This diagnostic condition is typically the EGR valve stuck open.
Valve Function Check
Check as follows:
1. Turn the ignition ON (key ON, engine OFF).
2. Using DDDL 7.0, monitor the EGR Actual Position while activating PWM1 to 50% for 15 seconds.
3. Is the EGR Actual Position reading between 42 and 48%?
[a] If yes, go to step 6.
[b] If no, go to step 4.
4. Remove the EGR valve.
5. Inspect the EGR valve butterfly for signs of excessive soot or white residue.
[a] If white residue is found, repair the cause of coolant contamination and possible EGR cooler failure. Once the source of coolant contamination is repaired, replace the EGR valve. Refer to section 126.96.36.199.
[b] If excessive soot residue if found, correct the cause of soot contamination and possible CAC system leaks. Once the source of soot contamination is repaired, replace the EGR valve. Refer to section 188.8.131.52.
[c] If no contamination is found, replace the EGR valve. Refer to section 184.108.40.206.
6. Disconnect the EGR valve connector.
7. Inspect the connector for bent, spread or corroded pins.
[a] If damage is found, repair as necessary.
[b] If no damage is found, contact the Detroit Diesel Customer Support Center at 313–592–5800.
Verify repairs as follows:
1. Turn ignition OFF.
2. Reconnect any electrical connections that were disconnected to perform the diagnosis.
3. Clear codes with DDDL 7.0 or latest version.
4. Start and bring engine up to operating temperature (over 140°F/60°C).
5. Verify operation is satisfactory and no warning lamps illuminate. If warning lamps
illuminate, troubleshoot the codes. If assistance is required, call the Detroit Diesel
Customer Support Center at 313–592–5800.