STOP AND START STOP AND START SYSTEM P323A19 Backup Boost Converter "A" Circuit Current Above Threshold
DESCRIPTION
A backup boost converter is built into the engine stop and start ECU.
The backup boost converter helps maintain battery voltage to prevent various functions from failing if power source voltage supplied from the backup boost converter drops due to the high electrical load when the engine is restarted by stop and start control.
The backup boost converter helps maintain the power source voltage if the battery voltage drops due to the high electrical load when the engine is restarted by stop and start control.
- HINT:
-
A relay function and fuse function are provided in the backup boost converter.
-
If there is a malfunction in any of the electrical system circuits connected to the backup boost converter, the fuse and relay functions shut off the malfunctioning circuit to protect other circuits (remains shut off until next trip).
-
When the electrical system circuit is shut off, power to the circuit is cut off, causing any systems connected to the circuit to be disabled.
-
The fuse function is reset* when the ignition switch is turned off. If the malfunction still exists in the electrical system circuit that has been shut off by the relay function, it will be shut off again by the relay and fuse functions the next time the ignition switch is turned to ON.
-
*: A semiconductor fuse self resets according to electric signal.
- The backup boost converter supplies power to:·
Front radar sensor system
·Electronically controlled brake system
·Pre-collision system
·Audio and visual system
·Navigation system
·Digital rear-view mirror system
·Wireless door lock control system
·Lighting system (INT)
·CAN communication system
·Meter / gauge system
·Panoramic view monitor system
·Dynamic radar cruise cintrol system
·Front camera system
·Tire pressure warning system
·Blind spot monitor system
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Warning Indicate | Memory | Note |
|---|---|---|---|---|---|---|
| P323A19 | Backup Boost Converter "A" Circuit Current Above Threshold | The following condition continues for 1 second or more (1 trip detection logic):
·
Overcurrent is detected at the B41, B42, B43 and IG41 terminals in the engine stop and start ECU |
·
Wire harness or connector ·
Door control receiver*1 ·
Inner rear view mirror assembly*2 ·
No. 1 integration relay (DOME CUT NO.2 relay) ·
Radio and display receiver assembly ·
Navigation ECU*3 ·
Network gateway ECU ·
Instrument panel junction block assembly (main body ECU (multiplex network body ECU)) ·
Millimeter Wave Radar Sensor Assembly*4 ·
Parking Assist ECU*5*9 ·
Inner rear view mirror assembly*6 ·
Blind spot monitor sensor LH*7 ·
Blind spot monitor sensor RH*7 ·
Tire pressure warning ECU and receiver*8 ·
NO. 1 interior illumination light assembly (slide door illumination) ·
NO. 2 interior illumination light assembly (slide door illumination) ·
NO. 1 interior illumination light assembly (quarter trim illumination) ·
NO. 2 interior illumination light assembly (quarter trim illumination) ·
Spot light assembly (for front LH) ·
Spot light assembly (for rear LH) ·
Spot light assembly (for front RH) ·
spot light assembly (for rear RH) ·
Engine stop and start ECU |
Blinks | DTC stored | SAE Code: P323A |
*1: w/ Wireless Door Lock Control System
*2: w/ Digital Rear-View Mirror System
*3: w/ Navigation System
*4: w/ Front Radar Sensor System
*5: w/ Panoramic View Monitor System
*6: w/ Rear View Mirror System
*7: w/ Blind Spot Monitor System
*8: w/ Tire Pressure Warning System
*9: Production date from 2019/06 to 2023/10
CONFIRMATION DRIVING PATTERN
CONFIRMATION AFTER TROUBLESHOOTING
- HINT:
- ·
If the cable is disconnected from the battery terminal, stop and start control is prohibited until refresh charge is completed.
In this case, let the vehicle idle to complete the refresh charge. The refresh charge is complete when the Data List item "Status of Battery Charge Control" changes from "Refresh Charge Mode". (Usually, idling the engine for 5 to 60 minutes with the battery fluid temperature at 11°C (51°F) or higher, the refresh charge will be completed.)
·If the GTS is not available and the Data List item "Status of Battery Charge Control" cannot be checked, charge the battery by idling the engine for approximately 5 to 60 minutes or driving the vehicle, and then drive the vehicle and check that stop and start control operates.
If the engine is started with the hood open, the system determines that a jump start has occurred. Therefore, make sure that the hood is closed before starting the engine and driving the vehicle.
·After the refresh charge completes, turn the ignition switch off, wait for at least 30 seconds, and then start the engine again. If the vehicle enters refresh charge mode again while the engine is idling, the initial refresh charge did not properly complete, so wait for the refresh charge to complete.
·Allow the engine to idle for 3 minutes after it is warmed up and check that the engine idle speed is within 50 rpm of the target idle speed.
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs.
- Powertrain > Stop and Start > Clear DTCs
- 50002 392
Start the engine and warm it up.
Drive the vehicle at 7 km/h (4 mph) or more.
- CAUTION:
-
When performing Confirmation Driving Pattern, obey all speed limits and traffic laws.
for Automatic Transmission:
Depress the brake pedal and stop the vehicle.
for Manual Transmission:
Stop the vehicle, move the shift lever to neutral and release the clutch pedal.
Keep the engine stopped by stop and start control for 1 second or more. (for Automatic Transmission: Keep the shift lever in D.)
for Automatic Transmission:
Release the brake pedal with the shift lever in D to start the engine.
for Manual Transmission:
Depress the clutch pedal and start the engine.
- HINT:
-
If the engine cranks slowly when the engine is restarted, it can be determined that the battery voltage is low.
Check that DTCs are not output.
- Powertrain > Stop and Start > Trouble Codes
- 50001 392
STOP AND START SYSTEM OPERATION CHECK
- HINT:
- ·
If the cable is disconnected from the battery terminal, stop and start control is prohibited until refresh charge is completed.
In this case, let the vehicle idle to complete the refresh charge. The refresh charge is complete when the Data List item "Status of Battery Charge Control" changes from "Refresh Charge Mode". (Usually, idling the engine for 5 to 60 minutes with the battery fluid temperature at 11°C (51°F) or higher, the refresh charge will be completed.)
·If the GTS is not available and the Data List item "Status of Battery Charge Control" cannot be checked, charge the battery by idling the engine for approximately 5 to 60 minutes or driving the vehicle, and then drive the vehicle and check that stop and start control operates.
If the engine is started with the hood open, the system determines that a jump start has occurred. Therefore, make sure that the hood is closed before starting the engine and driving the vehicle.
·After the refresh charge completes, turn the ignition switch off, wait for at least 30 seconds, and then start the engine again. If the vehicle enters refresh charge mode again while the engine is idling, the initial refresh charge did not properly complete, so wait for the refresh charge to complete.
Start the engine and warm it up.
Turn the air conditioning system off.
Drive the vehicle at 7 km/h (4 mph) or more.
- CAUTION:
-
When performing Confirmation Driving Pattern, obey all speed limits and traffic laws.
for Automatic Transmission:
Depress the brake pedal and stop the vehicle.
for Manual Transmission:
Stop the vehicle, move the shift lever to neutral and release the clutch pedal.
Allow the engine to stop by stop and start control. (for Automatic Transmission: Keep the shift lever in D.)
for Automatic Transmission:
Release the brake pedal with the shift lever in D to start the engine.
for Manual Transmission:
Depress the clutch pedal and start the engine.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
- NOTICE:
- ·
Before replacing the engine stop and start ECU, read the number of starter operations and write it into a new engine stop and start ECU.
·After replacing the engine stop and start ECU or air conditioning amplifier assembly, reset and perform learning of the air conditioning information in the engine stop and start ECU.
·After replacing the engine stop and start ECU or airbag sensor assembly, clear and calibrate the deceleration sensor zero point in the engine stop and start ECU.
·for Automatic Transmission:
When the engine stop and start ECU or electromagnetic oil pump is replaced, check the electromagnetic oil pump.
·Inspect the fuses for circuits related to this system before performing the following procedure.
- HINT:
- ·
If electrical load from additional devices installed to the vehicle (aftermarket audio system, etc.) is applied to the B41, B42, B43 or IG41 terminal in the engine stop and start ECU, the fuse function of the backup boost converter may operate.
If the fuse function of the backup boost converter operates, any systems connected to the B41, B42, B43 or IG41 terminal in the engine stop and start ECU will not operate.
·If DTCs P279612 (Electromagnetic Oil Pump Circuit Short to Battery), P279614 (Electromagnetic Oil Pump Circuit Open), P279796 (Electromagnetic Oil Pump Component Internal Failure) and P323A19 (Backup Boost Converter "A" Circuit Current Above Threshold) are output simultaneously, troubleshoot for DTC P279612, P279614 or P279796 first, as a malfunction which causes DTC P279612, P279614 or P279796 to be stored may also cause DTC P323A19 to be stored.
·DTCs for the stop and start system are not cleared even if the malfunction has been repaired. After repairing the malfunction, be sure to clear the DTCs.
·Using the GTS, read the freeze frame data before troubleshooting. System condition information is recorded as freeze frame data the moment a DTC is stored. This information can be useful when troubleshooting.
PROCEDURE
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Stop and Start / Trouble Codes.
Read the DTCs.
- Powertrain > Stop and Start > Trouble Codes
- 50001 392
- Result:
Result Proceed to DTC P323A19 is output A DTC P279612, P279614 or P279796 and P323A19 are output B
- HINT:
-
If DTCs P323A19 and P279612, P279614 or P279796 are output simultaneously, troubleshoot for DTC P279612, P279614 or P279796 first.
A
B
Disconnect the engine stop and start ECU connector.
Remove the BBC-1 fuse and BBC-2 fuse from the No. 1 engine room relay block and No. 1 junction block assembly.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition N31-1 (BIN2) - BBC-2 fuse terminal 2 Always Below 1 Ω N31-3 (BIN1) - BBC-1 fuse terminal 2 Always Below 1 Ω N31-1 (BIN2) or BBC-2 fuse terminal 2 - Body ground and other terminals Always 10 kΩ or higher N31-3 (BIN1) or BBC-1 fuse terminal 2 - Body ground and other terminals Always 10 kΩ or higher
- Result:
Proceed to OK NG
OK
NG
Disconnect the engine stop and start ECU connector.
Disconnect the door control receiver connector.*1
Disconnect the inner rear view mirror assembly connector.*2
Disconnect the No. 1 integration relay (DOME CUT NO.2 relay) connector.
Disconnect the Parking Assist ECU.*3*9
Disconnect the tire pressure warning ECU and receiver connector.*4
Disconnect the NO. 1 interior illumination light assembly (slide door illumination) connector.
Disconnect the NO. 2 interior illumination light assembly (slide door illumination) connector.
Disconnect the NO. 1 interior illumination light assembly (quarter trim illumination) connector.
Disconnect the NO. 2 interior illumination light assembly (quarter trim illumination) connector.
Disconnect the spot light assembly (for front LH) connector.
Disconnect the spot light assembly (for rear LH) connector.
Disconnect the spot light assembly (for front RH) connector.
Disconnect the spot light assembly (for rear RH) connector.
Disconnect the radio and display receiver assembly connector.
Disconnect the navigation ECU connector.*5
Disconnect the network gateway ECU connector.
Disconnect the instrument panel junction block assembly (main body ECU (multiplex network body ECU)) connector.
Disconnect the millimeter wave radar sensor assembly connector.*6
Disconnect the inner rear view mirror assembly connector.*7
Disconnect the blind spot monitor sensor LH connector.*8
Disconnect the blind spot monitor sensor RH connector.*8
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition N33-2 (B41) - b2-5 (+B)*1 Always Below 1 Ω N33-2 (B41) - a5-6 (+B)*2 Always Below 1 Ω N33-2 (B41) - 1C-7 Always Below 1 Ω N33-2 (B41) - 1C-8 Always Below 1 Ω N33-2 (B41) - N151-1(+B)*3*9 Always Below 1 Ω N33-2 (B41) - N151-19(+B2)*3*9 Always Below 1 Ω N33-2 (B41) - Z30-7(+B)*4 Always Below 1 Ω N33-2 (B41) - U10-1(ILL+) Always Below 1 Ω N33-2 (B41) - U12-1(ILL+) Always Below 1 Ω N33-2 (B41) - W31-1(ILL+) Always Below 1 Ω N33-2 (B41) - V29-1(ILL+) Always Below 1 Ω N33-2 (B41) - a26-5(+) Always Below 1 Ω N33-2 (B41) - a25-5(+) Always Below 1 Ω N33-2 (B41) - a35-5(+) Always Below 1 Ω N33-2 (B41) - a34-5(+) Always Below 1 Ω N33-12 (B42) - O5-4 (+B1) Always Below 1 Ω N33-11 (B43) - O9-10 (+B)*5 Always Below 1 Ω N33-3 (IG41) - N21-11 (IG1) Always Below 1 Ω N33-3 (IG41) - 3A-15 Always Below 1 Ω N33-3 (IG41) - A3-8 (IGB)*6 Always Below 1 Ω N33-3 (IG41) - N151-21(IG)*3*9 Always Below 1 Ω N33-3 (IG41) - a7-6(IG)*7 Always Below 1 Ω N33-3 (IG41) - e2-5(BLB)*8 Always Below 1 Ω N33-3 (IG41) - e3-5(BRB)*8 Always Below 1 Ω N33-3 (IG41) - Z30-1(IG)*4 Always Below 1 Ω N33-2 (B41) - Body ground and other terminals Always 10 kΩ or higher N33-12 (B42) - Body ground and other terminals Always 10 kΩ or higher N33-11 (B43) - Body ground and other terminals Always 10 kΩ or higher N33-3 (IG41) - Body ground and other terminals Always 10 kΩ or higher
*1: w/ Wireless Door Lock Control System
*2: w/ Digital Rear-View Mirror System
*3: w/ Panoramic view monitor system
*4: w/ Tire Pressure Warning System
*5: w/ Navigation System
*6: w/ Front Radar Sensor System
*7: w/ Rear View Mirror System
*8: w/ Blind Spot Monitor System
*9: Production date from 2019/06 to 2023/10
- Result:
Proceed to OK NG
OK
NG
| *a | Component without harness connected
(Engine Stop and Start ECU) |
- | - |
Disconnect the engine stop and start ECU connectors.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition N33-2 (B41) - N32-6 (DGND) Always 10 kΩ or higher N33-3 (IG41) - N32-6 (DGND) Always 10 kΩ or higher N33-11 (B43) - N32-6 (DGND) Always 10 kΩ or higher N33-12 (B42) - N32-6 (DGND) Always 10 kΩ or higher
- Result:
Proceed to OK NG
OK
NG
Check that additional devices installed to the vehicle (aftermarket audio system, etc.) are not connected to the B41, B42, B43 or IG41 terminal circuit of the engine stop and start ECU.
- Result:
Result Proceed to Load from an additional device installed to the vehicle (aftermarket audio system, etc.) is not applied. A Load from an additional device installed to the vehicle (aftermarket audio system, etc.) is applied. B
A
B