This monitor will run when the engine is started at an engine coolant temperature of-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 at an engine coolant temperature of lower than 50°C (122°F), the ECM checks the ignition timing at engine idling. If the ignition timing advances beyond the specified level within 10 seconds, the ECM interprets this as a malfunction. The MIL is illuminated and a DTC is set when the malfunction is detected in consecutive driving cycles (2 tip 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.

HINT:

The ISC learning is performed when the engine is warmed up and has been idling for 5 minutes.

Fig 1: Cold Start Ignition Timing Performance Graph

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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 assembly Mass air flow meter PCV system Air cleaner filter element Air induction system VVT system ECM

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

DTC P050B Cold Start Ignition Timing Performance: Description

Use the Manual With the Right Hardware

When to See a Mechanic

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