P0403

DTC P0403: Exhaust Gas Recirculation (EGR) Control Circuit

Wiring Diagram










DTC Detecting Condition and Trouble Area






DTC Confirmation Procedure

WARNING:

- When performing a road test, select a place where there is no traffic or possibility of a traffic accident and be very careful during testing to avoid occurrence of an accident.
- Road test should be carried out with 2 persons, a driver and a tester, on a level road.

NOTE:

Make sure that the following conditions are satisfied when using this DTC confirmation procedure.

- Intake air temp.: Between -10 °C (14 °F) or more

1) With ignition switch turned OFF, connect scan tool to DLC.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and warm it up to normal operating temperature.
4) Drive vehicle in 2000 - 3500 rpm of engine speed for 10 minutes or more.
5) Keep the vehicle speed for 10 min. (Throttle valve opening is kept constant in this step.)
6) Stop vehicle and check DTC and pending DTC.

DTC Troubleshooting

1.
Was "Engine System Check" performed?
YES
Go to Step 2.
NO
Go to Engine System Check Engine System Check.

2. EGR valve power supply circuit check.

With ignition switch turned OFF, disconnect EGR valve coupler.
With ignition switch turned ON, check voltage between "BLK/RED" wire terminals of EGR valve coupler and body ground.

Is check voltage 10 - 14 V?
YES
Go to Step 5.
NO
Faulty "BLK/RED" wire.

3. Check wire circuit.

Disconnect connectors from ECM with ignition switch turn OFF.
Turn ON ignition switch.
Measure voltage between engine ground and each "GRY", "GRY/WHT", "GRY/YEL", "BRN/WHT" wire terminal.

Is each voltage 0 V?
YES
Go to Step 4.
NO
Some wire shorted to other circuits.
If wires are OK, substitute a known-good ECM and recheck.

4. Check wire circuit.

With ignition switch turned OFF, measure resistance between engine ground and each "GRY", "GRY/WHT", "GRY/YEL", "BRN/WHT" wire terminal.

Is resistance infinity?
YES
Go to Step 5.
NO
Some wire shorted to ground circuit.
If wires are OK, substitute a known-good ECM and recheck.

5. EGR valve stepper motor coil circuit check.

With ignition switch turned OFF, connect EGR valve coupler couplers.
Check resistance between "G04-8 (or 23)" and "C46-3", "C46-13", "C46-14", "C46-15".

Is each resistance 20 - 24 ohms at 20 °C, 68 °F?
YES
Faulty ECM substitute a known-good ECM and recheck.
NO
Go to Step 6.

6. Check wire circuit.

Turn ON ignition switch.
Measure voltage between engine ground and each "GRY", "GRY/WHT", "GRY/YEL", "BRN/WHT" wire terminal.

Is each voltage 10 - 14 V?
YES
Some wire in high resistance circuit.
If wires are good condition, faulty EGR valve.
NO
Some wire open circuit.
If wires are good condition, faulty EGR valve.