A typical diagnosis is an Engine Oil Pressure Sensor circuit failed high.
26.2.1
Failed High Circuit Check
Check as follows:
1. Turn the ignition ON (key On, engine OFF).
2. Check for multiple codes:
[a] If 100/3, 94/3 and 4407/3 are present repair the short to power between pin 82 of
the 120–pin MCM connector and the Engine Oil, Doser Fuel Line and Doser Fuel
Compensation Sensors. Refer to section 26.2.1.1.
[b] If only 100/3 is present, go to step 3.
3. Disconnect the Engine Oil Pressure Sensor.
4. Measure the voltage between pin 3 of the EOP Sensor harness connector and ground.
See Figure 26-1.
[a] If voltage is greater than 5 volts, repair the short to power between pin 82 of the
120–pin MCM connector and pin 2 of the EOP Sensor connector. (see Figure 26-2).
Refer to section 26.2.1.1.
[b] If no voltage is present, go to step 5 (see Figure 26-2).
5. Measure the voltage between pin 2 of the EOP Sensor harness connector and ground.
[a] If voltage is greater than 5 volts, repair the short to power between pin 105 of the
120–pin MCM connector and pin 3 of the EOP Sensor connector. (see Figure 26-2).
Refer to section 26.2.1.1.
[b] If no voltage is present, go to step 6.
6. Measure the voltage between pins 1 and 3 of the EOP Sensor.
[a] If voltage is less than 5 volts, repair the open between pin 105 of the 120–pin MCM
connector and pin 1 of the EOP Sensor connector. Refer to section 26.2.1.1.
[b]If the voltage is between 4.5 and 5 volts, repair the open between pin 54 of the
120–pin MCM connector and pin 2 of the EOP Sensor connector. Refer to section 26.2.1.1.
26.2.1.1
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.
