This diagnostic condition is typically camshaft and crankshaft signals not matching.
56.4.1
Camshaft and Crankshaft Signals Not Matching
Check as follows:
1. Remove CKP and CMP sensors.
2. Reseat the CKP Sensor until it touches the flywheel and reseat the CMP Sensor until it
touches the cam gear. Check codes.
[a] If 636/7 is not active, refer to section 56.4.1.1.
[b] If 636/7 is active, go to step 3.
3. Remove CKP and CMP sensors.
4. Remove O-ring in CMP Sensor opening.
5. Reseat CKP Sensor until it touches the flywheel and reseat the CMP Sensor without the
O-ring until the sensor touches the cam gear.
[a] If 636/7 is not active, replace the O-ring with a smaller O-ring. Refer to section
56.4.1.1.
[b] If 636/7 is active, go to step 6.
6. Disconnect the CKP Sensor connector and measure the sensor reisitance.
[a] If the sensor resistance is not between 1000 Ω and 1385 Ω, replace the sensor.
refer to section 56.4.1.1.
[b] If the sensor resistance is between 1000 Ω and 1385 Ω, go to step 7.
7. Verify that all flywheel holes or slots are present by viewing through the access hole
on the flywheel housing.
[a] If the flywheel holes or slots are missing or damaged, replace the flywheel as needed.
refer to section 56.4.1.1.
[b] If the flywheel holes or slots are all present, go to step 8.
8. Replace the MCM. Refer to section 56.4.1.1.
56.4.1.1
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.
