This diagnostic condition is typically an open circuit fault.
93.3.1 Open Circuit Check
Check as follows:
1. Check for multiple codes.
[a] If 2791/5, 27/4, and 1073/4 are present, repair the open between pin 62 of the 120–pin MCM connector and EGR valve and front Jake Brake solenoid. Refer to section 93.3.1.1.
[b] If only 2791/5 is present, go to step 2.
2. Disconnect the EGR valve.
3. Disconnect the 120–pin MCM connector.
4.Measure the resistance between pin 1 of the EGR valve harness connector and pin 61
of the 120–pin MCM connector.
[a]If the resistance is greater than 3 Ω, repair the open between pin 1 of the EGR valve harness connector and pin 61 of the 120–pin MCM connector. Refer to section 93.3.1.1.
[b] If the resistance is less than 3 Ω, replace the EGR valve. Refer to section 93.3.1.1.
93.3.1.1 Verify Repairs
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.
