Diagnosing a 2018 Chrysler 300 with a Hard Start and a P0339 fault code

In this video, Bernie diagnoses a 2018 Chrysler 300 with a hard starting condition and a stored fault code for the crankshaft position sensor (CKP sensor). The stored code was a P0339 Crankshaft Position Sensor “A” malfunction intermittent. Bernie confirmed the hard start, at first it stalled, then started hard as described. Engine runs smooth once running, no misfire.

Two new crankshaft position sensor have already been installed, so there’s a pretty good chance, that won’t be the issue.

The next step is to connect the ATS 8-channel eSCOPE to monitor the camshaft and crankshaft positions sensors, as well as the ignition coil and injector for cylinder #1. Using the deep record feature, no trigger has to be set, all of the voltage data is recorded and easily reviewed.

When starting the ignition coil is not consistently being fired, Bernie zooms in to take a look and finds the crankshaft sensor signal looks off. One of the trigger wheel pulses is wrong. With the crank sensor removed, Bernie inspects the trigger wheel using the ATS iC inspection camera (Borescope), he finds a bent tooth on the trigger wheel.

The vehicle will need a new trigger wheel to remedy the hard starting problem.

Diagnostic equipment used:
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