display and read and note the MAF Per Cyl mg/hu reading.
NOTE: The EGR actuation will only occur for 30 seconds then actuation will stop automatically. Any readings or measurements must be taken within 30 seconds of beginning of actuation.
4. Repeat the above steps actuating the EGR Valve at 0%, 40%, 60%, and 100% noting the MAF readings during each actuation. Refer to the chart and compare each of the EGR actuations and the expected MAF readings for each actuation.
Are the MAF Per Cyl mg/hu within the chart specifications for each percentage of EGR actuation?
Yes
- Go To 7
No
- Go To 2
2. EGR AIRFLOW CONTROL VALVE
1. Disconnect the hose/tube on the inlet side of the EGR Airflow Control Valve.
2. Use a mirror to observe the throttle plate position inside the EGR Airflow Control Valve for the following step.
3. With the scan tool, actuate the EGR Airflow Control Valve at 0%, 40% and 100% while observing the throttle plate position.
NOTE: The EGR actuation will only occur for 30 seconds then actuation will stop automatically. Any readings or measurements must be taken within 30 seconds of beginning of actuation.
NOTE: The throttle plate position should be wide open at 0% actuation, midway between open and closed at 40% actuation and completely closed at 100% actuation.
Does the throttle plate move smoothly, without binding, to the correct position based on actuation percentage described in the note above?
Yes
- Go To 3
No
- Check the wiring and connectors between the EGR Airflow Control Valve and the ECM for proper connection and resistance. Repair as necessary. If wiring and connections are OK, replace the EGR Airflow Control Valve.
- Perform the ECM Verification Test. Verification Tests
3. CHECK FOR INTAKE AND EXHAUST SYSTEM RESTRICTIONS
1. Turn the ignition off.
2. Inspect the exhaust system for damaged components that could cause exhaust flow blockage.
3. Inspect all air intake, crankcase vent and turbocharger related hoses/tubes and connections for damage, air leaks or blockage.
4. Inspect the air filter for excessive dirt, soiling or other problems that may cause restricted air flow.
Were any problems found?
Yes
- Repair or replace as necessary.
- Perform the ECM Verification Test. Verification Tests
No
- Go To 4
4. (A15) FUSED ASD RELAY OUTPUT CIRCUIT OPEN
1. Turn the ignition off.
2. Disconnect the EGR Solenoid harness connector.
3. Turn the ignition on.
4. Using a 12-volt test light connected to ground, check the (A15) Fused ASD Relay Output circuit at the EGR Solenoid harness connector.
NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
Is the test light illuminated and bright?
Yes
- Go To 5
No
- Repair the (A15) Fused ASD Relay Output circuit for an open.
- Perform the ECM Verification Test. Verification Tests
5. (Z42) EGR SOLENOID GROUND CIRCUIT OPEN
1. Turn the ignition off.
2. Using a 12-volt test light connected to 12-volts, check the (Z42) EGR Solenoid Ground circuit at the EGR Solenoid harness connector.
NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
Is the test light illuminated and bright?
Yes
- Go To 6
No
- Repair the (Z42) EGR Solenoid Ground circuit for an open.
- Perform the ECM Verification Test. Verification Tests
6. CHARGE AIR SYSTEM LEAK
1. Check the Charge Air System for leaks.
Does the Charge Air System leak?
Yes
- Repair the Charge Air System for leaks.
- Perform the ECM Verification Test. Verification Tests
No
- Replace the EGR Solenoid/Valve.
- Perform the ECM Verification Test. Verification Tests
7. INTERMITTENT CONDITION
1. The conditions necessary to set this DTC are not present at this time.
2. Review the scan tool environmental data. If possible, try to duplicate the conditions under which the DTC set.
3. Search for any Technical Service Bulletins (TSBs) that may apply.
4. Visually inspect the related wire harness. Disconnect all the related harness connectors. Look for any chafed, pierced, pinched, partially broken wires and broken, bent, pushed out, or corroded terminals.
5. Perform a voltage drop test on the related circuits between the suspected component and the ECM.
6. Inspect and clean all ECM, engine, and chassis grounds that are related to the most current DTC.
7. If numerous trouble codes were set, use a schematic and inspect any common ground or supply circuits.
8. For intermittent DTCs check for restrictions in the Intake and Exhaust system, proper installation of Sensors, vacuum leaks and leaks in the Charge Air Cooler system.
9. Sensors, vacuum leaks and leaks in the Charge Air Cooler system.
10. A co-pilot, data recorder, and/or lab scope should be used to help diagnose intermittent conditions.
Were any problems found during the above inspections?
Yes
- Perform the necessary repairs.
- Perform the ECM Verification Test. Verification Tests
No
- Test Complete.