DTC P323A-19: Backup Boost Converter "A" Circuit Current Above Threshold [11/2016 - ]: Procedure
WARNING: This page is about a different car, the 2019 Toyota Highlander, 2018 Toyota Highlander, and 2017 Toyota Highlander. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P323A19)
- Connect the Techstream to the DLC3.
- Turn the ignition switch to ON.
- Turn the Techstream on.
- Enter the following menus: Powertrain / Stop and Start / Trouble Codes.
- Read the DTCs.
Powertrain > Stop and Start > Trouble Codes
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.
Result:
B
GO TO DTC P279612, P279614 OR P279796. Refer to DIAGNOSTIC TROUBLE CODE CHART [11/2016 - ] .
Result:
A
Go to next step
- CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - BBC FUSE AND BBC NO. 2 FUSE)
- Disconnect the engine stop and start ECU connector.
- Remove the BBC fuse and BBC NO. 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 A91-1 (BIN2) - BBC fuse terminal 2 Always Below 1 Ω A91-3 (BIN1) - BBC NO. 2 fuse terminal 2 Always Below 1 Ω A91-1 (BIN2) or BBC fuse terminal 2 - Body ground and other terminals Always 10 kΩ or higher A91-3 (BIN1) or BBC NO. 2 fuse terminal 2 - Body ground and other terminals Always 10 kΩ or higher Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
Go to next step
- CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - EACH ECU OR SENSOR)
- Disconnect the engine stop and start ECU connector.
- Disconnect the forward recognition camera connector. (w/ Toyota Safety Sense P)
- Disconnect the driving support ECU assembly connector. (w/ Toyota Safety Sense P)
- Disconnect the millimeter wave radar sensor assembly connector. (w/ Toyota Safety Sense P)
- Disconnect the tire pressure warning ECU and receiver connector.
- Disconnect the radio and display receiver assembly connector. (w/ Radio and Display Receiver Assembly)
- Disconnect the television display assembly connector. (w/ Rear Seat Entertainment System)
- Disconnect the navigation receiver assembly connector. (w/ Navigation Receiver Assembly)
- Disconnect the parking assist ECU connector. (w/ Panoramic View Monitor System)
- Disconnect the blind spot monitor sensor LH connector. (w/ Blind Spot Monitor System)
- Disconnect the blind spot monitor sensor RH connector. (w/ Blind Spot Monitor System)
- Disconnect the central gateway ECU (network gateway ECU) connector.
- Disconnect the inner rear view mirror assembly connector. (w/ EC Mirror)
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition F123-3 (IG41) - S14-8 (IGB)*1 Always Below 1 Ω F123-3 (IG41) - F126-7 (B)*1 Always Below 1 Ω F123-3 (IG41) - A81-8 (IGB)*1 Always Below 1 Ω F123-3 (IG41) - M25-1 (IG)*2 Always Below 1 Ω F123-3 (IG41) - M43-1 (IG)*3 Always Below 1 Ω F123-3 (IG41) - M31-5 (BLB)*4 Always Below 1 Ω F123-3 (IG41) - L23-5 (BRB)*4 Always Below 1 Ω F123-3 (IG41) - F129-6 (IG)*5 Always Below 1 Ω F123-3 (IG41) - F135-11 (IG1) Always Below 1 Ω F123-3 (IG41) - S15-1 (IG)*6*7 Always Below 1 Ω F123-3 (IG41) - S16-1 (IG)*1*7 Always Below 1 Ω F123-2 (B41) - M25-7 (+B)*2 Always Below 1 Ω F123-2 (B41) - M43-7 (+B)*3 Always Below 1 Ω F123-2 (B41) - F129-2 (+B)*5 Always Below 1 Ω F123-12 (B42) - F69-4 (+B1)*8 Always Below 1 Ω F123-12 (B42) - F114-4 (+B1)*9 Always Below 1 Ω F123-11 (B43) - S8-1 (+B)*10 Always Below 1 Ω F123-3 (IG41) or S14-8 (IGB)*1 - Body ground and other terminals Always 10 kΩ or higher F123-3 (IG41) or F126-7 (B)*1 - Body ground and other terminals Always 10 kΩ or higher F123-3 (IG41) or A81-8 (IGB)*1 - Body ground and other terminals Always 10 kΩ or higher F123-3 (IG41) or M25-1 (IG)*2 - Body ground and other terminals Always 10 kΩ or higher F123-3 (IG41) or M43-1 (IG)*3 - Body ground and other terminals Always 10 kΩ or higher F123-3 (IG41) or M31-5 (BLB)*4 - Body ground and other terminals Always 10 kΩ or higher F123-3 (IG41) or L23-5 (BRB)*4 - Body ground and other terminals Always 10 kΩ or higher F123-3 (IG41) or F129-6 (IG)*5 - Body ground and other terminals Always 10 kΩ or higher F123-3 (IG41) or F135-11 (IG1) - Body ground and other terminals Always 10 kΩ or higher F123-3 (IG41) or S15-1 (IG)*6*7 - Body ground and other terminals Always 10 kΩ or higher F123-3 (IG41) or S16-1 (IG)*1*7 - Body ground and other terminals Always 10 kΩ or higher F123-2 (B41) or M25-7 (+B)*2 - Body ground and other terminals Always 10 kΩ or higher F123-2 (B41) or M43-7 (+B)*3 - Body ground and other terminals Always 10 kΩ or higher F123-2 (B41) or F129-2 (+B)*5 - Body ground and other terminals Always 10 kΩ or higher F123-12 (B42) or F69-4 (+B1)*8 - Body ground and other terminals Always 10 kΩ or higher F123-12 (B42) or F114-4 (+B1)*9 - Body ground and other terminals Always 10 kΩ or higher F123-11 (B43) or S8-1 (+B)*10 - Body ground and other terminals Always 10 kΩ or higher - *1: w/ Toyota Safety Sense P
- *2: w/o Smart Key System
- *3: w/ Smart Key System
- *4: w/ Blind Spot Monitor System
- *5: w/ Panoramic View Monitor System
- *6: w/o Toyota Safety Sense P
- *7: w/ EC Mirror
- *8: w/ Radio and Display Receiver Assembly
- *9: w/ Navigation Receiver Assembly
- *10: w/ Rear Seat Entertainment System
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
Go to next step
- CHECK ENGINE STOP AND START ECU
*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 F123-2 (B41) - A92-6 (DGND) Always 10 kΩ or higher F123-3 (IG41) - A92-6 (DGND) Always 10 kΩ or higher F123-11 (B43) - A92-6 (DGND) Always 10 kΩ or higher F123-12 (B42) - A92-6 (DGND) Always 10 kΩ or higher Proceed to OK NG
Result:
NG
REPLACE ENGINE STOP AND START ECU. Refer to REMOVAL [11/2016 - ] .
Result:
OK
Go to next step
- CHECK VEHICLE CONDITION (B41, B42, B43 OR IG41 CIRCUIT)
- 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 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
Result:
A
TROUBLESHOOT ECUS CONNECTED TO TERMINALS B41, B42, B43 AND IG41
Result:
B
END (REMOVE ADDITIONAL DEVICE)
- 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.