DTC P0370: Timing Reference High Resolution: Description

The optical sensor provides a high resolution signal to the Powertrain Control Module (PCM) by counting the pulses on the sensor disk which is located in the injection pump. The high resolution is one of the most important inputs by the PCM for the fuel control and the timing. This test monitors the number of high resolution pulses which have been missed (not detected). This test is based on a comparison between the number of pulses that were detected since the last pump cam pulse and the number of the pulses that should have occurred.