The diagnostic condition is typically CKP Sensor Signal Voltage Too Low.
56.1.1
Low Signal Voltage Check
Check low signal voltage as follows:
1. If fault occurs only when cranking the engine (and engine will not start), check that the
CKP and Camshaft Position (CMP) sensors are correctly wired to the MCM. See Figure 56-1.
[a] If wires are not correctly wired, repair or replace wires as required. Refer to section
56.1.1.1.
[b] If wires are correctly wired, go to step 2.
2. If fault occurs at other times then when cranking the engine, check that the CKP Sensor
position is correct (the sensor is seated in all the way).
[a] If fault is not active after checking CKP Sensor position, repair the CKP Sensor clamping sleeve. Refer to section 56.1.1.1.
[b] If fault is still active after checking the CKP Sensor position, go to step 3.
3. Check the flywheel position through the inspection window of the timing case using
turning tool. Look for timing marks and damage.
[a] If the flywheel is out of position, repair or replace, as required. Refer to section 56.1.1.1.
[b] If the flywheel is not out of position, go to step 4.
4. Check crankshaft axial play.
[a] If axial play is not within specifications, repair or replace crankshaft thrust bearings,
as required. Refer to section 56.1.1.1.
[b] If axial play is within specifications, replace the MCM. Refer to section 56.1.1.1.
56.1.1.1
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.
