Toyota Tundra Service Manual: Exhaust Gas Recirculation Control Circuit (P0403)

Toyota Tundra Service Manual / Engine, Hybrid System / 1ur-fe Engine Control / Sfi System / Exhaust Gas Recirculation Control Circuit (P0403)

DESCRIPTION

Refer to DTC P0401 (See page ).

DTC No.

DTC Detection Condition

Trouble Area

P0403

Open or short in EGR valve circuit

(1 trip detection logic)

  • Open or short in EGR valve circuit
  • EGR valve assembly
  • ECM

HINT:

DTC P0403 is set when the ignition switch is in the ON position.

MONITOR DESCRIPTION

This DTC is designed to detect an open or short in the EGR valve assembly circuit.

If the EGR terminal voltage is low when the EGR terminal output is off, the ECM determines that the EGR valve circuit is malfunctioning.

MONITOR STRATEGY

Related DTCs

P0403: Exhaust gas recirculation control circuit range check

Required Sensors/Components (Main)

EGR valve

Required Sensors/Components (Related)

-

Frequency of Operation

Continuous

Duration

1 second

MIL Operation

Immediate

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever following DTCs not present

None

Engine

Running

Battery voltage

10.5 V or higher

Starter

OFF

TYPICAL MALFUNCTION THRESHOLDS

One of the following conditions is met:

Condition 1, 2, 3 or 4

1: Both conditions are met:

Condition A and B

A: Motor phase 1 output terminal voltage

Low

B: Either condition is met:

-

Motor

Driving

Motor phase 1

Not operating

2: Both conditions are met:

Condition A and B

A: Motor phase 2 output terminal voltage

Low

B: Either condition is met:

-

Motor

Driving

Motor phase 2

Not operating

3: Both conditions are met:

Condition A and B

A: Motor phase 3 output terminal voltage

Low

B: Either condition is met:

-

Motor

Driving

Motor phase 3

Not operating

4: Both conditions are met:

Condition A and B

A: Motor phase 4 output terminal voltage

Low

B: Either condition is met:

-

Motor

Driving

Motor phase 4

Not operating

CONFIRMATION DRIVING PATTERN

  1. Connect the Techstream to the DLC3.
  2. Turn the ignition switch to ON and turn the Techstream on [A].
  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) (See page ).
  4. Start the engine and warm it up [B].
  5. Drive the vehicle at 20 km/h (12 mph) or more for 10 minutes [C].

    CAUTION:

    When performing the confirmation driving pattern, obey all speed limits and traffic laws.

  6. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [D].
  7. Read the pending DTCs.

    HINT:

    • If a pending DTC is output, the system is malfunctioning.
    • If a pending DTC is not output, perform the following procedure.
  8. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
  9. Input the DTC: P0403.
  10. Check the DTC judgment result.

    Techstream Display

    Description

    NORMAL

    • DTC judgment completed
    • System normal

    ABNORMAL

    • DTC judgment completed
    • System abnormal

    INCOMPLETE

    • DTC judgment not completed
    • Perform driving pattern after confirming DTC enabling conditions

    N/A

    • Unable to perform DTC judgment
    • Number of DTCs which do not fulfill DTC preconditions has reached ECU's memory limit

    HINT:

    If the judgment result shows ABNORMAL, the system has a malfunction.

  11. If the test result is INCOMPLETE or N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs (See page ).

    HINT:

    • If a permanent DTC is output, the system is malfunctioning.
    • If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

Refer to DTC P0401 (See page ).

CAUTION / NOTICE / HINT

HINT:

Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE

1.

PERFORM ACTIVE TEST USING TECHSTREAM (OPERATE EGR VALVE)

(a) Connect the Techstream to the DLC3.

(b) Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

HINT:

  • When performing the Active Test, make sure the shift lever is in P or N.
  • The A/C switch and all accessory switches should be off.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position.

(e) Confirm the Throttle Idle Position is ON and 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.

OK:

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

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 stall

MAP

(Data List)

20 to 40 kPa (150 to 300 mmHg)

MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed

OK

CHECK FOR INTERMITTENT PROBLEMS

NG

2.

INSPECT EGR VALVE ASSEMBLY

(a) Inspect the EGR valve assembly (See page ).

HINT:

Perform "Inspection After Repair" after replacing the EGR valve assembly (See page ).

NG

REPLACE EGR VALVE ASSEMBLY

OK

3.

INSPECT EGR VALVE ASSEMBLY (+B OR +B2 VOLTAGE)

(a) Disconnect the EGR valve assembly connector.

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

D85-5 (+B1) - Body ground

Ignition switch ON

11 to 14 V

D85-2 (+B2) - Body ground

Ignition switch ON

11 to 14 V

(c) Reconnect the EGR valve assembly connector.

NG

GO TO STEP 6

OK

4.

CHECK HARNESS AND CONNECTOR (ECM - EGR VALVE ASSEMBLY)

(a) Disconnect the EGR valve assembly connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Open):

Tester Connection

Condition

Specified Condition

D74-48 (EGR1) - D85-4 (EGR1)

Always

Below 1 Ω

D74-1 (EGR2) - D85-3 (EGR2)

Always

Below 1 Ω

D74-24 (EGR3) - D85-6 (EGR3)

Always

Below 1 Ω

D74-47 (EGR4) - D85-1 (EGR4)

Always

Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection

Condition

Specified Condition

D74-48 (EGR1) or D85-4 (EGR1) - Body ground

Always

10 kΩ or higher

D74-1 (EGR2) or D85-3 (EGR2) - Body ground

Always

10 kΩ or higher

D74-24 (EGR3) or D85-6 (EGR3) - Body ground

Always

10 kΩ or higher

D74-47 (EGR4) or D85-1 (EGR4) - Body ground

Always

10 kΩ or higher

(d) Reconnect the EGR valve assembly connector.

(e) Reconnect the ECM connector.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

5.

CHECK WHETHER DTC OUTPUT RECURS (DTC P0403)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON and turn the Techstream on.

(c) Clear DTCs (See page ).

(d) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.

(e) Confirm that no DTC is set using the Techstream.

Result

Result

Proceed to

DTC P0403 output

A

No DTC output

B

A

REPLACE ECM

B

END

6.

CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - EGR VALVE ASSEMBLY)

(a) Disconnect the EGR valve assembly connector.

(b) Remove the integration relay from engine room relay block.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for open):

Tester Connection

Condition

Specified Condition

2B-4 - D85-5 (+B1)

Always

Below 1 Ω

2B-4 - D85-2 (+B2)

Always

Below 1 Ω

Standard Resistance (Check for short):

Tester Connection

Condition

Specified Condition

2B-4 or D85-5 (+B1) - Body ground

Always

10 kΩ or higher

2B-4 or D85-2 (+B2) - Body ground

Always

10 kΩ or higher

(d) Reconnect the EGR valve assembly connector.

(e) Reinstall the integration relay.

OK

CHECK ECM POWER SOURCE CIRCUIT

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

    Exhaust Gas Recirculation Flow Insufficient Detected (P0401)

    Secondary Air Injection System Switching Valve "A" Circuit (P0412,P0415)

    See More:

    Toyota Tundra Service Manual > Can Communication System: Check Bus 1 Line for Short to GND
    DESCRIPTION There may be a short circuit between one of the CAN bus lines and GND when there is no resistance between terminal 23 (CA1H) of the central gateway ECU (network gateway ECU) and terminal 4 (CG) of the DLC3, or terminal 8 (CA1L) of the central gateway ECU (network gateway ECU) and termina ...

    Toyota Tundra Owners Manual

    Toyota Tundra Service Manual

    © 2021 Copyright www.ttundra.com
    0.0209