DTC P050B: Cold Start Ignition Timing Performance: Description

DTC DETECTION CONDITION CHART

DTC No.	DTC Detection Condition	Trouble Area
P050B	Insufficient ignition timing retard at cold start (2 trip detection logic)	Throttle body Mass air flow meter PCV hose Air cleaner filter Air induction system VVT system ECM

This monitor will run when the engine is started with the engine coolant temperature at -10 to 50°C (14 to 122°F). The DTC will be set after the engine idles for 13 seconds (2 trip detection logic).

The DTC is designed to monitor the ignition timing at cold start. When the engine is started with the engine coolant temperature at lower than 50°C (122°F), the ECM (PCM) checks the ignition timing at the engine idling. If the ignition timing advances beyond the criteria within 10 seconds, the ECM (PCM) interprets this as a malfunction. The MIL is illuminated and a DTC is set when the malfunction is detected in consecutive driving cycles (2 trip detection logic).

NOTE: When the negative battery terminal is disconnected during inspections or repairs, the ISC (Idle Speed Control) learning values are cleared. This DTC cannot be set with the ISC learning values cleared.
The ISC learning is performed when the engine is warmed up and has been idling for 5 minutes.

Fig 1: Engine Coolant Temperature Graph