SPN 636/FMI 4
This diagnostic condition is typically the CKP Sensor shorted to ground.
Note: If the sensor is removed, be sure to check the sensor tip for metal debris and clutch material and clean it if necessary.
Check as follows:
- Disconnect the CKP Sensor and clean the sensor tip.
- Measure the resistance between pin 1 of the CKP Sensor and ground.
- If the resistance is greater than 5 Ω, go to the next step.
- If the resistance is less than 5 Ω, replace the sensor. Refer to “56.4.1 Verify Repairs” .
- Measure the resistance between pin 2 of the CKP Sensor and ground.
- If the resistance is greater than 5 Ω, go to the next step.
- If the resistance is less than 5 Ω, replace the sensor. Refer to “56.4.1 Verify Repairs” .
- Disconnect the 120–pin MCM connector.
- Measure the resistance across pins 1 and 2 of the CKP Sensor harness connector.
- If the resistance is greater than 5 Ω, go to the next step.
- If the resistance is less than 5 Ω, repair the short between the CKP Sensor harness connector pins 1 and 2 and pins 42 and 43 of the 120–pin MCM connector. Refer to “56.4.1 Verify Repairs” .
- Measure the resistance between pin 1 of the CKP Sensor harness connector and ground.
- If the resistance is greater than 5 Ω, go to the next step.
- If the resistance is less than 5 Ω, repair the short to ground between pin 1 of the CKP Sensor harness connector and pin 42 of the 120–pin MCM connector. Refer to “56.4.1 Verify Repairs” .
- Measure the resistance between pin 2 of the CKP Sensor harness connector and pin 43 of the 120–pin MCM connector.
- If the resistance is greater than 5 Ω, reconnect the 120–pin MCM connector and review the previous steps. If the results are the same, call the Detroit Diesel Customer Support Center (313–592–5800).
- If the resistance is less than 5 Ω, repair the short to ground between pin 2 of the CKP Sensor harness connector and pin 43 of the 120–pin MCM connector. Refer to “56.4.1 Verify Repairs” .
Verify Repairs
Verify repairs as follows:
- Turn ignition OFF.
- Reconnect any electrical connections that were disconnected to perform the diagnosis.
- 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. - Start and bring engine up to operating temperature (over 140°F/60°C).
- Verify operation is satisfactory and no warning lamps illuminate. If warning lamps illuminate, troubleshoot the codes.