DTC P0401 Exhaust Gas Recirculatin Flw Insufficient Detected DESCRIPTION Based n the driving cnditins, the ECM regulates the vlume f exhaust gas that is recirculated t the engine's cmbustin chambers and thus lwers the cmbustin temperature t reduce NOx emissins. The ECM mnitrs signals such as engine speed, clant temperature, electric lad, and vehicle speed. When the EGR permissin cnditins are fulfilled, the ECM cntrls the pening f the EGR valve linearly thrugh signals t the EGR step mtr. DTC N. DTC Detectin Cnditin Truble Area P0401 Change in intake manifld pressure is small when the EGR valve is pened and clsed during idle fuel cut peratin. (2 trip detectin lgic) EGR valve assembly EGR passage EGR with cler pipe subassembly Manifld abslute pressure sensr ECM MONITOR DESCRIPTION The ECM mnitrs the pressure inside the intake manifld while pening and clsing the EGR valve during fuel cut peratin. If there is n change in the manifld abslute pressure sensr value, the ECM interprets this as a malfunctin in the EGR valve assembly, illuminates the MIL and stres the DTC (2 trip detectin lgic). MONITOR STRATEGY Related DTC Required sensrs / cmpnents (Main) Required sensrs / cmpnents (Related) Frequency f peratin Duratin MIL peratin Sequence f peratin P0401: EGR valve high flw rate / lw flw rate EGR valve assembly, manifld abslute pressure sensr Engine clant temperature sensr, vehicle speed sensr Cntinuus 3 secnds 2 driving cycles Nne TYPICAL ENABLING CONDITIONS Mnitr runs whenever fllwing DTCs are nt present Time after engine started Time after engine fuel cut Engine speed Vehicle speed Nne 3 secnds r mre 2000 msec r mre 950 t 1600 rpm 12.5 mph (20 km/h) r mre
Engine speed change Time after engine lad becmes stable (HVAC, Brake, Lckup) Engine clant temperature Battery vltage Intake air temperature Atmspheric pressure -20 t 20 rpm Mre than 1.2 sec 70 C (158 F) r mre 11 V r mre -10 C (14 F) r mre 76 kpa r mre TYPICAL MALFUNCTION THRESHOLDS Manifld pressure change At engine speed Less than 1.0 kpa 1050 rpm CONFIRMATION DRIVING PATTERN 1. Cnnect the Techstream t the DLC3. 2. Turn the pwer switch n (IG) and turn the Techstream n. 3. Clear the DTCs (even if n DTCs are stred, perfrm the clear DTC prcedure). 4. Turn the pwer switch ff and wait fr 30 secnds. 5. Turn the pwer switch n (IG) and turn the Techstream n [A]. 6. Put the engine in inspectin mde. 7. Start the engine and warm it up until the engine clant temperature reaches 70 C (158 F) r mre [B]. The A/C switch and all accessry switches shuld be ff and shift lever in P r N. 8. Drive the vehicle at 25 t 37 mph (40 t 60 km/h) fr 5 minutes r mre [C]. 9. Idle the engine fr 30 secnds r mre [D].
10. Accelerate the vehicle t 25 t 37 mph (40 t 60 km/h) with the shift lever in B [E]. 11. Perfrm fuel cut peratin fr 5 secnds r mre, with the acceleratr pedal fully released [F]. CAUTION: When perfrming the cnfirmatin driving pattern, bey all speed limits and traffic laws. When fuel cut is perating "Idle Fuel Cut" in Data List is ON. 12. Enter the fllwing menus: Pwertrain / Engine and ECT / Mnitr / Exhaust Gas Recirculatin/VVT / Status2 [G]. 13. Check that the Exhaust Gas Recirculatin/VVT / Status2 mnitr is Cmplete. If the mnitr is Incmplete, perfrm the driving pattern again. 14. Enter the fllwing menus: Pwertrain / Engine and ECT / Mnitr / Exhaust Gas Recirculatin/VVT/Details. 15. Check the Details (EGR FLOW INSUFFICIENCY). Make sure that the value is between MIN and MAX. 16. If the mnitr is still Incmplete, perfrm the fllwing prcedure. 17. Enter the fllwing menus: Pwertrain / Engine and ECT / Truble Cdes / Pending. 18. Read Pending DTCs. 19. If a pending DTC is utput, the system is malfunctining, If a pending DTC is nt utput, perfrm the fllwing prcedure. 20. Enter the fllwing menus: Pwer train / Engine and ECT / Utility / All Readiness. 21. Input the DTC: P0401. 22. Check the DTC judgment result. Techstream Display NORMAL ABNORMAL DTC judgment cmpleted System nrmal DTC judgment cmpleted System abnrmal Descriptin INCOMPLETE DTC judgment nt cmpleted
Techstream Display UNKNOWN Descriptin Perfrm driving pattern after cnfirming DTC enabling cnditins Unable t perfrm DTC judgment Number f DTCs which d nt fulfill DTC precnditins has reached ECU's memry limit If the judgment result shws ABNORMAL, the system has a malfunctin. If the judgement result shws NORMAL, the system is nrmal. If the DTC judgment result is INCOMPLETE r UNKNOWN and n pending DTC is utput, accelerate the vehicle again at 25 t 37 mph (40 t 60 km/h) with the shift lever in B, perfrm fuel cut peratin fr 5 secnds r mre with the acceleratr pedal fully released, and check the DTC judgment result. 23. If the test result is INCOMPLETE r UNKNOWN and n pending DTC is utput, perfrm a universal trip and check fr permanent DTCs. If a permanent DTC is utput, the system is malfunctining. If n permanent DTC is utput, the system is nrmal. INSPECTION PROCEDURE By using the Cntrl the EGR Step Psitin Active Test, the peratin f the EGR valve can be checked. When the engine is idling steadily with the EGR valve fully clsed, if the EGR valve is nrmal and it is pened using the Active Test, the Data List value changes as fllws. Data List Engine Speed MAP Change in Data List when Number f Steps is Increased Using Cntrl the EGR Step Psitin Active Test Idle becmes rugh Pressure rises Read freeze frame data using the Techstream. The ECM recrds vehicle and driving cnditin infrmatin as freeze frame data the mment a DTC is stred. When trubleshting, freeze frame data can help determine if the vehicle was mving r statinary, if the engine was warmed up r nt, if the air fuel rati was lean r rich, and ther data frm the time the malfunctin ccurred. PROCEDURE
1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO P0401) (a) Cnnect the Techstream t the DLC3. (b) Turn the pwer switch n (IG). (c) Turn the Techstream n. (d) Enter the fllwing menus: Pwertrain / Engine and ECT / Truble Cdes. (e) Read the DTC. Result: Result DTC P0401 is utput DTC P0401 and ther DTCs are utput B GO TO DTC CHART A Prceed t A B 2. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE EGR STEP POSITION) (a) Cnnect the Techstream t the DLC3. (b) Turn the pwer switch n (IG). (c) Turn the Techstream n. (d) Put the engine in inspectin mde. (e) Start the engine and warm it up until the engine clant temperature reaches 75 C (167 F) r mre. The A/C switch and all accessry switches shuld be ff and shift lever in P r N. (f) Enter the fllwing menus: Pwertrain / Engine and ECT / Active Test / Cntrl the EGR Step Psitin. (g) Cnfirm the Thrttle Idle Psitin is ON and check the engine idling cnditin and MAP values in the Data List while perfrming the Active Test. D nt leave the EGR valve pen fr 10 secnds r mre during the Active Test. Be sure t return the EGR valve t step 0 when the Active Test is cmpleted. D nt pen the EGR valve 30 steps r mre during the Active Test. OK:
MAP and idling cnditin change in respnse t EGR step psitin as fllws. Standard: - Idling cnditin MAP (Data List) EGR Step Psitin (Active Test) 0 Steps 0 t 30 Steps Steady idling - Idling changes frm steady t rugh idling r engine stalls MAP value is at least +10 kpa (75 mmhg) higher than when EGR valve is fully clsed During Active Test, if the idling cnditin des nt change in respnse t EGR step psitin, then there is prbably a malfunctin in the EGR valve. Result: Result Outside f standard range Within standard range NG REPLACE EGR VALVE ASSEMBLY OK A B Prceed t 3. INSPECT EGR VALVE ASSEMBLY (a) Check if the EGR valve are clgged with depsits. (b) Check if the EGR valve is clsed. OK: EGR valve is clsed and n depsits. Result: Result Prceed t NG A OK B B CHECK FOR DEPOSIT (INTAKE PORT TO EGR VALVE ASSEMBLY) A 4. REPLACE EGR VALVE ASSEMBLY (a) Replace the EGR valve assembly.
NEXT 5. CHECK FOR DEPOSIT (INTAKE PORT TO EGR VALVE ASSEMBLY) (a) Check fr exhaust leaks at each cnnectin pint. (b) Check fr cracks, damage, and clgs in the pipes between the intake manifld and the EGR valve assembly. (c) This check may require the remval f cmpnents. (d) Check if there is a built-up f depsits in the EGR valve f pipes. OK: N depsits. NG REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA OK 6. CHECK FOR DEPOSIT (EXHAUST MANIFOLD SUB-ASSEMBLY TO EGR VALVE ASSEMBLY)
(a) Check fr exhaust leaks at each cnnectin pint. (b) Check fr cracks, damage, and clgs in the pipes between the exhaust manifld sub-assembly and the EGR valve assembly. (c) This check may require the remval f cmpnents. (d) Check if there is a built-up f depsits in the EGR valve f pipes. OK: N depsits. NG REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA OK 7. INSPECT EGR WITH COOLER PIPE SUB-ASSEMBLY (a) Check fr blckage f the EGR with cler pipe sub-assembly. NG REPAIR OR REPLACE EGR WITH COOLER PIPE SUB-ASSEMBLY
OK 8. READ VALUE USING TECHSTREAM (MANIFOLD ABSOLUTE PRESSURE SENSOR) (a) Cnnect the Techstream t the DLC3. (b) Turn the pwer switch n (IG). (c) Turn the Techstream n. (d) Enter the fllwing menus: Pwertrain / Engine and ECT / Data List / MAP. (e) Read the MAP value. Standard: Switch Cnditin Pwer switch n (IG) Techstream Display 80 t 110 kpa (600 t 825 mmhg) (f) Put the engine in inspectin mde. (g) Start the engine and warm it up until the engine clant temperature reaches 75 C (167 F) r mre. (h) Enter the fllwing menus: Pwertrain / Engine and ECT / Data List / MAP. (i) Read the MAP value when idling the engine with the A/C switch and all accessry switches shuld be ff and shift lever in P r N. Standard: Engine Cnditin Idling Techstream Display Less than 80 kpa (600 mmhg) Result: Result Prceed t NG A OK B B CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED A 9. CHECK INTAKE SYSTEM (a) Check the intake system fr vacuum leaks. OK:
N leaks in intake system. NG REPAIR OR REPLACE INTAKE SYSTEM OK 10. REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR (a) Replace the manifld abslute pressure sensr. NEXT 11. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED (a) Cnnect the Techstream t the DLC3. (b) Turn the pwer switch n (IG). (c) Turn the Techstream n. (d) Clear the DTC. (e) Turn the pwer switch ff and wait fr 30 secnds. (f) Turn the pwer switch n (IG) and turn the Techstream n. (g) Put the engine in inspectin mde. (h) Start the engine and warm it up until the engine clant temperature reaches 70 C (158 F) r mre. The A/C switch and all accessry switches shuld be ff and shift lever in P r N. (i) Drive the vehicle at 25 t 37 mph (40 t 60 km/h) with the shift lever in B. CAUTION: Strictly bserve speed limits and traffic laws when perfrming the cnfirmatin drive pattern. (j) Perfrm fuel cut peratin fr 5 secnds r mre with the acceleratr pedal fully released. If the deceleratin was nt cmpleted, perfrm the Cnfirmatin Driving Pattern again. (k) Enter the fllwing menus: Pwertrain / Engine and ECT / Truble Cdes / Pending. (l) Read Pending DTC.
(m) If the pending DTC is utput, the system is malfunctining. If a pending DTC is nt utput, perfrm the fllwing prcedure. (n) Enter the fllwing menus: Pwertrain / Engine and ECT / Utility / All Readiness. () Input the DTC: P0401. (p) Check the DTC judgment result. Techstream Display NORMAL ABNORMAL DTC judgment cmpleted System nrmal DTC judgment cmpleted System abnrmal Descriptin INCOMPLETE UNKNOWN DTC judgment nt cmpleted Perfrm driving pattern after cnfirming DTC enabling cnditins Unable t perfrm DTC judgment Number f DTCs which d nt fulfill DTC precnditins has reached ECU's memry limit If the pending DTC is nt utput and the DTC judgment result is INCOMPLETE r UNKNOWN, drive the vehicle again at 25 t 37 mph (40 t 60 km/h) with the shift lever in B, perfrm fuel cut peratin fr 5 secnds r mre with the acceleratr pedal fully released, and check the DTC judgment result. NEXT END
DTC P0403 Exhaust Gas Recirculatin Cntrl Circuit DESCRIPTION Refer t DTC P0401. DTC N. DTC Detectin Cnditin Truble Area Open r shrt in EGR valve circuit P0403 (1 trip detectin lgic) Open r shrt in EGR circuit EGR valve assembly ECM DTC P0403 is set when the pwer switch is n (IG). MONITOR DESCRIPTION This DTC is designed t detect an pen r shrt in the EGR valve assembly circuit. Example: If the EGR1, EGR2, EGR3 r EGR4 terminal utput vltage is excessively lw, but the step mtr is still perating, the ECM determines that there is a shrt in the EGR valve assembly circuit, and sets the DTC. If the EGR1, EGR2, EGR3 r EGR4 terminal utput vltage is excessively lw, and the step mtr is nt perating, the ECM determines that there is an pen in the EGR valve assembly circuit, and sets the DTC. MONITOR STRATEGY Related DTCs P0403: EGR valve circuit range check Required sensrs / cmpnents (Main) EGR valve assembly Required sensrs / cmpnents (Related) - Frequency f peratin Cntinuus Duratin 0.5 secnds MIL peratin Immediately Sequence f peratin Nne TYPICAL ENABLING CONDITIONS Mnitr runs whenever fllwing DTCs are nt present Engine Battery vltage Nne Running 10.5 V r mre
Time after pwer switch ff t n (IG) Mre than 0.5 secnds TYPICAL MALFUNCTION THRESHOLDS One f the fllwing cnditins is met: Cnditins A, B, C r D A. All f the cnditins are met: Cnditins 1 and 2 1. EGR1 utput terminal vltage Lw vltage 2. Either f the fllwing cnditins is met: Cnditin (a) r (b) (a) Step mtr Driving (b) EGR1 Nt perating B. All f the fllwing cnditins are met: Cnditins 3 and 4 3. EGR2 utput terminal vltage Lw vltage 4. Either f the fllwing cnditins is met: Cnditin (c) r (d) (c) Step mtr Driving (d) EGR2 Nt perating C. All f the fllwing cnditins are met: Cnditins 5 and 6 5. EGR3 utput terminal vltage Lw vltage 6. Either f the fllwing cnditins is met: Cnditin (e) r (f) (e) Step mtr Driving (f) EGR3 Nt perating D. All f the fllwing cnditins are met: Cnditins 7 and 8 7. EGR4 utput terminal vltage Lw vltage 8. Either f the fllwing cnditins is met: Cnditin (g) r (h) (g) Step mtr Driving (h) EGR4 Nt perating CONFIRMATION DRIVING PATTERN
1. Cnnect the Techstream t the DLC3. 2. Turn the pwer switch n (IG) and turn the Techstream n. 3. Clear the DTCs (even if n DTCs are stred, perfrm the clear DTC prcedure). 4. Turn the pwer switch ff and wait fr 30 secnds. 5. Turn the pwer switch n (IG) and turn the Techstream n [A]. 6. Put the engine in inspectin mde. 7. Start the engine and warm it up [B]. 8. Drive the vehicle at 12 mph (20 km/h) r mre fr 10 minutes [C]. 9. Enter the fllwing menus: Pwertrain / Engine and ECT / Truble Cdes. 10. Read the DTCs [D]. 11. If the DTC P0403 is utput, the system is malfunctin. If a DTC is nt utput, perfrm the fllwing prcedure. 12. Enter the fllwing menus: Pwertrain / Engine and ECT / Utility / All Readiness. 13. Input the DTC: P0403. 14. Check the DTC judgment result. Techstream Display NORMAL ABNORMAL DTC judgment cmpleted System nrmal DTC judgment cmpleted System abnrmal Descriptin INCOMPLETE DTC judgment nt cmpleted
Techstream Display UNKNOWN Descriptin Perfrm driving pattern after cnfirming DTC enabling cnditins Unable t perfrm DTC judgment Number f DTCs which d nt fulfill DTC precnditins has reached ECU's memry limit CAUTION: When perfrming the cnfirmatin driving pattern, bey all speed limits and traffic laws. If the judgment result shws ABNORMAL, the system has a malfunctin. If the judgment result shws NORMAL, the system has a nrmal. 15. If the test result is INCOMPLETE r UNKNOWN, drive the vehicle at 12 mph (20 km/h) r mre fr 10 minutes, and check the DTC judgment result. If the judgment result shws ABNORMAL, the system has a malfunctin. If the judgment result shws NORMAL, the system has a nrmal. 16. If the test result is INCOMPLETE r UNKNOWN and n DTC is utput, perfrm a universal trip and check fr permanent DTCs. If a permanent DTC is utput, the system is malfunctining. If n permanent DTC is utput, the system is nrmal. WIRING DIAGRAM
INSPECTION PROCEDURE NOTICE: Inspect the fuses fr circuits related t this system befre perfrming the fllwing inspectin prcedure. Read freeze frame data using the Techstream. The ECM recrds vehicle and driving cnditin infrmatin as freeze frame data the mment a DTC is stred. When trubleshting, freeze frame data can help determine if the vehicle was mving r statinary, if the engine was warmed up r nt, if the air fuel rati was lean r rich, and ther data frm the time the malfunctin ccurred. PROCEDURE 1. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE EGR STEP POSITION) (a) Cnnect the Techstream t the DLC3. (b) Turn the pwer switch n (IG).
(c) Turn the Techstream n. (d) Put the engine in inspectin mde. (e) Start the engine and warm it up until the engine clant temperature reaches 75 C (167 F) r mre. The A/C switch and all accessry switches shuld be ff. (f) Enter the fllwing menus: Pwertrain / Engine and ECT / Active Test / Cntrl the EGR Step Psitin. (g) Cnfirm the Thrttle Idle Psitin is ON and check the engine idling cnditin and MAP values in the Data List while perfrming the Active Test. D nt leave the EGR valve pen fr 10 secnds r mre during the Active Test. Be sure t return the EGR valve t step 0 when the Active Test is cmpleted. D nt pen the EGR valve 30 steps r mre during the Active Test. OK: MAP and idling cnditin change in respnse t EGR step psitin when Thrttle Idle Psitin is ON in Data List. Standard: - Idling cnditin MAP (Data List) EGR Step Psitin (Active Test) 0 Steps 0 t 30 Steps Steady idling MAP value is 20 t 40 kpa (150 t 300 mmhg) (EGR valve is fully clsed) Idling changes frm steady t rugh idling MAP value is at least +10 kpa (75 mmhg) higher than when EGR valve is fully clsed During Active Test, if the idling cnditin des nt change in respnse t EGR step psitin, then there is prbably a malfunctin in the EGR valve. Result: Result Within standard range Outside f standard range B INSPECT EGR VALVE ASSEMBLY A B Prceed t
A CHECK FOR INTERMITTENT PROBLEMS 2. INSPECT EGR VALVE ASSEMBLY (a) Discnnect the EGR valve assembly cnnectr. (b) Measure the resistance accrding t the value(s) in the table belw. Standard Resistance: Tester Cnnectin Cnditin Specified Cnditin 2 (+B1) - 3 (EGR2) 2 (+B1) - 1 (EGR4) 5 (+B2) - 4 (EGR1) 5 (+B2) - 6 (EGR3) 20 C (68 F) 20 t 22 Ω Text in Illustratin *1 Cmpnent withut harness cnnected (EGR Valve Assembly) (c) Recnnect the EGR valve assembly cnnectr. NG REPLACE EGR VALVE ASSEMBLY OK 3. INSPECT EGR VALVE ASSEMBLY (+B1 OR +B2 VOLTAGE) (a) Discnnect the EGR valve assembly cnnectr. (b) Turn the pwer switch n (IG). (c) Measure the vltage accrding t the value(s) in the table belw. Standard Vltage: Tester Cnnectin Switch Cnditin Specified Cnditin D10-2 (+B1) - Bdy grund Pwer switch n (IG) 11 t 14 V D10-5 (+B2) - Bdy grund Text in Illustratin *1 Frnt view f wire harness cnnectr (t EGR Valve Assembly)
(d) Recnnect the EGR valve assembly cnnectr. NG OK REPAIR OR REPLACE HARNESS OR CONNECTOR (EGR VALVE ASSEMBLY - EFI MAIN RELAY) 4. CHECK HARNESS AND CONNECTOR (ECM - EGR VALVE ASSEMBLY) (a) Discnnect the EGR valve assembly cnnectr. (b) Discnnect the ECM cnnectr. (c) Measure the resistance accrding t the value(s) in the table belw. Standard Resistance (Check fr Open): Tester Cnnectin Cnditin Specified Cnditin D28-45 (EGR1) - D10-4 (EGR1) D28-44 (EGR2) - D10-3 (EGR2) D28-43 (EGR3) - D10-6 (EGR3) D28-42 (EGR4) - D10-1 (EGR4) Standard Resistance (Check fr Shrt): Always Belw 1 Ω Tester Cnnectin Cnditin Specified Cnditin D28-45 (EGR1) r D10-4 (EGR1) - Bdy grund D28-44 (EGR2) r D10-3 (EGR2) - Bdy grund D28-43 (EGR3) r D10-6 (EGR3) - Bdy grund D28-42 (EGR4) r D10-1 (EGR4) - Bdy grund Text in Illustratin Always 10 kω r higher
*1 Frnt view f wire harness cnnectr (t EGR Valve Assembly) *2 Frnt view f wire harness cnnectr (t ECM) (d) Recnnect the ECM cnnectr. (e) Recnnect the EGR valve assembly cnnectr. NG REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - EGR VALVE ASSEMBLY) OK 5. CHECK DTC OUTPUT RECORDS (DTC P0403) (a) Cnnect the Techstream t the DLC3. (b) Turn the pwer switch n (IG) and turn the Techstream n. (c) Clear the DTCs. (d) Put the engine in inspectin mde. (e) Start the engine warm it up. (f) Drive the vehicle in accrdance with the driving pattern described in the Cnfirmatin Driving Pattern. (g) Enter the fllwing menus: Pwertrain / Engine and ECT / Truble Cdes. (h) Read the DTCs. Result: B REPLACE ECM A END Result DTC is nt utput DTC P0403 is utput Prceed t A B