Toyota Corolla Cross: Backup Boost Converter Circuit
DESCRIPTION
A backup boost converter is built into the engine stop and start ECU. The backup boost converter helps maintain the power source voltage when the engine is restarted by stop and start control.
This prevents various functions such as the audio and visual system from malfunctioning if the power source voltage drops due to the auxiliary battery voltage dropping when the engine is restarted by stop and start control.
If any DTCs are output, troubleshoot the DTCs first.
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
- Toyota Safety Sense
- Parking support brake system
WIRING DIAGRAM
Refer to DTC P323A00.
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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.
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- After replacing the engine stop and start ECU, perform learning of the external backup boost converter (eco run vehicle converter assembly).
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- 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.
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- Inspect the fuses for circuits related to this system before performing the following procedure.
HINT:
For wire harness and connector inspection procedures and precautions, refer to "
"
PROCEDURE
| 1. |
CHECK PROBLEM SYMPTOMS |
(a) Determine the trouble area by referring to the table below.
|
Effect on Vehicle | Trouble Area/Cause |
Fail-safe | DTC Output |
Stop and start cancel indicator |
Symptom | Proceed to |
|---|---|---|---|---|---|---|
|
When the engine is restarted by stop and start control: The following symptoms may occur
| Backup boost converter internal malfunction
| Stop and start control prohibited |
P323A00 P323B14 P323B29 P323B38 |
Does not come on (For Mexico Models: Blinks) |
Converter output voltage cannot be boosted when the engine is restarted |
A |
| Auxiliary battery voltage drop | ||||||
|
Systems do not operate (Due to converter input side malfunction) IGR terminal: All of the following will not operate
IGP terminal: The meter / gauge system will not operate ACC terminal: The Audio and visual system will not operate |
Converter input circuit malfunction
| Stop and start control prohibited |
- | Does not blink (Blinks when communication error DTCs are stored) |
Systems do not operate as power supply from the converter is cut off |
B |
| Systems on the converter output side do not operate (varies depending on the malfunctioning relay circuit the converter detected) IG12 terminal: The meter / gauge system will not operate IG31 terminal: The power steering system will not operate IG41 terminal: All of the following will not operate
B41 terminal: The tire pressure warning system will not operate |
Malfunction in circuits the converter supplies power to (between the converter and ECUs or sensors) |
Related systems do not operate as the relay circuit in the converter is turned off |
- | Does not blink (Blinks when communication error DTCs are stored) |
Systems do not operate as power supply from the converter is cut off |
B |
|
All of the following systems do not operate
|
| Stop and start control prohibited |
P061519 | Does not blink (Due to disabled meter / gauge system) |
All systems that the converter supplies power to do not operate (see circuit diagram) |
A |
| P30DF62 P30EF4B P323A00 P323A16 P323B14 P323B29 P323B38 | ||||||
| The audio does not operate (until the ignition switch is turned off) |
Excessive audio volume Data List item "State of BBC" displays "BBC Overcurrent" while the circuit is protected |
The relay circuit in the converter is turned off to cut off power supply to the audio and visual system (Returns to normal when the ignition switch is turned off) |
- | Does not blink |
If overcurrent is detected in the audio and visual system, system operation is disabled while the ignition switch is ON (Returns to normal when the ignition switch is turned off) |
C |
| The external backup boost converter (eco run vehicle converter assembly) output side system does not operate
|
| - |
- | Does not blink |
All systems that the converter supplies power to do not operate (see circuit diagram) |
D |
HINT: Varies depending on the number of times an open occurs in the +B circuit |
Converter circuit malfunction
| - |
- | Does not blink |
The converter cannot shut off the power source when the ignition switch is turned off |
B |
| Engine stop and start ECU power source circuit malfunction
| - |
- | Does not blink |
| B |
| A |
.gif) | GO TO DIAGNOSTIC TROUBLE CODE CHART |
| C |
| GO TO STEP 6 |
| D |
| GO TO STEP 7 |
|
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| 2. |
CHECK HARNESS AND CONNECTOR (BIN1 AND BIN2 TERMINALS POWER SOURCE CIRCUIT) |
(a) Disconnect the A168 engine stop and start ECU connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
A168-1 (BIN2) - Body ground |
Always | 9.5 to 14 V |
|
A168-3 (BIN1) - Body ground |
Always | 9.5 to 14 V |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE STOP AND START ECU - AUXILIARY BATTERY) |
|
| 3. |
CHECK HARNESS AND CONNECTOR (IGR, IGP AND ACC TERMINALS POWER SOURCE CIRCUIT) |
(a) Disconnect the I230 engine stop and start ECU connector.
(b) Turn the ignition switch ACC.
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection | Switch Condition |
Specified Condition |
|---|---|---|
|
I230-19 (ACC) - Body ground |
Ignition switch ACC | 9.5 to 14 V |
(d) Turn the ignition switch to ON.
(e) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection | Switch Condition |
Specified Condition |
|---|---|---|
|
I230-21 (IGR) - Body ground |
Ignition switch ON | 9.5 to 14 V |
|
I230-18 (IGP) - Body ground |
Ignition switch ON | 9.5 to 14 V |
(f) Turn the ignition switch to off.
(g) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection | Switch Condition |
Specified Condition |
|---|---|---|
|
I230-19 (ACC) - Body ground |
Ignition switch off | 0 to 1 V |
|
I230-21 (IGR) - Body ground |
Ignition switch off | 0 to 1 V |
|
I230-18 (IGP) - Body ground |
Ignition switch off | 0 to 1 V |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
| 4. |
CHECK HARNESS AND CONNECTOR (ENGINE STOP AND START ECU - EACH ECU OR SENSOR) |
(a) Disconnect the connector from the corresponding system ECU/sensor.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tire Pressure Warning ECU and Receiver (w/o Smart Key System)|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
I230-2 (B41) - O221-7 (+B) |
Always | Below 1 Ω |
|
I230-3 (IG41) - O221-1 (IGR) |
Always | Below 1 Ω |
|
I230-2 (B41) - Body ground and other terminals |
Always | 10 kΩ or higher |
|
O221-7 (+B) - Body ground and other terminals |
Always | 10 kΩ or higher |
|
I230-3 (IG41) - Body ground and other terminals |
Always | 10 kΩ or higher |
|
O221-1 (IGR) - Body ground and other terminals |
Always | 10 kΩ or higher |
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
I230-2 (B41) - O209-7 (+B) |
Always | Below 1 Ω |
|
I230-3 (IG41) - O209-1 (IGR) |
Always | Below 1 Ω |
|
I230-2 (B41) - Body ground and other terminals |
Always | 10 kΩ or higher |
|
O209-7 (+B) - Body ground and other terminals |
Always | 10 kΩ or higher |
|
I230-3 (IG41) - Body ground and other terminals |
Always | 10 kΩ or higher |
|
O209-1 (IGR) - Body ground and other terminals |
Always | 10 kΩ or higher |
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
I230-10 (IG12) - I4-6 (IG+) |
Always | Below 1 Ω |
|
I230-10 (IG12) - Body ground and other terminals |
Always | 10 kΩ or higher |
|
I4-6 (IG+) - Body ground and other terminals |
Always | 10 kΩ or higher |
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
I230-23 (IG31) - I21-1 (IG) |
Always | Below 1 Ω |
|
I230-23 (IG31) - Body ground and other terminals |
Always | 10 kΩ or higher |
|
I21-1 (IG) - Body ground and other terminals |
Always | 10 kΩ or higher |
|
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 |
|
I24-1 (IG) - Body ground and other terminals |
Always | 10 kΩ or higher |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
| 5. |
CHECK ENGINE STOP AND START ECU (OUTPUT VOLTAGE FOR EACH SYSTEM) |
(a) Disconnect the connector from the corresponding system ECU/sensor.
(b) Measure the voltage according to the value(s) in the table below.
HINT:
Measure the voltage at the corresponding terminals.
Standard Voltage:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
O221-7 (+B) - Body ground*1 |
Always | 10.5 to 16 V |
|
O209-7 (+B) - Body ground*2 |
Always | 10.5 to 16 V |
- *1: w/o Smart Key System
- *2: w/ Smart Key System
(c) Turn the ignition switch to ON.
(d) Measure the voltage according to the value(s) in the table below.
HINT:
Measure the voltage at the corresponding terminals.
Standard Voltage:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
O221-1 (IGR) - Body ground*1 |
Ignition switch ON | 10.5 to 16 V |
|
O209-1 (IGR) - Body ground*2 |
Ignition switch ON | 10.5 to 16 V |
|
I24-1 (IG) - Body ground*3 |
Ignition switch ON | 10.5 to 16 V |
- *1: w/o Smart Key System
- *2: w/ Smart Key System
- *3: w/ Clearance Sonar System
| OK | | CHECK POWER SOURCE CIRCUIT (POWER SOURCE CIRCUIT OF RELATED SYSTEM) |
| NG | | REPLACE ENGINE STOP AND START ECU |
| 6. |
CHECK AUDIO AND VISUAL SYSTEM |
(a) Turn the ignition switch off and wait for 1 minute.
(b) Turn the ignition switch to ON.
(c) Lower the audio volume.
(d) Check if the audio and visual system operates normally.
OK:
Audio and visual system operates normally.
| OK | | END |
| NG | | GO TO AUDIO AND VISUAL SYSTEM |
| 7. |
CHECK HARNESS AND CONNECTOR (BIN TERMINAL POWER SOURCE CIRCUIT) |
(a) Disconnect the A166 external backup boost converter (eco run vehicle converter assembly) connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
A166-11 (BIN) - Body ground |
Always | 9.5 to 14 V |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR (EXTERNAL BACKUP BOOST CONVERTER (ECO RUN VEHICLE CONVERTER ASSEMBLY) - AUXILIARY BATTERY) |
|
| 8. |
CHECK HARNESS AND CONNECTOR (ACC TERMINAL POWER SOURCE CIRCUIT) |
(a) Disconnect the A166 external backup boost converter (eco run vehicle converter assembly) connector.
(b) Turn the ignition switch to ACC.
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection | Switch Condition |
Specified Condition |
|---|---|---|
|
A166-3 (ACC) - Body ground |
Ignition switch ACC | 9.5 to 14 V |
(d) Turn the ignition switch to off.
(e) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection | Switch Condition |
Specified Condition |
|---|---|---|
|
A166-3 (ACC) - Body ground |
Ignition switch off | 0 to 1 V |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
| 9. |
CHECK HARNESS AND CONNECTOR (EXTERNAL BACKUP BOOST CONVERTER (ECO RUN VEHICLE CONVERTER ASSEMBLY) - BODY GROUND) |
(a) Disconnect the external backup boost converter (eco run vehicle converter assembly) connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
A166-6 (GND) - Body ground |
Always | Below 1 Ω |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
| 10. |
CHECK HARNESS AND CONNECTOR (EXTERNAL BACKUP BOOST CONVERTER (ECO RUN VEHICLE CONVERTER ASSEMBLY) - STEREO COMPONENT AMPLIFIER ASSEMBLY) |
(a) Disconnect the external backup boost converter (eco run vehicle converter assembly) connector.
(b) Disconnect the stereo component amplifier assembly connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Stereo Component Equalizer Assembly|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
A166-5 (BO1) - I233-1 (+B) |
Always | Below 1 Ω |
|
A166-5 (BO1)or I233-1 (+B) - Body ground and other terminals |
Always | 10 kΩ or higher |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
| 11. |
CHECK EXTERNAL BACKUP BOOST CONVERTER (ECO RUN VEHICLE CONVERTER ASSEMBLY) (OUTPUT VOLTAGE FOR STEREO COMPONENT AMPLIFIER ASSEMBLY) |
(a) Disconnect the stereo component amplifier assembly connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
I233-1 (+B) - Body ground |
Ignition switch ACC | 10.5 to 16 V |
| OK | | CHECK POWER SOURCE CIRCUIT (POWER SOURCE CIRCUIT OF RELATED SYSTEM) |
| NG | | REPLACE EXTERNAL BACKUP BOOST CONVERTER (ECO RUN VEHICLE CONVERTER ASSEMBLY) |
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This procedure is for when the stop and start system does not operate.
Regarding explanations of the features of stop and start system control:
Click here
PROCEDURE
1
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Installation
INSTALLATION CAUTION / NOTICE / HINT COMPONENTS (INSTALLATION)
Procedure Part Name Code
1 REAR WIPER MOTOR GROMMET
85143R
- -
2 REAR WIPER MOTOR ASSEMBLY
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3 INSTALL REAR WIPER ARM AND BLADE ASSEMBLY
