Lexus ES: Brake Switch "A" Signal Compare Failure (P057162)
DESCRIPTION
When the brake pedal is depressed, the stop light switch assembly outputs a signal to the hybrid vehicle control ECU. The hybrid vehicle control ECU uses this signal to control cancellation of vehicle speed by the dynamic radar cruise control. When the hybrid vehicle control ECU determines that terminals STP and ST1 of the stop light switch assembly are both less than 1 V, DTC P057162 is stored.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | DTC Output from |
|---|---|---|---|---|---|
| P057162 | Brake Switch "A" Signal Compare Failure | When the power switch is on (IG) and the dynamic radar cruise control system is operating, the hybrid vehicle control ECU detects that the voltage at terminal STP and ST1- are both less than 1 V for approximately 0.5 seconds or more. |
| Does not come on | Hybrid Control |
WIRING DIAGRAM
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CAUTION / NOTICE / HINT
NOTICE:
- Inspect the fuses for circuits related to this system before performing the following procedure.
-
Before replacing the hybrid vehicle control ECU, refer to Registration.
Click here
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PROCEDURE
| 1. | CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - AUXILIARY BATTERY AND BODY GROUND) |
| (a) Disconnect the A80 stop light switch assembly connector. |
|
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A80-2 (GND) - Body ground | Always | Below 1 Ω |
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A80-7 (B) - Body ground | Always | 11 to 14 V |
| A80-6 (B) - Body ground | Power switch on (IG) | 11 to 14 V |
| A80-6 (B) - Body ground | Power switch off | Below 1 V |
(d) Connect the A80 stop light switch assembly connector.
| NG | .gif) | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
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| 2. | INSPECT STOP LIGHT SWITCH ASSEMBLY |
(a) Inspect the stop light switch assembly.
Click here
| NG | | REPLACE STOP LIGHT SWITCH ASSEMBLY |
|
| 3. | CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - STOP LIGHT SWITCH ASSEMBLY) |
(a) Disconnect the A32 and A33 hybrid vehicle control ECU connectors.
(b) Disconnect the A80 stop light switch assembly connector.
(c) Disconnect the A45 skid control ECU (brake booster with master cylinder assembly) connector.
(d) Disconnect the N9 certification ECU (smart key ECU assembly) connector.
(e) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A33-28 (ST1-) - A80-5 (L) | Always | Below 1 Ω |
| A32-15 (STP) - A80-3 (L) | Always | Below 1 Ω |
| A33-28 (ST1-) or A80-5 (L) - Body ground | Always | 10 kΩ or higher |
| A32-15 (STP) or A80-3 (L) - Body ground | Always | 10 kΩ or higher |
(f) Connect the N9 certification ECU (smart key ECU assembly) connector.
(g) Connect the A45 skid control ECU (brake booster with master cylinder assembly) connector.
(h) Connect the A80 stop light switch assembly connector.
(i) Connect the A32 and A33 hybrid vehicle control ECU connectors.
| OK | | REPLACE HYBRID VEHICLE CONTROL ECU |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
