Section 56.5
SPN 636/FMI 8

The diagnostic condition is typically CKP Sensor Time Out.‪

Section 56.5.1
Sensor Time Out Check

Check as follows:‪

1. Disconnect the MCM 120–pin connector.
2. Measure the resistance between pins 42 and 43 of the MCM 120–pin connector.
   1. If the resistance is less than 140 Ω, go to step 3 .
   2. If the resistance is greater than 140 Ω, go to step 5 .
3. Disconnect the CKP Sensor.
4. Measure the resistance between pins 42 and 43 of the MCM 120–pin connector.
   1. If the resistance is less than 3 Ω, repair the short between pins 42 and 43 of the MCM 120–pin connector and the CKP Sensor. Refer to "56.5.1.1 Verify Repairs" .
   2. If the resistance is greater than 3 Ω, replace the CKP Sensor. Refer to "56.5.1.1 Verify Repairs" .
5. Disconnect the CKP Sensor. See Figure "Crankshaft Position Sensor" .
   

   Figure 1. Crankshaft Position Sensor

6. Jumper pins 1 and 2 of the CKP Sensor harness.
7. Measure the resistance between pins 42 and 43 of the MCM 120–pin connector.
   1. If the resistance is greater than 3 Ω, repair the open between pins 42 and 43 of the MCM 120–pin connector and the CKP Sensor connector. Refer to "56.5.1.1 Verify Repairs" .
   2. If the resistance is less than 3 Ω, replace the CKP Sensor. Refer to "56.5.1.1 Verify Repairs" .

Section 56.5.1.1
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.