Dtc P0504 Brake Switch A / B Correlation
DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
CHECK STOP LIGHT SWITCH ASSEMBLY (TERMINAL VOLTAGE)
CHECK STOP LIGHT SWITCH ASSEMBLY (TERMINAL VOLTAGE)
INSPECT STOP LIGHT SWITCH ASSEMBLY
CHECK ECM (STP AND ST1- VOLTAGE)
CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - IGNITION SWITCH ASSEMBLY)
DTC P0504 Brake Switch "A" / "B" Correlation |
DESCRIPTION
The stop light switch is a duplex system that transmits two signals: STP and ST1-. These two signals are used by the ECM to monitor whether or not the brake system is working properly. If signals which indicate the brake pedal is being depressed and released are detected simultaneously, the ECM interprets this as a malfunction in the stop light switch and stores the DTC.- HINT:
- The normal signal conditions are as shown in the table below.
Signal (ECM Terminal)
| Brake Pedal Released
| In Transition
| Brake Pedal Depressed
|
STP
| OFF
| ON
| ON
|
ST1-
| ON
| ON
| OFF
|
- [OFF] denotes ground potential.
- [ON] denotes battery potential (+B).
- On the intelligent tester, both the Data List items Stop Light Switch and ST1 are ON when the brake pedal is depressed because the ST1 indication characteristic is opposite to the Stop Light Switch indication.
DTC No.
| DTC Detection Condition
| Trouble Area
|
P0504
| Conditions (a), (b) and (c) continue for 0.5 seconds or more (1 trip detection logic):
(a) The ignition switch is ON.
(b) The brake pedal is released.
(c) The STP signal is off when the ST1- signal is off.
| - Open or short in stop light switch assembly signal circuit
- Stop light switch assembly
- ECM
|
WIRING DIAGRAM
INSPECTION PROCEDURE
- HINT:
- Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. 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.
- STP signal conditions can be checked using the intelligent tester.
- Connect the intelligent tester to the DLC3.
- Turn the ignition switch to ON.
- Turn the intelligent tester on.
- Enter the following menus: Powertrain / Engine and ECT / All Data / Stop Light Switch and ST1.
- Check the Data List indication when the brake pedal is depressed and released.
Brake Pedal Operation
| Stop Light Switch
| ST1
|
Depressed
| ON
| ON
|
Released
| OFF
| OFF
|
- NOTICE:
- Inspect the fuses for circuits related to this system before performing the following inspection procedure.
| 1.CHECK STOP LIGHT SWITCH ASSEMBLY (TERMINAL VOLTAGE) |
Disconnect the stop light switch assembly connector.
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
Tester Connection
| Switch Condition
| Specified Condition
|
A24-3 - Body ground
| Ignition switch ON
| 11 to 14 V
|
Text in Illustration*a
| Front view of wire harness connector
(to Stop Light Switch Assembly)
|
Reconnect the stop light switch assembly connector.
| 2.CHECK STOP LIGHT SWITCH ASSEMBLY (TERMINAL VOLTAGE) |
Disconnect the stop light switch assembly connector.
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
Tester Connection
| Condition
| Specified Condition
|
A24-2 - Body ground
| Always
| 11 to 14 V
|
Text in Illustration*a
| Front view of wire harness connector
(to Stop Light Switch Assembly)
|
Reconnect the stop light switch assembly connector.
| | REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BATTERY) |
|
|
| 3.INSPECT STOP LIGHT SWITCH ASSEMBLY |
Inspect the stop light switch assembly.
Measure the voltage according to the value(s) in the table below.
- Standard Resistance:
Tester Connection
| Switch Condition
| Specified Condition
|
1 - 2
| Pin not pushed
| Below 1 Ω
|
3 - 4
| Pin not pushed
| 10 kΩ or higher
|
1 - 2
| Pin pushed
| 10 kΩ or higher
|
3 - 4
| Pin pushed
| Below 1 Ω
|
| 4.CHECK ECM (STP AND ST1- VOLTAGE) |
Disconnect the ECM connector.
Turn the ignition switch to ON.
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
Tester Connection
| Brake Pedal Operation
| Specified Condition
|
G145-8 (ST1-) - Body ground
| Brake pedal released
| 7.5 to 14 V
|
Brake pedal depressed
| Below 1.5 V
|
G146-18 (STP) - Body ground
| Brake pedal released
| Below 1.5 V
|
Brake pedal depressed
| 7.5 to 14 V
|
Text in Illustration*a
| Component with harness connected
(ECM)
|
Reconnect the ECM connector.
| | REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - ECM) |
|
|
| 5.CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - IGNITION SWITCH ASSEMBLY) |
Disconnect the stop light switch assembly connector.
Disconnect the ignition switch connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance (Check for Open):
Tester Connection
| Condition
| Specified Condition
|
A24-3 - G9-6 (IG2)
| Always
| Below 1 Ω
|
- Standard Resistance (Check for Short):
Tester Connection
| Condition
| Specified Condition
|
A24-3 or G9-6 (IG2) - Body ground
| Always
| 10 kΩ or higher
|
Reconnect the ignition switch connector.
Reconnect the stop light switch assembly connector.
| | REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - IGNITION SWITCH ASSEMBLY) |
|
|
