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DTC P050B: Ignition Timing Retard Insufficient
 
 
 
 
TECHNICAL DESCRIPTION
  • After starting the engine in the cold state, the ECM retards the ignition timing to early activate the catalyst by letting out the high temperature exhaust gases.
  • The ECM monitors whether the retard ignition timing control is normal or not.
 
 
DESCRIPTIONS OF MONITOR METHODS
  • After starting the engine in the cold state, the retard ignition timing control is abnormal.
 
 
MONITOR EXECUTION
  • Once per driving cycle
 
 
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC set in memory for the item monitored below)
  • Not applicable
Sensor (The sensor below is determined to be normal)
  • Not applicable
 
 
DTC SET CONDITIONS
Logic Flow Chart
 
 
Check Conditions
  • Under the ignition timing retard control.
  • Engine coolant temperature is between 7°C (45°F) and 42°C (108°F).
Judgment Criterion
  • For 10 seconds, the target/specified ignition timing subtracted from the basic ignition timing is less than 3 degrees on average during the retard control.
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • None
 
 
OBD-II DRIVE CYCLE PATTERN
  • Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 2 .
 
 
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
  • Dirtiness around throttle valve.
  • ECM failed.

 
 
DIAGNOSIS
STEP 1. Check the throttle body. (throttle valve area)
Is the throttle valve area dirty?
Perform cleaning. Refer to Throttle body (throttle valve area) cleaning . Then go to Step 3.
Repair it. Then go to Step 2.
 
STEP 2. Using scan tool (M.U.T.-IIISE), read the diagnostic trouble code (DTC).
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn off the power supply mode of the electric motor switch before connecting or disconnecting scan tool (M.U.T.-IIISE).
(1) Connect scan tool (M.U.T.-IIISE). Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-IIISE) .
(2) Turn on the power supply mode of the electric motor switch.
(3) After the DTC has been deleted, read the DTC again.
(4) Turn off the power supply mode of the electric motor switch.
Is DTC P050B set?
Replace the ECM (Refer to Removal and Installation ). Then go to Step 3.
It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions .
 
STEP 3. Test the OBD-II drive cycle.
(1) Carry out test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 2 .
(2) Check the diagnostic trouble code (DTC).
Is DTC P050B set?
Retry the troubleshooting.
The inspection is complete.