DD15 Troubleshooting – Section 73.3 SPN 723/FMI 8

Section 73.3
SPN 723/FMI 8

A typical diagnosis is time out.‪

Check as follows:‪

1. Disconnect the MCM 120–pin connector.
2. Measure the resistance between pins 44 and 45 of the MCM 120–pin connector.
   1. If the resistance is greater than 140 Ω, go to step 5 .
   2. If the resistance is less than 140 Ω, go to the next step.
3. Disconnect the CMP Sensor.
4. Measure the resistance between pins 44 and 45 of the MCM 120–pin connector.
   1. If the resistance is less than 3 Ω, repair the short between pins 44 and 45 of the MCM 120–pin connector and the CMP Sensor. Refer to "73.3.1 Verify Repairs" .
   2. If the resistance is greater than 3 Ω, replace the CKP Sensor. Refer to "73.3.1 Verify Repairs" .
5. Disconnect the CMP Sensor.
6. Jumper pins 1 and 2 of the CKP Sensor harness.
7. Measure the resistance between pins 44 and 45 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 "73.3.1 Verify Repairs" .
   2. If the resistance is less than 3 Ω, replace the CKP Sensor. Refer to "73.3.1 Verify Repairs" .

Section 73.3.1
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.

   ENGINE EXHAUST ‪
   To avoid injury from inhaling engine exhaust, always operate the engine in a well-ventilated area. Engine exhaust is toxic.‪

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.