Code No. P0490: EGR Valve Position Sensor Circuit High Input

OPERATION

• A power voltage of 5 V is applied to the EGR valve assembly power terminal from the engine-ECU connector terminal EGR5 and earthed to the engine-ECU connector terminal EGRE from the EGR valve assembly connector terminal.
  
• The sensor signal is inputted to the engine-ECU connector terminal EGRP from the EGR valve assembly output terminal.
  

FUNCTION

• The EGR valve assembly detects the position of the EGR valve and sends the signal to the engine-ECU.
  
• Based on the signal, the engine-ECU performs the feedback control of the EGR valve.
  

TROUBLE JUDGEMENT

• Battery positive voltage is 8 - 16 V
  
• 2 seconds later after the ignition switch has been in "ON" position or the engine has started up.
  

• The EGR valve position sensor output voltage is 4.80 V or more.
  

FAIL-SAFE AND BACKUP FUNCTION

• The DPF regeneration is prohibited.
  
• The throttle valve is opened (electrical discontinuity).
  
• The EGR control is stopped (fully closed).
  

PROBABLE CAUSES

• Failed EGR valve position sensor
  
• Open circuit or harness damage in EGR valve position sensor circuit or loose connector contact
  
• Failed engine-ECU
  

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

	Go to Step 2.

	Go to Step 5.

	Go to Step 3.

	Go to Step 4.

	Repair the connector(s) or wiring harness.

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

	Replace the engine-ECU.

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

	Replace the EGR valve assembly.