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 ECM. The ECM uses this signal to control cancellation of vehicle speed by the dynamic radar cruise control. When the ECM 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 engine switch is on (IG) and the dynamic radar cruise control system is operating, the ECM 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 | Engine |
WIRING DIAGRAM
for 2GR-FKS
for A25A-FKS
CAUTION / NOTICE / HINT
NOTICE:
- Inspect the fuses for circuits related to this system before performing the following procedure.
-
Before replacing the ECM, refer to Registration.
Click here
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PROCEDURE
| 1. | CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - 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 | Engine switch on (IG) | 11 to 14 V |
| A80-6 (B) - Body ground | Engine 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.
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| NG | | REPLACE STOP LIGHT SWITCH ASSEMBLY |
|
| 3. | CHECK HARNESS AND CONNECTOR (ECM - STOP LIGHT SWITCH ASSEMBLY) |
(a) Disconnect the A25 ECM connector.*1
(b) Disconnect the A28 ECM connector.*2
(c) Disconnect the A80 stop light switch assembly connector.
(d) Disconnect the A40 skid control ECU (brake actuator assembly) connector.
(e) Disconnect the N9 certification ECU (smart key ECU assembly) connector.
(f) Disconnect the G25 shift lock control ECU (shift lock control unit assembly) connector.
- *1: for 2GR-FKS
- *2: for A25A-FKS
(g) Measure the resistance according to the value(s) in the table below.
Standard Resistance (for 2GR-FKS):
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A25-42 (ST1-) - A80-5 (L) | Always | Below 1 Ω |
| A25-27 (STP) - A80-3 (L) | Always | Below 1 Ω |
| A25-42 (ST1-) or A80-5 (L) - Body ground | Always | 10 kΩ or higher |
| A25-27 (STP) or A80-3 (L) - Body ground | Always | 10 kΩ or higher |
Standard Resistance (for A25A-FKS):
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| A28-22 (ST1-) - A80-5 (L) | Always | Below 1 Ω |
| A28-21 (STP) - A80-3 (L) | Always | Below 1 Ω |
| A28-22 (ST1-) or A80-5 (L) - Body ground | Always | 10 kΩ or higher |
| A28-21 (STP) or A80-3 (L) - Body ground | Always | 10 kΩ or higher |
(h) Connect the G25 shift lock control ECU (shift lock control unit assembly) connector.
(i) Connect the N9 certification ECU (smart key ECU assembly) connector.
(j) Connect the A40 skid control ECU (brake actuator assembly) connector.
(k) Connect the A80 stop light switch assembly connector.
(l) Connect the A25 ECM connector.*1
(m) Connect the A28 ECM connector.*2
- *1: for 2GR-FKS
- *2: for A25A-FKS
| OK | | REPLACE ECM |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
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Click here
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