DTC P0403: Exhaust Gas Recirculation Control Circuit: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Turn the Techstream on.
4. Put the engine in inspection mode (maintenance mode). Refer to INSPECTION MODE PROCEDURE .
5. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

   HINT: 

   The A/C switch and all accessory switches should be off.

6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / Data List / Primary / MAP.
7. Check the engine idling condition and MAP values in the Data List while performing the Active Test.

   HINT: 

   • Do not leave the EGR valve open for 10 seconds or more during the Active Test.
   • Be sure to return the EGR valve to step 0 when the Active Test is completed.
   • Do not open the EGR valve 30 steps or more during the Active Test.

   OK

   MAP and idling condition change in response to EGR step position.

   Standard

   -	EGR Step Position (Active Test)
   	0 Steps	0 to 30 Steps
   Idling condition	Steady idling	Idling changes from steady to rough idling or engine stalls
   MAP (Data List)	MAP value is 20 to 40 kPa(abs) [150 to 300 mmHg(abs)] (EGR valve is fully closed)	MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed

   HINT: 

   During Active Test, if the idling condition does not change in response to EGR step position, then there is probably a malfunction in the EGR valve.

NG → See step   2 

OK → See step   5 

1. Inspect the EGR valve assembly. Refer to INSPECTION .

NG → See step   6 

OK: Go to next step 

1. Disconnect the EGR valve assembly connector.
   Fig 1: Checking D10 Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Turn the power switch on (IG).
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   D10-2 (+B1) - Body ground	Power switch on (IG)	11 to 14 V
   D10-5 (+B2) - Body ground	Power switch on (IG)	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to EGR Valve Assembly)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (EGR VALVE ASSEMBLY - EFI MAIN RELAY) 

OK: Go to next step 

1. Disconnect the EGR valve assembly connector.
2. Disconnect the ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   D10-4 (EGR1) - D28-45 (EGR1)	Always	Below 1 Ω
   D10-3 (EGR2) - D28-44 (EGR2)	Always	Below 1 Ω
   D10-6 (EGR3) - D28-43 (EGR3)	Always	Below 1 Ω
   D10-1 (EGR4) - D28-42 (EGR4)	Always	Below 1 Ω
   D10-4 (EGR1) or D28-45 (EGR1) - Body ground	Always	10 kΩ or higher
   D10-3 (EGR2) or D28-44 (EGR2) - Body ground	Always	10 kΩ or higher
   D10-6 (EGR3) or D28-43 (EGR3) - Body ground	Always	10 kΩ or higher
   D10-1 (EGR4) or D28-42 (EGR4) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   7