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

OPERATION

Power is supplied to the EGR cooler bypass control solenoid valve (terminal No. 2) from the engine control relay (terminal No. 1).
The engine-ECU (terminal No. 23) makes the power transistor in the unit be in "ON" position, and that makes currents go on the EGR cooler bypass control solenoid valve (terminal No. 1).

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. Connector check: B-111 EGR cooler bypass control solenoid valve connector, B-51 engine-ECU connector

Q. Are the check results normal?

	Go to Step 2 .

	Repair or replace the connector.

STEP 2. Check harness between B-111 (terminal No. 1) EGR cooler bypass control solenoid valve connector and B-51 (terminal No. 23) engine-ECU connector.

Check output line for short circuit.

Q. Is the check result normal?

	Go to Step 3 .

	Repair the damaged harness wire.

STEP 3. 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 ).