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.
WIRING DIAGRAM
Refer to DTC P323A19.
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CAUTION / NOTICE / HINT
NOTICE:
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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 P323AA2 P323B29 P323B38 | Blinks | Converter output voltage cannot be boosted when the engine is restarted | A |
Auxiliary battery voltage drop | ||||||
Systems on the converter output side do not operate B43 terminal: Headup display system will not operate IG12 terminal: Meter / gauge system IG31 terminal: Both of the following will not operate
IG41 terminal: All of the following will not operate
| Overcurrent applied to an output terminal (output terminal relay circuit is shutoff) | Stop and start control is prohibited (Connected ECUs or sensors may detect power source malfunction DTCs) | P323A19 | Blinks | Systems do not operate as power supply from the converter is cut off | A |
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 | 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: All of the following will not operate
IG41 terminal: All of the following will not operate
B43 terminal: Headup display 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 P323AA2 P323B29 P323B38 | ||||||
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) | C |
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 | GO TO DIAGNOSTIC TROUBLE CODE CHART |
C | GO TO STEP 6 |
|
2. | CHECK HARNESS AND CONNECTOR (BIN1 AND BIN2 TERMINALS POWER SOURCE CIRCUIT) |
(a) Disconnect the A66 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 |
---|---|---|
A66-1 (BIN2) - Body ground | Always | 9.5 to 14 V |
A66-3 (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 AND IGP TERMINALS POWER SOURCE CIRCUIT) |
(a) Disconnect the H43 engine stop and start ECU connector.
(b) Turn the ignition switch to ON.
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection | Switch Condition | Specified Condition |
---|---|---|
H43-21 (IGR) - Body ground | Ignition switch ON | 9.5 to 14 V |
H43-18 (IGP) - Body ground | Ignition switch ON | 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 |
---|---|---|
H43-21 (IGR) - Body ground | Ignition switch off | 0 to 1 V |
H43-18 (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:
Meter Mirror Sub-assembly (w/ Headup Display) Tester Connection | Condition | Specified Condition |
---|---|---|
H43-11 (B43) - H61-2 (B) | Always | Below 1 Ω |
H43-3 (IG41) - H61-1 (IG) | Always | Below 1 Ω |
H43-11 (B43) - Body ground and other terminals | Always | 10 kΩ or higher |
H61-2 (B) - Body ground and other terminals | Always | 10 kΩ or higher |
H43-3 (IG41) - Body ground and other terminals | Always | 10 kΩ or higher |
H61-1 (IG) - Body ground and other terminals | Always | 10 kΩ or higher |
Tester Connection | Condition | Specified Condition |
---|---|---|
H43-10 (IG12) - H6-38 (IG+) | Always | Below 1 Ω |
H43-10 (IG12) - Body ground and other terminals | Always | 10 kΩ or higher |
H6-38 (IG+) - Body ground and other terminals | Always | 10 kΩ or higher |
Tester Connection | Condition | Specified Condition |
---|---|---|
H43-23 (IG31) - H1-1 (IG) | Always | Below 1 Ω |
H43-23 (IG31) - Body ground and other terminals | Always | 10 kΩ or higher |
H1-1 (IG) - Body ground and other terminals | Always | 10 kΩ or higher |
Tester Connection | Condition | Specified Condition |
---|---|---|
H43-3 (IG41) - H31-9 (IG+) | Always | Below 1 Ω |
H43-3 (IG41) - Body ground and other terminals | Always | 10 kΩ or higher |
H31-9 (IG+) - Body ground and other terminals | Always | 10 kΩ or higher |
Tester Connection | Condition | Specified Condition |
---|---|---|
H43-3 (IG41) - B8-8 (IGB) | Always | Below 1 Ω |
H43-3 (IG41) - Body ground and other terminals | Always | 10 kΩ or higher |
B8-8 (IGB) - Body ground and other terminals | Always | 10 kΩ or higher |
Tester Connection | Condition | Specified Condition |
---|---|---|
H43-23 (IG31) - A108-12 (IGR) | Always | Below 1 Ω |
H43-23 (IG31) - Body ground and other terminals | Always | 10 kΩ or higher |
A108-12 (IGR) - 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 |
---|---|---|
H61-2 (B) - Body ground*1 | Always | 10.5 to 16 V |
(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 |
---|---|---|
H61-1 (IG) - Body ground | Ignition switch ON | 10.5 to 16 V |
H6-38 (IG+) - Body ground | Ignition switch ON | 10.5 to 16 V |
H1-1 (IG) - Body ground | Ignition switch ON | 10.5 to 16 V |
H31-9 (IG+) - Body ground | Ignition switch ON | 10.5 to 16 V |
B8-8 (IGB) - Body ground*1 | Ignition switch ON | 10.5 to 16 V |
OK | CHECK POWER SOURCE CIRCUIT (POWER SOURCE CIRCUIT OF RELATED SYSTEM) |
NG | REPLACE ENGINE STOP AND START ECU |
6. | CHECK HARNESS AND CONNECTOR (BIN TERMINAL POWER SOURCE CIRCUIT) |
(a) Disconnect the 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 |
---|---|---|
A3-11 (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) - BATTERY) |
|
7. | CHECK HARNESS AND CONNECTOR (ACC TERMINAL POWER SOURCE CIRCUIT) |
(a) Disconnect the A3 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 |
---|---|---|
A3-3 (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 |
---|---|---|
A3-3 (ACC) - Body ground | Ignition switch off | 0 to 1 V |
NG | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
8. | CHECK HARNESS AND CONNECTOR (EXTERNAL BACKUP BOOST CONVERTER (ECO RUN VEHICLE CONVERTER ASSEMBLY) - BODY GROUND) |
(a) Disconnect the A3 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 | Switch Condition | Specified Condition |
---|---|---|
A3-6 (GND) - Body ground | Ignition switch ACC | Below 1 Ω |
NG | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
9. | CHECK HARNESS AND CONNECTOR (EXTERNAL BACKUP BOOST CONVERTER (ECO RUN VEHICLE CONVERTER ASSEMBLY) - STEREO COMPONENT EQUALIZER ASSEMBLY) |
(a) Disconnect the A3 external backup boost converter (eco run vehicle converter assembly) connector.
(b) Disconnect the O131 stereo component equalizer assembly connectors.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition |
---|---|---|
A3-5 (BO1) - O131-15 (+B) | Always | Below 1 Ω |
A3-12 (ACO) - O132-14 (ACC) | Always | Below 1 Ω |
A3-5 (BO1) - Body ground and other terminal | Always | Below 1 Ω |
O131-15 (+B) - Body ground and other terminal | Always | 10 kΩ or higher |
A3-12 (ACO) - Body ground and other terminal | Always | 10 kΩ or higher |
O131-14 (ACC) - Body ground and other terminal | Always | 10 kΩ or higher |
NG | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
10. | CHECK HARNESS AND CONNECTOR (STEREO COMPONENT EQUALIZER ASSEMBLY POWER SOURCE CIRCUIT) |
(a) Disconnect the O131 stereo component equalizer assembly connectors.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection | Condition | Specified Condition |
---|---|---|
O131-15 (+B) - Body ground | Always | 10.5 to 16 V |
(c) Turn the Ignition switch to ACC.
(d) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection | Switch Condition | Specified Condition |
---|---|---|
O131-14 (ACC) - Body ground | Ignition switch ACC | 10.5 to 16 V |
OK | GO TO ACTIVE NOISE CONTROL SYSTEM |
NG | REPLACE EXTERNAL BACKUP BOOST CONVERTER (ECO RUN VEHICLE CONVERTER ASSEMBLY) |
Automatic transaxle: Shift the selector lever to the P position and set the parking brake.
Press the push button start to turn off the engine. The ignition position is off.