Toyota Corolla Cross: Brake Switch "A"/"B" Signal Cross Coupled (P05042B)
DESCRIPTION
The stop light switch assembly is a duplex system that transmits two signals: STP and ST1-. These two signals are used by the hybrid vehicle control ECU to monitor whether or not the brake system is working properly. If the signals, which indicate the brake pedal is being depressed and released, are detected simultaneously, the hybrid vehicle control ECU interprets this as a malfunction in the stop light switch assembly and stores this DTC.
HINT:
The normal signal conditions are as shown in the table below.
|
Signal (hybrid vehicle control ECU Terminal) |
Brake Pedal Released |
In Transition | Brake Pedal Depressed |
|---|---|---|---|
|
STP | OFF |
ON | ON |
|
ST1- | ON |
ON | OFF |
- [OFF] denotes ground potential.
- [ON] denotes auxiliary battery potential (+B).
On the GTS, Data List item Stop Light SW is ON when the brake pedal is depressed.
|
DTC No. | Detection Item |
DTC Detection Condition |
Trouble Area | MIL |
Warning Indicate | Note |
|---|---|---|---|---|---|---|
|
P05042B | Brake Switch "A"/"B" Signal Cross Coupled |
Conditions (a) and (b) are met for 0.5 seconds or more (1 trip detection logic): (a) Ignition switch ON (b) STP signal OFF when ST1- signal OFF |
| Does not come on |
Master Warning: Does not come on |
SAE Code: P0504 |
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
Inspect the fuses for circuits related to this system before performing the following procedure.
HINT:
- Stop light switch assembly conditions can be checked using the GTS.
- Enter the following menus: Powertrain / Hybrid Control / Data List / Stop Light SW.
- Check the Data List indication when the brake pedal is depressed and released.
Brake Pedal Operation
Stop Light SW
Depressed
ON
Released
OFF
- Read Freeze Frame Data using the GTS. The ECM records vehicle and driving condition information as Freeze Frame Data the moment a DTC is stored. When troubleshooting, Freeze Frame Data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
PROCEDURE
|
1. | CHECK TERMINAL VOLTAGE (POWER SOURCE OF STOP LIGHT SWITCH ASSEMBLY) |
(a) Disconnect the stop light switch assembly connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
A53-7 (B) - Body ground |
Always | 11 to 14 V |
(c) Reconnect the stop light switch assembly connector.
| NG | .gif) | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
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|
2. | CHECK TERMINAL VOLTAGE (POWER SOURCE OF STOP LIGHT SWITCH ASSEMBLY) |
(a) Disconnect the stop light switch assembly 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 | Condition |
Specified Condition |
|---|---|---|
|
A53-6 (B) - Body ground |
Ignition switch ON |
11 to 14 V |
(d) Turn the ignition switch off.
(e) Reconnect the stop light switch assembly connector.
| NG | | GO TO STEP 6 |
|
|
3. | CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BODY GROUND) |
(a) Disconnect the 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 |
|---|---|---|
|
A53-2 (GND) - Body ground |
Always | Below 1 Ω |
(c) Reconnect the stop light switch assembly connector.
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
4. | CHECK TERMINAL VOLTAGE (STP AND ST1- VOLTAGE) |
(a) Disconnect the hybrid vehicle control ECU connector.
(b) Turn the ignition switch to ON.
(c) Measure the voltage according to the value(s) in the table below.
|
*a | Brake Pedal Depressed |
*b | Brake Pedal Released |
|
*c | Front view of wire harness connector (to Hybrid Vehicle Control ECU) |
- | - |
Standard Voltage:
|
Tester Connection | Brake Pedal Operation |
Specified Condition |
|---|---|---|
|
A192-7 (ST1-) - Body ground |
Released | 7.5 to 14 V |
|
Depressed | Below 1.5 V | |
|
A192-22 (STP) - Body ground |
Released | Below 1.5 V |
|
Depressed | 7.5 to 14 V |
(d) Turn the ignition switch off.
(e) Reconnect the hybrid vehicle control ECU connector.
| OK | | REPLACE HYBRID VEHICLE CONTROL ECU |
|
|
5. | CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - HYBRID VEHICLE CONTROL ECU) |
(a) Disconnect the stop light switch assembly connector.
(b) Disconnect the hybrid vehicle control ECU connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
A192-7 (ST1-) - A53-5 (L) |
Always | Below 1 Ω |
|
A192-22 (STP) - A53-3 (L) |
Always | Below 1 Ω |
|
A192-7 (ST1-) or A53-5 (L) - Body ground and other terminals |
Always | 10 kΩ or higher |
|
A192-22 (STP) or A53-3 (L) - Body ground and other terminals |
Always | 10 kΩ or higher |
(d) Reconnect the hybrid vehicle control ECU connector.
(e) Reconnect the stop light switch assembly connector.
| OK | | REPLACE STOP LIGHT SWITCH ASSEMBLY |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
6. | CHECK HARNESS AND CONNECTOR (IGP-MAIN RELAY - STOP LIGHT SWITCH ASSEMBLY) |
(a) Remove the IGP-MAIN relay from the No. 1 engine room relay block and No. 1 junction block assembly.
(b) Disconnect the stop light switch assembly connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
3 (IGP-MAIN relay holder) - A53-6 (B) |
Always | Below 1 Ω |
|
3 (IGP-MAIN relay holder) or A53-6 (B) - Body ground and other terminals |
Always | 10 kΩ or higher |
(d) Reconnect the stop light switch assembly connector.
(e) Install the IGP-MAIN relay.
| OK | | CHECK ECU POWER SOURCE CIRCUIT |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
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