Check for damaged harness and terminals including rubber seals :
-. contact resistance, oxidation, corrosion, bent or broken terminals
-. harness connector connection, loose wires etc.
Check for poor connection between ECM and component :
-. backed out terminal, improper mating, broken locks and poor terminal to wire connection
ARE THE WIRES O.K ? & ARE THE CONNECTIONS O.K ?
YES
Go to "Signal Circuit Inspection" procedure.
NO
Repair as necessary and go to " Verification of Vehicle Repair " procedure
DTCs listed below are stored in the scan tool
P0401/P0402/P0405/P0406
Check items with the scan tool and the multimeter
① Wiring harness inspection
② Check the fuse
③ Check the relay resistance
④ Waveform from EGR sol.valve
Specification
Resitance : below 1 Ω for open in the wire
Resitance : infinite for short to ground in the wire
Voltage : below 0.5V for short to power in the wire
Battery voltage : Approx. 12V
Resitance : 14 - 17 Ω at 20℃(68℉)
Refer to the component and full circuit for connector configrations details
Turn the ignition switch ON and measure the voltage at the EGR sol. valve terminal 1 and the EGR sol. valve terminal 2 individually.
ARE THERE THE BATTERY VOLTAGE ?
YES
Go to step 3
NO
Repair open or short in the wire between the EGR sol. valve terminal 2 and the ECM No.3 fuse (10A)
Replace the fuse if the fuse is broken
Replace the EGR sol. valve. For more detailed information, Go to "Component Inspection" procedure
Go to step 3
Connect the CH A probe of scan tool to the EGR sol. valve terminal 1 after turning the ignition switch OFF and then start the engine.
Check the EGR sol. valve signal waveform when depressing the accel pedal fully one time
IS THERE THE EGR SOL.VALVE SIGNAL WAVEFORM PRORERLY DISPLAYED ?
YES
Go to step 9
NO
Go to step 6
WAVEFOAM ANALYSIS
This test should be inspected after depressing the HOLD mode at the operating range of EGR valve. The time T becomes shorter when the EGR valve is opened increasingly. If the rectangular waveform pattern is distorted and omitted, replace the EGR sol. valve.
Connect the CH A probe of scan tool to the ECM terminal 16/C230-1 after turning the ignition switch OFF and then start the engine
Check the EGR sol. valve signal waveform when depressing the accel pedal fully one time.
IS THERE THE EGR SOL.VALVE WAVEFORM PRORERLY DISPLAYED ?
YES
Go to step 9
NO
Replace a known - good ECM and recheck. If the signal waveform is displayed properly, replace the ECM
Go to step 9
Check the signal waveform at the MAFS terminal 1 when depressing the accelerator pedal fully one time.
IS THERE THE SIGNAL WAVEFORM PROPERLY DISPLAYED ?
YES
Go to "Verification of Vehicle Repair" procedure
NO
Replace the MAFS
Inspect whether or not the throttle actuator stick or normal operation and EGR valve stick or normal operation. For more detailed information, Go to "DTC P1190 Component Inspection" procedure. For more detailed information, Go to "Component Inspection" procedure
WAVEFORM ANALYSIS
This test should be inspected after depressing the HOLD mode from run during the idling, acceleration and deceleration. As accel pedal is pressed down fully, the intensity of the waveform increases individually. The waveform pattern become increasing upward rapidly when the engine speed increases. If the waveform pattern becomes distorted during the acceleration or deceleration, replace the MAFS.
Connect the scan tool to the data link connector(DLC) and start the engine
Fix the mass air flow, the engine rpm, the barometric pressure sensor, the injector current data and check.
Perform test drive and check the fixed current data in the overrun range after releasing the accel pedal.
① This test should be inspected below 250 mg/st as against the normal value from MAFS under the condition of engine from 700 to 1920 rpm (overrun range after releasing the accel pedal) and the fuel injection quantity below 12 mcc.
② Keep the above test condition of P0401 for more than 200 seconds.
③ Intact detection debouncing condition for more than 656 seconds.
Check the current data during the test drive.
IS THE CURRENT DATA DISPLAYED PROPERLY ?
YES
Go to "Verification of Vehicle Repair" procedure
NO
Replace the MAFS
Inspect whether or not the throttle actuator stick or normal operation and EGR valve stick or normal operation. For more detailed information, Go to "DTC P1190 Component Inspection" procedure. For more detailed information, Go to "DTC P0102 ~ 0104 Component Inspection" procedure.
Turn the ignition switch ON and measure the voltage at the EGR sol. valve terminal 1 and the EGR sol. Valve terminal 2 individually.
ARE THERE THE BATTERY VOLTAGE ?
YES
Go to step 3
NO
Repair open or short in the wire between the EGR sol. valve terminal 2 and the ECM No.3 fuse (10A)
Replace the fuse if the fuse is broken
Replace the EGR sol. valve. For more detailed information, Go to "Component Inspection" procedure
Go to step 3
Connect the CH A probe of scan tool to the EGR sol. valve terminal 1 after turning the ignition switch OFF and then start the engine.
Check the EGR sol. valve signal waveform when depressing the accel pedal fully one time.
IS THERE THE EGR SOL.VALVE SIGNAL WAVEFORM PRORERLY DISPLAYED ?
YES
Go to step 9
NO
Go to step 6
WAVEFOAM ANALYSIS
This test should be inspected after depressing the HOLD mode at the operating range of EGR valve. The time T becomes shorter when the EGR valve is opened increasingly. If the rectangular waveform pattern is distorted and omitted, replace the EGR sol. valve.
Connect the CH A probe of scan tool to the ECM terminal 16/C230-1 after turning the ignition switch OFF and then start the engine
Check the EGR sol. valve signal waveform when depressing the accel pedal fully one time.
IS THERE THE EGR SOL.VALVE WAVEFORM PRORERLY DISPLAYED ?
YES
Go to step 9
NO
Replace a known - good ECM and recheck. If the signal waveform is displayed properly, replace the ECM
Go to step 9
Check the signal waveform at the MAFS terminal 1 when depressing the accelerator pedal fully one time.
IS THERE THE SIGNAL WAVEFORM PROPERLY DISPLAYED ?
YES
Go to "Verification of Vehicle Repair" procedure
NO
Replace the MAFS
Inspect whether or not the throttle actuator stick or normal operation and EGR valve stick or normal operation. For more detailed information, Go to "DTC P1190 Component Inspection" procedure. For more detailed information, Go to "Component Inspection" procedure
WAVEFORM ANALYSIS
This test should be inspected after depressing the HOLD mode from run during the idling, acceleration and deceleration. As accel pedal is pressed down fully, the intensity of the waveform increases individually. The waveform pattern become increasing upward rapidly when the engine speed increases. If the waveform pattern becomes distorted during the acceleration or deceleration, replace the MAFS.
Connect the scan tool to the data link connector(DLC) and start the engine
Fix the mass air flow, the engine rpm, the barometric pressure sensor, the injector current data and check.
Perform test drive and check the fixed current data in the overrun range after releasing the accel pedal.
① This test should be inspected above 340 mg/st as against the normal value from MAFS under the condition of engine from 700 to 1920 rpm (overrun range after releasing the accel pedal) and the fuel injection quantity below 12 mcc.
② Keep the above test condition of P0402 for more than 7 seconds.
③ Intact detection debouncing condition for more than 656 seconds.
Check the current data during the test drive.
IS THE CURRENT DATA DISPLAYED PROPERLY ?
YES
Go to "Verification of Vehicle Repair" procedure
NO
Replace the MAFS
Inspect whether or not the throttle actuator stick or normal operation and EGR valve stick or normal operation. For more detailed information, Go to "DTC P1190 Component Inspection" procedure. For more detailed information, Go to "DTC P0102 ~ 0104 Component Inspection" procedure
Erase the DTC
Start the engine
IS THERE DTC P0405 INDICATED ?
YES
Go to step 4
NO
Intermittent failure, system is O.K at this time.
Go to step 4
Stop the engine and turn the ignition switch ON.
Measure the voltage at the EGR sol.valve terminal 1 and the EGR sol.valve terminal 2 individually.
ARE THERE THE BATTERY VOLTAGE ?
YES
Go to step 7
NO
Repair open or short in the wire between the EGR sol. valve terminal 2 and the ECM No.3 fuse (10A)
Replace the fuse if the fuse is broken
Replace the EGR sol. valve if the EGR sol. valve is defective after checking the continuity between the relay terminal 1 and terminal 2. For more detailed information, Go to "Component Inspection" procedure
Go to step 7
Connect the CH A probe of scan tool to the EGR sol. valve terminal 1 after turning the ignition switch OFF and then start the engine
Check the EGR sol. valve signal waveform when depressing the accel pedal fully one time.
IS THERE THE EGR SOL.VALVE SIGNAL WAVEFORM PRORERLY DISPLAYED ?
YES
Go to "Verification of Vehicle Repair" procedure
NO
Go to step 10
WAVEFOAM ANALYSIS
This test should be inspected after depressing the HOLD mode at the operating range of EGR valve. The time T becomes shorter when the EGR valve is opened increasingly. If the rectangular waveform pattern is distorted and omitted, replace the EGR sol. valve.
Connect the CH A probe of scan tool to the ECM terminal 16/C230-1 after turning the ignition switch OFF and then start the engine
Check the EGR sol. valve signal waveform when depressing the accel pedal fully one time.
IS THERE THE EGR SOL.VALVE WAVEFORM PRORERLY DISPLAYED ?
YES
Go to "Verification of Vehicle Repair" procedure
NO
Replace a known - good ECM and recheck. If the waveform is displayed properly, replace the ECM
Erase the DTC
Start the engine
IS THERE DTC P0406 INDICATED ?
YES
Go to step 4
NO
Intermittent failure, system is O.K at this time.
Go to step 4
Stop the engine and turn the ignition switch ON.
Measure the voltage at the EGR sol.valve terminal 1 and the EGR sol.valve terminal 2 individually.
ARE THERE THE BATTERY VOLTAGE ?
YES
Go to step 7
NO
Repair short in the wire between the EGR sol. valve terminal 2 and ECM No.3 fuse (10A)
Replace the fuse if the fuse is broken
Replace the EGR sol. valve if the EGR sol. valve is defective after checking the continuity between the relay terminal 1 and terminal 2. or more detailed information, Go to "Component Inspection" procedure
Go to step 7
Connect the CH A probe of scan tool to the EGR sol. valve terminal 1 after turning the ignition switch OFF and then start the engine
Check the EGR sol. valve signal waveform when depressing the accel pedal fully one time.
IS THERE THE EGR SOL.VALVE SIGNAL WAVEFORM PRORERLY DISPLAYED ?
YES
Go to "Verification of Vehicle Repair" procedure
NO
Go to step 10
WAVEFORM ANALYSIS
This test should be inspected after depressing the HOLD mode at the operating range of EGR valve. The time T becomes shorter when the EGR valve is opened increasingly. If the rectangular waveform pattern is distorted and omitted, replace the EGR sol. valve.
Connect the CH A probe of scan tool to the ECM terminal 16/C230-1 after turning the ignition switch OFF and then start the engine
Check the EGR sol. valve signal waveform when depressing the accel pedal fully one time.
IS THERE THE EGR SOL.VALVE WAVEFORM PRORERLY DISPLAYED ?
YES
Go to "Verification of Vehicle Repair" procedure
NO
Replace a known - good ECM and recheck. If the signal waveform is displayed properly, replace the ECM