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 auxiliary 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 auxiliary 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:·
Meter / gauge system
·Power steering system
·Audio and visual system
·Tire pressure warning system
·Air conditioning system
·Navigation system
·Electronically controlled brake system
·Toyota parking assist-sensor system
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Warning Indicate | 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 and IG41 terminals in the engine stop and start ECU |
·
Wire harness or connector ·
Engine stop and start ECU ·
Tire pressure warning ECU and receiver ·
Radio and display receiver assembly ·
Combination meter assembly ·
Power steering ECU assembly ·
Skid control ECU (brake actuator assembly) ·
Steering sensor ·
Clearance warning ECU assembly*1 ·
Air Conditioning Control Assembly*2 |
Blinks | SAE Code: P323A |
*1: w/ Clearance Sonar System
*2: for Electrical Control Type
CONFIRMATION DRIVING PATTERN
CONFIRMATION AFTER TROUBLESHOOTING
- HINT:
- ·
If the cable is disconnected from the auxiliary 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 auxiliary battery fluid temperature at 11°C (52°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 auxiliary 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.
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.
Depress the brake pedal and stop the vehicle.
Keep the engine stopped by stop and start control for 1 second or more. (Keep the shift lever in D.)
Release the brake pedal with the shift lever in D to start the engine.
- HINT:
-
If the engine cranks slowly when the engine is restarted, it can be determined that the auxiliary 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 auxiliary 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 auxiliary battery fluid temperature at 11°C (52°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 auxiliary 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.
Depress the brake pedal and stop the vehicle.
Allow the engine to stop by stop and start control. (Keep the shift lever in D.)
Release the brake pedal with the shift lever in D to 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, perform learning of the external backup boost converter (eco run vehicle converter assembly).
·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.
·Inspect the fuses for circuits related to this system before performing the following procedure.
- HINT:
- ·
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.
·If electrical load from additional devices installed to the vehicle (aftermarket audio system, etc.) is applied to the B41, B42, AC42, IG12, IG31 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, AC42, IG12, IG31 or IG41 terminal in the engine stop and start ECU will not operate.
·If DTCs P279796 (Electromagnetic Oil Pump Component Internal Failure) and P323A19 (Backup Boost Converter "A" Circuit Current Above Threshold) are output simultaneously, troubleshoot for DTC P279796 first, as a malfunction which causes DTC P279796 to be stored may also cause DTC P323A19 to be stored.
·For wire harness and connector inspection procedures and precautions, refer to "General>INTRODUCTION>HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS>ELECTRONIC CIRCUIT INSPECTION PROCEDURE202201,999999,_V1,_107171,_0496334,RM100000001YK2F,"
·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.
PROCEDURE
Disconnect the A168 engine stop and start ECU connector.
Remove the BBC NO. 1 fuse and BBC NO. 2 fuse from the No. 1 engine room relay block.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition A168-1 (BIN2) - 2 (BBC NO. 2 fuse) Always Below 1 Ω A168-3 (BIN1) - 2 (BBC NO. 1 fuse) Always Below 1 Ω A168-1 (BIN2) - Body ground and other terminals Always 10 kΩ or higher 2 (BBC NO. 2 fuse holder) - Body ground and other terminals Always 10 kΩ or higher A168-3 (BIN1) - Body ground and other terminals Always 10 kΩ or higher 2 (BBC NO. 1 fuse holder) - Body ground and other terminals Always 10 kΩ or higher
- Result:
Proceed to OK NG
OK
NG
Disconnect the I230 engine stop and start ECU connector.
Disconnect the I4 combination meter assembly connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition I230-10 (IG12) - I4-38 (IG+) Always Below 1 Ω I230-10 (IG12) - Body ground and other terminals Always 10 kΩ or higher
- Result:
Proceed to OK NG
OK
NG
Disconnect the I230 engine stop and start ECU connector.
Disconnect the I21 power steering ECU assembly connector.
Disconnect the A151 skid control ECU (brake actuator assembly) connector.
Disconnect the I229 steering sensor connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition I230-23 (IG31) - I21-1 (IG) Always Below 1 Ω I230-23 (IG31) - A151-36 (IGR) Always Below 1 Ω I230-23 (IG31) - I229-9 (IGR) Always Below 1 Ω I230-23 (IG31) - Body ground and other terminals Always 10 kΩ or higher
- Result:
Proceed to OK NG
OK
NG
Check the vehicle specification
- Result:
Result Proceed to w/ Smart Entry and Start System A w/o Smart Entry and Start System B
A
B
Disconnect the I230 engine stop and start ECU connector.
Disconnect the O18 tire pressure warning ECU and receiver connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition I230-2 (B41) - O18-7 (+B) Always Below 1 Ω I230-3 (IG41) - O18-1 (IGR) Always Below 1 Ω I230-2 (B41) - Body ground and other terminals Always 10 kΩ or higher I230-3 (IG41) - Body ground and other terminals Always 10 kΩ or higher
- Result:
Proceed to OK NG
OK
NG
Check the vehicle specification
- Result:
Result Proceed to w/ Navigation System A w/o Navigation System B
A
B
Disconnect the I230 engine stop and start ECU connector.
Disconnect the I253 radio and display receiver assembly connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition I230-12 (B42) - I253-4 (+B1) Always Below 1 Ω I230-26 (AC42) - I253-16 (ACC1) Always Below 1 Ω I230-12 (B42) - Body ground and other terminals Always 10 kΩ or higher I230-26 (AC42) - Body ground and other terminals Always 10 kΩ or higher
- Result:
Proceed to OK NG
OK
NG
Check the vehicle specification
- Result:
Result Proceed to w/o Clearance Sonar System A w/ Clearance Sonar System B
A
B
Check air conditioning system specification
- Result:
Result Proceed to for Mechanical Control Type A for Electrical Control Type B
A
B
| *a | Component without harness connected
(Engine Stop and Start ECU) |
- | - |
Disconnect the A168, A169 and I230 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 I230-2 (B41) - A169-6 (DGND) Always 10 kΩ or higher I230-12 (B42) - A169-6 (DGND) Always 10 kΩ or higher I230-3 (IG41) - A169-6 (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 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
Disconnect the I230 engine stop and start ECU connector.
Disconnect the I37 air conditioning control assembly connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition I230-3 (IG41) - I37-9 (IG+) Always Below 1 Ω I230-3 (IG41) - Body ground and other terminals Always 10 kΩ or higher
- Result:
Proceed to OK NG
OK
NG
Disconnect the I230 engine stop and start ECU connector.
Disconnect the I24 clearance warning ECU assembly connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition I230-3 (IG41) - I24-1 (IG) Always Below 1 Ω I230-3 (IG41) - Body ground and other terminals Always 10 kΩ or higher
- Result:
Proceed to OK NG
OK
NG
Disconnect the I230 engine stop and start ECU connector.
Disconnect the I274 radio and display receiver assembly connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition I230-12 (B42) - I274-4 (+B1) Always Below 1 Ω I230-26 (AC42) - I274-16 (ACC1) Always Below 1 Ω I230-12 (B42) - Body ground and other terminals Always 10 kΩ or higher I230-26 (AC42) - Body ground and other terminals Always 10 kΩ or higher
- Result:
Proceed to OK NG
OK
NG
Disconnect the I230 engine stop and start ECU connector.
Disconnect the O124 tire pressure warning ECU and receiver connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition I230-2 (B41) - O124-7 (+B) Always Below 1 Ω I230-3 (IG41) - O124-1 (IGR) Always Below 1 Ω I230-2 (B41) - Body ground and other terminals Always 10 kΩ or higher I230-3 (IG41) - Body ground and other terminals Always 10 kΩ or higher
- Result:
Proceed to OK NG
OK
NG