DTC P0401 Exhaust Gas Recirculation Flow Insufficient Detected

Transcription

1 DIAGNOSTICS DI95 DI07W03 DTC P040 Exhaust Gas Recirculation Flow Insufficient Detected CIRCUIT DESCRIPTI The EGR system recirculates exhaust gas, which is controlled to the proper quantity to suit the driving conditions, into the intake air mixture to slow down combustion, reduce the combustion temperature and reduce NOx emissions. The lift amount of EGR valve is controlled by the vacuum which is regulated by the DutyVSV operated by the. The lift amount of EGR valve is detected by the EGR valve position sensor which is mounted on the EGR valve and it provides feedback to the to control the lift amount of EGR valve in response to engine operating conditions. Under the following conditions, EGR is cut to maintain driveability. Before the engine is warmed up During deceleration (throttle valve closed) Light engine load (amount of intake air very small) Engine speed over 4,000 rpm Engine idling Mass Air Flow Meter Vacuum Control Valve Throttle Valve Intake Air Chamber VSV for EGR Engine Coolant Temp. Sensor EGR Valve Position Sensor EGR Gas Temp. Sensor EGR Valve Crankshaft Position Sensor A0099 DTC No. DTC Detecting Condition Trouble Area P040 After the engine is warmed up and run at 80 km/h (50 mph) for 3 to 5 min. the EGR gas temperature sensor valve does not exceed 35 C (95 F) above the ambient air temperature ( trip detection logic) EGR valve (stuck closed) Open or short in EGR gas temp. sensor circuit EGR gas temp. sensor Open in VSV circuit for EGR VSV for EGR Vacuum control valve Vacuum hose disconnected or blocked 48

2 DI96 DIAGNOSTICS WIRI DIAGRAM F8 B F0 B H Fusible Link Block Engine Room J/B 7 EFI B 5 3 EFI Relay 3 C D BO J3 Junction Connector LG LG BW A A VSV for EGR 3 LR RW BR 8 (*) (*) (*) 8 (*) (*) 5 (*) EGR E0 5V VC EGLS E FL MAIN Battery WB EB EGR Gas Temp. Sensor EGR Valve Position Sensor 6 BO BO IK GY BR (*) 3 8 (*) (*) 8 E (*) 4 (*) MREL E 5V E A

3 DIAGNOSTICS DI97 SYSTEM CHECK DRIVI PATTERN Vehicle Speed km/h (43 56 mph) (3) (5) Idling IG SW OFF () () Warmed up 3 5 min. 3 min. 3 5 min. min. (4) Time S06906 () Connect the OBD II scan tool or TOYOTA handheld tester to the DLC3. () Start and warm up the engine with all accessories switched OFF. (3) Run the vehicle at km/h (43 56 mph) for 3 min. or more. (4) Idle the engine for about min. (5) Do steps (3) and (4) again. (6) Stop at safe place and turn the ignition switch OFF. (7) Do step () to (5) again. (8) Check the READINESS TESTS mode on the OBD II scan tool or TOYOTA handheld tester. If COMPL is displayed and the MIL does not light up, the system is normal. If INCMPL is displayed and the MIL does not light up, run the vehicle steps () to (6) from some times and check it. HINT: INCMPL is displayed when either condition (a) or (b) exists. (a) The system check is incomplete. (b) There is a malfunction in the system. If there is a malfunction in the system, the MIL light up after step (7) above is done again. (trip detection logic) INSPECTI PROCEDURE HINT: Read freeze frame data using TOYOTA handheld tester or OBD II scan tool. Because freeze frame records the engine conditions when the malfunction is detected, when troubleshooting it is useful for detrmining whether the vehicle was running or stopped, the engine warmed up or not, the airfuel ratio lean or rich, etc. at the time of the malfunction. 50

4 DI98 DIAGNOSTICS TOYOTA handheld tester Connect TOYOTA handheld tester and read value of EGR gas temperature. (a) Connect the TOYOTA handheld tester to the DLC3. (b) Warm up the engine. Read EGR gas temperature on TOYOTA handheld tester during idling. : EGR gas temperature : 0 C (50 F) 50 C (30 F) (Not immediately after driving) HINT: If there is an open circuit, TOYOTA handheld tester indicates 3. C (37.6 F). If there is an short circuit, TOYOTA handheld tester indicates 59.3 C (38.7 F). Go to step 4. Check for open or short in harness or. B653 A036 A036 B653 EGR Gas Temp. Sensor EGR Gas Temp. Sensor E (*) (*) E (*) (*) 5V *: Except California, w/engine Immobiliser and/or TRAC. *: California, w/engine Immobiliser and/or TRAC. 5V A0370 For open circuit (a) Disconnect the EGR gas temp. sensor connector. (b) Connect the sensor wire harness terminals together. (c) Turn the ignition switch. Read EGR gas temperature on the TOYOTA handheld tester. : EGR gas temperature : 59.3 C (38.7 F) For short circuit Disconnect the EGR gas temp. sensor connector. Read EGR gas temperature on the TOYOTA handheld tester. : EGR gas temp. : 3. C (37.6 F) Confirm good connection at sensor. If, check and replace EGR gas temp. sensor. 5

5 DIAGNOSTICS DI99 3 Check for open or short in harness or. *: Except California, w/engine Immobiliser and/or TRAC. *: California, w/engine Immobiliser and/or TRAC. EGR Gas Temp. Sensor E (*) (*) Except California, w/engine Immobiliser and/or TRAC. 5V For open circuit (a) Remove the glove compartment (See page SF69 ). (b) Connect between terminals and E of the connectors. HINT: EGR gas temp. sensor connector is disconnected. Before checking, do a visual check and contact pressure check for the connector (See page IN30 ). Read EGR gas temperature on the TOYOTA handheld tester. : EGR gas temperature : 59.3 C (38.7 F) E California, w/engine Immobiliser and/or TRAC. B653 A0358 P3869 A0368 E A0368 5

6 DI00 DIAGNOSTICS EGR Gas temp. Sensor Except California, w/engine Immobiliser and/or TRAC. E For short circuit (a) Remove the glove compartment (See page SF69 ). (b) Disconnect the connector (Except California, w/engine immobiliser and/or TRAC.), connector (California, w/engine immobiliser and/or TRAC.) of. Read EGR gas temperature on the TOYOTA handheld tester. : EGR gas temperature: 3. C (37.6 F) California, w/engine Immobiliser and/or TRAC. B653 F7099 F705 A04054 A047 Repair or replace harness. Confirm connection at. If, check and replace. 4 Check connection and blockage of vacuum hose (See page EC ). Repair or replace vacuum hose. 53

7 DIAGNOSTICS DI0 5 Check VSV for EGR. B653 A0507 F VSV is Air E G F Air E VSV is OFF G A0839 Select the ACTIVE TEST mode on the TOYOTA handheld tester. Check operation VSV, when it is operated by the TOYOTA handheld tester. : VSV is : Air from pipe E is flowing out through pipe F and G. VSV is OFF: Air from pipe E is flowing out through pipe G. Go to step 8. 6 Check operation of VSV for EGR (See page SF5 ). Replace VSV for EGR. Check for open in harness and connector between engine room J/B and. 7 Check EGR system (See page EC7 ). Repair or replace. 54

8 DI0 DIAGNOSTICS 8 Check EGR valve. Vacuum EGR Valve S0540 (a) Disconnect the vacuum hose from EGR valve. (b) Start the engine. Check whether the engine stall when apply vacuum to EGR valve. : Engine runs rough or stall. Repair or replace EGR valve. 9 Check vacuum control valve (See page EC7 ). Replace vacuum control valve. Check and replace (See page IN30 ). 55

9 DIAGNOSTICS OBDII scan tool (excluding TOYOTA handheld tester) DI03 Check resistance of EGR gas temp. sensor. EGR Gas Temp. Sensor Connector P387 Disconnect the EGR gas temp. sensor connector. Measure resistance between terminals of the EGR gas temp. sensor connector. : Resistance:.5 kω 600 kω (Not immediately after driving) HINT: If there is open circuit, ohmmeter indicates 70 kω or more. If there is short circuit, ohmmeter indicates 00 Ω or less. Replace EGR gas temp. sensor. Check for open and short in harness and connector between EGR gas temp. sensor and (See page IN30 ). Repair or replace harness or connector. 3 Check connection and blockage of vacuum hose (See page EC ). Repair or replace vacuum hose. 56

10 DI04 DIAGNOSTICS 4 Check VSV for EGR. Except California, w/engine Immobiliser and/or TRAC. EGR OFF California, w/engine Immobiliser and/or TRAC. (a) Remove the glove compartment (See page SF69 ). (b) Disconnect the connector (Except California, w/engine immobiliser and/or TRAC.) connector (California, w/engine immobiliser and/or TRAC.) of. (c) Turn the ignition switch. Check VSV function. () Connect between terminal EGR of the and body ground (VSV is ). () Disconnect between terminal EGR of the and body ground (VSV is OFF). : () VSV is : Air from pipe E flows out through pipe F. () VSV is OFF: Air from pipe E flows out through pipe G. EGR OFF Go to step 7. VSV is VSV is OFF B653 P3874 A0369 S0498 F S0499 Air E G F Air E G A048 57

11 DIAGNOSTICS DI05 5 Check operation of VSV for EGR (See page SF5 ). Replace VSV for EGR. Check for open in harness and connector between engine room J/B and. 6 Check EGR system (See page EC7 ). Repair or replace. 7 Check EGR valve (See page DI95, step 7). Repair or replace EGR valve. 8 Check vacuum control valve (See page EC7 ). Replace vacuum control valve. Check and replace (See page IN30 ). 58