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Home >> Toyota >> 2013 >> Prius Plug-in >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System (Diagnostic Codes ( P0327 - P1422)) (Plug-In) >> SFI System >> DTC P050B: Cold Start Ignition Timing Performance >> Monitor Description
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Monitor Description

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 is stored 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 less than 50°C (122°F), the ECM checks the ignition timing during 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 stored when the malfunction is detected in consecutive driving cycles (2 trip detection logic).

NOTE:

When the negative (-) auxiliary battery terminal is disconnected during inspection or repairs, the idle speed control learned values are cleared. Idle speed control learning needs to be performed before this DTC can be stored. To perform idle speed control learning, the engine must be warmed up by allowing it to idle for 5 minutes. For idle speed control learning to be successful, when the engine is started to warm it up, there must be at least 10 seconds of idling with the coolant temperature less than 50°C (122°F) before allowing it to continue running for the 5 minute learning period.

Fig 1: Identifying P050B Detection Logic
GTY315796Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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 sub-assembly
  • PCV system
  • Air cleaner filter element sub-assembly
  • Intake system
  • VVT system
  • EGR valve assembly
  • Wire harness or connector
  • ECM