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Home >> Lexus >> 2013 >> RX 350 Base, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostic Codes (P0505 - P1603)) >> SFI System >> DTC P050B: Cold Start Ignition Timing Performance (03/2012 - 07/2012) >> 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 battery terminal is disconnected during inspection or repairs, the idle speed control learned values are cleared. idle speed control learning is performed when the engine has been warmed up and idled for 5 minutes because this DTC cannot be set after the idle speed control learned values are cleared.

HINT: 

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

Fig 1: DTC Detection Logic Graph
GTY406754Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
DTC No. DTC Detection Condition Trouble Area
P050B Insufficient ignition timing retard and cold start (2 trip detection logic)
  • Throttle with motor body assembly
  • Mass air flow meter sub-assembly
  • Intake system
  • PCV system
  • VVT system
  • Air cleaner filter element sub-assembly
  • Wire harness or connector
  • ECM