DTC Advanced Diagnostics: P050B (3.0L Engine)
DTC P050B: Cold Start Ignition Timing Control System Performance Problem
General Description
The quick warm-up system increases airflow and retards ignition timing to accelerate the warm-up of the catalyst on cold engine start. The powertrain control module (PCM) compares the output ignition timing with the requested ignition timing during the quick warm-up. If the output ignition timing deviates from the requested ignition timing, the powertrain control module (PCM) detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 10 seconds or more |
| DTC Type | Two drive cycles, MIL on |
Enable Conditions
| Condition | |
|---|---|
| Quick warm-up | On |
Malfunction Threshold
Output ignition timing - (minus) requested ignition timing is more than +10 deg., or less than -10 deg. for at least 10 seconds.
Possible Cause
- Ignition system failure
Confirmation Procedure
Operating Condition
- Leave the vehicle until the engine coolant temperature [ECT Sensor 1] lowers to 86 deg.F (30 deg.C) or less.
- Start the engine, and let it idle for at least 15 seconds.
[ ]: HDS Parameter
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, the freeze data, and the on-board snapshot 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, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.