DTC Advanced Diagnostics: P050D
DTC P050D:Cold Start Ignition Timing Control System Performance Problem

General Description
The powertrain control module (PCM) monitors the ignition timing during the catalyst heating. To increase the energy within the exhaust system, the ignition timing must be shifted to retard. The task of the diagnosis function is to monitor the retard of the ignition timing. If the deviation of actual ignition efficiency comparing to the desired catalyst heating ignition efficiency is a specified value for a specified time during catalyst heating, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Once per driving cycle
Sequence
None
Duration
0.5 second or more
DTC Type
Two drive cycles, MIL on

Enable Conditions
Condition
Minimum
Maximum
Absolute difference of current and filtered engine speed
–
400 rpm
Charging efficiency
–
49.992 %
Other
Catalyst heating is active
Vehicle stopped
[ ]: HDS Parameter

Malfunction Threshold
The deviation of actual ignition efficiency comparing to the desired catalyst heating ignition efficiency is greater than 0.2 for at least 5 seconds during catalyst heating.

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
Ignition timing incorrect
Injection timing incorrect
Ignition coil failure
Injector failure

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool clear command.