P050B
DTC P050B: Cold Start Ignition Timing PerformanceCircuit Description
Ignition 1 voltage is supplied to the ignition coil. The engine control module (ECM) provides a ground for the ignition coil (IC) control circuits. When the ECM removes the ground path of the ignition primary coil, the magnetic field produced by the coil collapses. The collapsing magnetic field produces a voltage in the secondary coil which ignites the spark plugs. The sequencing and timing are controlled by the ECM. This DTC detects if the spark timing is either advanced or retarded beyond the threshold from the commanded spark timing.
Conditions for Setting the DTC
- Ignition voltage is between 10 and 16 V.
- Engine speed is greater than 450 rpm.
- Spark timing is either advanced or retarded from the commanded spark timing.
Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will illuminate.
- The ECM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records buffers.
- A history DTC is stored.
Conditions for Clearing the MIL/DTC
- The MIL will turn OFF after four consecutive ignition cycles in which the diagnostic runs without a fault.
- A history DTC will clear after 40 consecutive warm up cycles without a fault.
- The DTC(s) can be cleared by using the scan tool.
Troubleshooting
