MBE 4000 DDEC VI Troubleshooting – Section 19.2 SPN 27/FMI 4

Section 19.2
SPN 27/FMI 4

This diagnostic condition is typically a circuit failed high.‪

Section 19.2.1
EGR Valve Position Circuit Check

Check as follows:‪

1. Check for multiple codes.
   1. If 27/4, 2791/4 and 2791/5 are present, repair the open between pin 62 of the 120–pin MCM connector and pin 2 of the EGR valve. Refer to "19.2.1.1 Verify Repairs" .
   2. If 27/4 and 3471/4 are present, go to step 6 .
   3. If 27/4 and 3482/4 are present, go to step 8 .
   4. If 27/4 and 1072/4 are present, go to step 10 .
   5. If 27/4 and 615/4 are present, go to step 13 .
   6. If only 27/4 is present, go to step 2 .
2. Disconnect the EGR valve harness connector.
3. Measure the resistance between pin 4 of the EGR valve harness connector and ground.
   1. If the resistance is less than 1 kΩ, repair the short to ground between pin 4 of the EGR valve harness connector and pin 60 of the 120–pin MCM connector. Refer to "19.2.1.1 Verify Repairs" .
   2. If the resistance is greater than 1 kΩ, go to step 4 .
4. Disconnect the MCM 120–pin connector.
5. Measure the resistance between pin 4 of the EGR valve harness connector and pin 60 of the 120–pin MCM connector.
   1. If the resistance is greater than 3 Ω, repair the open between pin 4 of the EGR valve harness connector and pin 60 of the 120–pin MCM connector. Refer to "19.2.1.1 Verify Repairs" .
   2. If the resistance is less than 3 Ω, replace the EGR valve. Refer to "19.2.1.1 Verify Repairs" .
6. Monitor the active codes; unplug the Electronic Dosing Valve (EDV). Does the code become inactive?
   1. If yes, replace the EDV. Refer to "19.2.1.1 Verify Repairs" .
   2. If no, go to step 7 .
7. Unplug the EGR valve. Does the code become inactive?
   1. If yes, replace the EGR valve. Refer to "19.2.1.1 Verify Repairs" .
   2. If no, repair the short to ground on circuit 65 of the 120–pin MCM connector. Refer to "19.2.1.1 Verify Repairs" .
8. Monitor the active codes; unplug the Fuel Cutoff Valve (FCV). Does the code become inactive?
   1. If yes, replace the FCV. Refer to "19.2.1.1 Verify Repairs" .
   2. If no, go to step 9 .
9. Unplug the EGR valve. Does the code become inactive?
   1. If yes, replace the EGR valve. Refer to "19.2.1.1 Verify Repairs" .
   2. If no, repair the short to ground on circuit 69 of the 120–pin MCM connector. Refer to "19.2.1.1 Verify Repairs" .
10. Monitor the active codes; unplug the EGR valve. Does the code become inactive?
    1. If yes, replace the EGR valve. Refer to "19.2.1.1 Verify Repairs" .
    2. If no, go to step 11 .
11. Turn the ignition to the OFF position.
12. Disconnect the constant throttle valve. Does the code become inactive?
    1. If yes, replace the constant throttle valve. Refer to "19.2.1.1 Verify Repairs" .
    2. If no, repair the short to ground on circuit 32 of the 120–pin MCM connector. Refer to "19.2.1.1 Verify Repairs" .
13. Monitor the active codes; unplug the Fuel Cutoff Valve (FCV). Does the code become inactive?
    1. If yes, replace the FCV. Refer to "19.2.1.1 Verify Repairs" .
    2. If no, go to step 14 .
14. Unplug the EGR valve. Does the code become inactive?
    1. If yes, replace the EGR valve. Refer to "19.2.1.1 Verify Repairs" .
    2. If no, go to step 15 .
15. Unplug the Electronic Dosing Valve (EDV). Does the code become inactive?
    1. If yes, replace the EDV. Refer to "19.2.1.1 Verify Repairs" .
    2. If no, repair the short to ground on circuits 62 and/or 64 of the 120–pin MCM connector. Refer to "19.2.1.1 Verify Repairs" ..

Section 19.2.1.1
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.