The diagnostic condition is typically CKP Sensor has an open circuit.
56.2.1
Open Circuit Check
Check as follows:
1. Disconnect the CKP Sensor.
2. Measure the resistance across pins 1 and 2 of the CKP Sensor. See Figure 56-2.
[a] If the resistance is greater than 140 Ω, replace CKP Sensor. Refer to section 56.2.2.1.
[b] If the resistance is less than 140 Ω, go to step 3.
3. Disconnect the 120–pin MCM connector.
4. Measure the resistance across pins 1 and 2 of the CKP Sensor harness connector.
[a] If the resistance is greater than 5 Ω, go to step 5.
[b] If the resistance is less than 5 Ω, repair the short between pins 1 and 2 of the CKP
Sensor harness connector and pins 42 and 43 of the 120–pin MCM connector.
See Figure 56-2. Refer to section 56.2.2.1.
5. Measure the resistance between pin 1 of the CKP Sensor harness connector and pin 42
of the 120–pin MCM connector.
[a] If the resistance is greater than 5 Ω, repair the open between pin 1 of the CKP Sensor
harness connector and pin 42 of the 120–pin MCM connector. Refer to section 56.2.2.1.
[b] If the resistance is less than 5 Ω, go to step 6.
6. Measure the resistance between pin 2 of the CKP Sensor harness connector and pin 43 of the 120–pin MCM connector.
[a] If the resistance is greater than 5 Ω, repair the open between pin 2 of the CKP Sensor
harness connector and pin 43 of the 120–pin MCM connector. Refer to section 56.2.2.1.
[b]If the resistance is less than 5 Ω, refer to section 56.2.2.
56.2.2
Crankshaft Position Sensor Gap Check
Check as follows:
1. Bar the engine until the CKP Sensor is over a CKP tooth of the pulse wheel.
2. Check the gap between the CKP Sensor and the tooth of the pulse wheel (0.020 to 0.040
in.). A depth micrometer can be used.
[a] If the gap setting is correct, repeat steps 1 and 2. If the results are the same, call the
Detroit Diesel Customer Support Center (313–592–5800).
[b] If the gap setting is not correct, adjust the CKP Sensor until the gap setting is correct
and refer to section 56.2.2.1. If the problem returns, the pulse wheel may be loose or bad or damaged.
56.2.2.1
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.
