Medium and Heavy Trucks
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SID 21 FMI 2 FLASH CODE 143 wrong number of CAMP signal transistions per cam revolution
Incorrect Crankshaft Position (CKP) signalsignature - Check CKP sensor and circuit147 SID 64 2
Camshaft Position Output (CMPO) transitionoccurred at the wrong Crankshaft PositionOutput (CKPO) tooth - Check timing andCamshaft Position Sensor (CMP)552 SID 22 2
These faults are an indication of a faulty cam/crank position sensor or wiring harness for the sensors. Check for both.
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Do you have diamond logic or a scan tool that will read live data and Engine RPM while cranking?
Its possible the sensor air gap is incorrect, other mechanical issues causing the sensor not to read the gear, or possible ECM software issues.
Another rare but possible cause is interference from a short such as an alternator issue or poor grounds etc that would throw off the sensor signals to the ECM.
Click on this link for the schematic.
Min 100 Hz @ crank. The specs are in page 2 of the link I provided.
Magnetic pickup sensors• CKP• CMP• VSSA magnetic pickup sensor generates an alternatingfrequency that indicates rotational speed. Magneticpickup sensors have a two wire connection for signaland ground. The sensor has a permanent magnetcore surrounded by a wire coil. The signal frequencyis generated by the rotation of gear teeth that disturbthe magnetic field.Crankshaft Position (CKP) sensorThe CKP sensor indicates crankshaft speed andposition.The CKP sensor provides the ECM with a signalthat indicates crankshaft speed and position. As thecrankshaft turns the CKP sensor detects a 60 toothtiming disk on the crankshaft. Teeth 59 and 60 aremissing. By comparing the CKP signal with the CMPsignal, the ECM calculates engine rpm and timingrequirements.The CKP is installed in the front right side of the lowercrankcase.
Camshaft Position (CMP)The CMP sensor indicates camshaft speed andposition.The CMP sensor sends a pulsed signal to the ECMwhen a single peg on the camshaft rotates pastthe CMP sensor once during each revolution of thecamshaft. The ECM calculates camshaft speed andposition from CMP signal frequency.The CMP sensor is installed in the front left side of thecrankcase.
I posted an offer for the manual in file sharing if interested let me know once accepted so I know to post the link.
The IDM has three functions: • Electronic distributor for injectors • Power source for injectors • IDM and injector diagnostics Electronic distributor for injectors The IDM distributes current to the injectors. The IDM controls fueling to the engine by sending high voltage pulses to the OPEN and CLOSE coils of the injector. The IDM uses information from the ECM to determine the timing and quantity of fuel for each injector. The ECM uses CMP and CKP input signals to calculate engine speed and position. The ECM conditions both input signals and supplies the IDM with CMP and CKP output signals. The IDM uses CMP and CKP output signals to determine the correct sequence for injector firing. The ECM sends information (fuel volume, EOT, and ICP) through the CAN 2 link to the IDM; the IDM uses this information to calculate the injection cycle.