Code No. P0122: Throttle Position Sensor (Main) Circuit Low Input <4A9>

OPERATION

• A power voltage of 5 V is applied to the electronic-controlled throttle valve (terminal No. 5) from the engine-ECU or engine-A-M/T-ECU (terminal No. 31).
  
• The power voltage is earthed to the engine-ECU or engine-A-M/T-ECU (terminal No. 30) from the electronic-controlled throttle valve (terminal No. 3).
  
• The sensor signal is inputted to the engine-ECU or engine-A-M/T-ECU (terminal No. 15) from the electronic-controlled throttle valve output terminal (terminal No. 4).
  

FUNCTION

• The throttle position sensor converts the throttle valve position into voltage and inputs it into the engine-ECU or engine-A-M/T-ECU.
  
• The engine-ECU or engine-A-M/T-ECU controls the throttle valve position.
  

TROUBLE JUDGMENT

• Ignition switch is in "ON" position.
  

• Throttle position sensor (main) output voltage is 0.35 V or less for 0.5 second.
  

PROBABLE CAUSES

• Failed throttle position sensor (main)
  
• Open or shorted throttle position sensor (main) circuit, harness damage, or connector damage
  
• Failed engine-ECU or engine-A-M/T-ECU
  

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

	Go to Step 2 .

Q. Are the check results normal? Go to Step 3 . Repair or replace the connector.

Check power supply line for damage. Q. Is the check result normal? Go to Step 4 . Repair the damaged harness wire.

Check output line for short circuit. Q. Is the check result normal? Go to Step 5 . Repair the damaged harness wire.

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

	Go to Step 6 .

	Replace the engine-ECU or engine-A-M/T-ECU then perform the variant coding (Refer to GROUP 00 - Precautions Before Service - How to Perform Variant Coding ).

	Check end.