Detroit Diesel MBE 4000 DDEC VI Troubleshooting Manual page 743

113.1 SPN 3663/FMI 5
This diagnosis is typically the Electronic Unit Pump current is below normal or an open circuit
fault.
113.1.1 Open Circuit Check
Check as follows:
1. Check for multiple codes.
[a] If fault code 168/1 is active in addition to 3663/5, service 168/1 first. Refer to section
31.2.
[b] If fault 3662/5 and 3664/5 are active in addition to 3663/5, contact the Detroit Diesel
Customer Support Center (313–592–5800) for MCM replacement.
[c] If only fault code 3663/5 is active, go to step 2.
2. The ignition should still be ON (key ON, engine OFF).
3. Measure the voltage between pins 1 and 2 of Electronic Unit Pump #5. See Figure 113-1.
Figure 113-1 Electronic Unit Pump #5
[a] If the voltage is greater than 11.5 volts, replace Electronic Unit Pump #5.
[b] If the voltage is less than 11.5 volts, go to step 4.
4. Measure the voltage between pin 1 of the Electronic Unit Pump #5 and ground.
[a] If the voltage is greater than 11.5 volts, repair the open between pin 8 of the 120–pin
MCM connector and pin 2 of Electronic Unit Pump #5. Refer to section 113.1.1.1.
[b] If the voltage is less than 11.5 volts, repair the open between pin 9 of the 120–pin
MCM connector and pin 1 of Electronic Unit Pump #5. Refer to section 113.1.1.1.
All information subject to change without notice.
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MBE 4000 DDEC VI TROUBLESHOOTING GUIDE
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