The diagnostic condition is typically an open circuit.
77.1.1
Open Circuit Check
Perform the following steps to troubleshoot an open circuit.
1. Disconnect CMP Sensor
2. Measure the resistance across pins 1 and 2 of the CMP Sensor.See Figure 77-1.
[a] If the resistance is less than 140 Ω, go to step 3.
[b] If the resistance is greater than 140 Ω, replace the CMP Sensor. Refer to section
77.1.1.1.
3. Disconnect the 120–pin MCM connector.
4. Measure the resistance across pins 1 and 2 of the CMP harness connector.
[a] If the resistance is less than 5 Ω, repair short between pins 1 and 2 of the CMP harness connector and the pins 44 and 45 of the MCM 120 pin connector. Refer to section 77.1.1.1.
[b] If the resistance is greater than 5 Ω, go to step 5.
5. Measure the resistance between pin 1 of the CMP harness connector and pin 44 of the MCM 120 pin connector
[a] If the resistance is greater then 5 ohms, repair open between pin 1 of the CMP harness
connector and pin 44 of the MCM 120 pin connector. Refer to section 77.1.1.1.
[b] If the resistance is less than 5 Ω, go to step 6.
6. Measure the resistance between pin 2 of the CMP harness connector and pin 45 of the
MCM 120 pin connector.
[a] If the resistance is greater then 5 ohms, repair open between pin 2 of the CMP harness
connector and pin 45 of the MCM 120 pin connector. Refer to section 77.1.1.1.
[b] If the resistance is less than 5 Ω, review steps 2 through 6. If the results are the same,
contact the Detroit Diesel Customer Support Center (313–592–5800).