Code No. P2427: EGR Cooling Valve Control Circuit (High)


OPERATION



  • Power is supplied to the EGR cooler bypass control solenoid valve connector terminal from the engine control relay connector terminal.
  • The engine-ECU connector terminal EGC makes the power transistor in the unit be in "ON" position, and that makes currents go on the EGR cooler bypass control solenoid valve connector terminal.

FUNCTION



  • By the signals from the engine-ECU, the EGR cooler bypass control solenoid valve takes control switching the pressure in the vacuum pump between the vacuum pressure and the atmospheric pressure.

TROUBLE JUDGMENT


Check Conditions
  • 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.
Judgment Criterion
  • When the ECU command is "CLOSED" and the valve position judged by the terminal voltage is "OPEN".

FAIL-SAFE AND BACKUP FUNCTION



  • The EGR control is stopped (fully closed).

PROBABLE CAUSES



  • Failed engine-ECU
  • Short circuit or harness damage in EGR cooler bypass control solenoid valve circuit or loose connector contact

DIAGNOSIS PROCEDURE

STEP 1. Check harness between EGR cooler bypass control solenoid valve connector terminal and engine-ECU connector terminal EGC.

  • Check output line for short circuit.

Q. Is the check result normal?
Go to Step 2.
Repair or replace the connector, or repair the damaged harness wire.

STEP 2. M.U.T.-III diagnosis code



  • Reconfirmation of diagnosis code.

Q. Is the diagnosis code set?
Replace the engine-ECU.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).