2NZ-FE ENGINE CONTROL  SFI SYSTEM  P0504  Brake Switch "A" / "B" Correlation  


DESCRIPTION

The stop light switch assembly 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 the 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 assembly and stores this 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 GTS, 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. Detection Item DTC Detection Condition Trouble Area MIL Memory
P0504 Brake Switch "A" / "B" Correlation Conditions (a) and (b) continue for 0.5 seconds or more (1 trip detection logic):
(a) Ignition switch ON
(b) STP signal OFF when ST1- signal OFF
·

Open or short in stop light switch signal circuit

·

Stop light switch assembly

·

ECM


Does not come on DTC stored

WIRING DIAGRAM

A311078E64
5.813,0.74 6.271,0.938 0.458,0.198 10 false A56 5.813,1.26 6.271,1.458 0.458,0.198 10 false A56 5.802,1.698 6.26,1.896 0.458,0.198 10 false A56 5.813,2.51 6.271,2.708 0.458,0.198 10 false B56 6.177,0.76 6.635,0.958 0.458,0.198 10 false IGSW 6.177,1.26 6.635,1.458 0.458,0.198 10 false ST1- 6.177,1.708 6.635,1.906 0.458,0.198 10 false STP 6.177,2.51 6.635,2.708 0.458,0.198 10 false E1 6.344,3.073 6.802,3.271 0.458,0.198 10 false ECM 3.698,2.375 4.156,2.573 0.458,0.198 10 false A1 3.688,2.531 5.552,2.781 1.865,0.25 10 false Stop Light Switch Assembly 2.906,0.927 3.365,1.125 0.458,0.198 10 false IGN 1.698,1.427 2.156,1.625 0.458,0.198 10 false IG2 2.188,1 2.646,1.198 0.458,0.198 10 false 1 2.188,0.646 2.646,0.844 0.458,0.198 10 false 5 1.406,1 1.865,1.198 0.458,0.198 10 false 2 1.427,0.646 1.885,0.844 0.458,0.198 10 false 3 0.417,2.104 0.875,2.302 0.458,0.198 10 false IG2 0.875,3.531 1.333,3.729 0.458,0.198 10 false ALT 1.646,3.531 2.104,3.729 0.458,0.198 10 false STOP 0.396,3.875 1.531,4.146 1.135,0.271 10 false FL MAIN 0.604,4.573 1.74,4.844 1.135,0.271 10 false Battery 3.969,3.854 6.563,4.135 2.594,0.281 10 false from Ignition Switch Assembly 5.823,2.323 6.198,2.5 0.375,0.177 10 false 104 5.854,1.531 6.229,1.708 0.375,0.177 10 false 36 5.844,1.083 6.219,1.26 0.375,0.177 10 false 35 5.854,0.563 6.229,0.74 0.375,0.177 10 false 28 4.344,1.708 4.521,1.948 0.177,0.24 10 false B 4.344,1.271 4.521,1.51 0.177,0.24 10 false B 4.99,1.271 5.146,1.51 0.156,0.24 10 false L 5,1.719 5.427,1.906 0.427,0.188 10 false L 4.792,2.125 5.219,2.313 0.427,0.188 10 false GND 4.188,1.177 4.563,1.354 0.375,0.177 10 false 5 4.188,1.615 4.563,1.792 0.375,0.177 10 false 1 5.188,1.177 5.563,1.354 0.375,0.177 10 false 4 5.188,1.625 5.563,1.802 0.375,0.177 10 false 2 5.188,2.031 5.563,2.208 0.375,0.177 10 false 3

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following procedure.


HINT:
·

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.

·

Stop light switch assembly conditions can be checked using the GTS.

1.

Connect the GTS to the DLC3.

2.

Turn the ignition switch to ON.

3.

Turn the GTS on.

4.

Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Stop Light Switch and ST1.

5.

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




PROCEDURE

1.CHECK TERMINAL VOLTAGE (POWER SOURCE OF STOP LIGHT SWITCH ASSEMBLY)
A312702C01
0.396,2.052 0.771,2.323 0.375,0.271 1.313,2.125 0.938,1.375 0.938,1.375 0.708,1.375 false 0.49,2.094 0.802,2.292 0.313,0.198 10 false A1 0.563,1.292 0.813,1.49 0.25,0.198 10 false B 0.167,0.167 0.479,0.365 0.313,0.198 10 false *a
*a Front view of wire harness connector
(to 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
A1-1 (B) - Body ground Always 11 to 14 V



Result:
Proceed to
OK
NG



OK

2.CHECK TERMINAL VOLTAGE (POWER SOURCE OF STOP LIGHT SWITCH ASSEMBLY)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BATTERY)

2.CHECK TERMINAL VOLTAGE (POWER SOURCE OF STOP LIGHT SWITCH ASSEMBLY)
A312702C02
0.458,2.052 0.875,2.333 0.417,0.281 2.094,2.125 2.5,1.344 2.5,1.344 2.75,1.344 false 2.813,1.26 3.125,1.458 0.313,0.198 10 false B 0.167,0.167 0.479,0.365 0.313,0.198 10 false *a 0.583,2.094 0.896,2.292 0.313,0.198 10 false A1
*a Front view of wire harness connector
(to 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
A1-5 (B) - Body ground Ignition switch ON 11 to 14 V



Result:
Proceed to
OK
NG



OK

3.CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BODY GROUND)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - IG2 RELAY)

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
A1-3 (GND) - Body ground Always Below 1 Ω



Result:
Proceed to
OK
NG



OK

4.CHECK TERMINAL VOLTAGE (STP AND ST1- VOLTAGE)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

4.CHECK TERMINAL VOLTAGE (STP AND ST1- VOLTAGE)
a.

Disconnect the ECM connector.

A194116C16
4.083,1.635 4.427,1.854 0.344,0.219 5.594,2 5.646,2.469 false 5.521,1.99 5.323,2.469 false 2.979,1.969 3.208,2.135 0.229,0.167 10 false *b 1.229,1.969 1.438,2.167 0.208,0.198 10 false *a 4.198,0.385 4.427,0.698 0.229,0.313 10 false *c 5.573,2.49 6.177,2.667 0.604,0.177 10 false STP 4.135,1.656 4.594,1.99 0.458,0.333 10 false A56 5.156,2.49 5.677,2.667 0.521,0.177 10 false ST1-
*a Brake Pedal Depressed *b Brake Pedal Released
*c Front view of wire harness connector
(to ECM) 		- -



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
A56-35 (ST1-) - Body ground Brake pedal released 7.5 to 14 V
Brake pedal depressed Below 1.5 V
A56-36 (STP) - Body ground Brake pedal released Below 1.5 V
Brake pedal depressed 7.5 to 14 V



Result:
Proceed to
OK
NG



OK

REPLACE ECM

Click hereEngine / Hybrid System>2NZ-FE ENGINE CONTROL>ECM>REMOVAL


NG

5.CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - ECM)
5.CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - ECM)
a.

Disconnect the stop light switch assembly connector.


b.

Disconnect the ECM connector.


c.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:
Tester Connection Condition Specified Condition
A1-2 (L) - A56-36 (STP) Always Below 1 Ω
A1-4 (L) - A56-35 (ST1-) Always Below 1 Ω
A1-2 (L) or A56-36 (STP) - Body ground Always 10 kΩ or higher
A1-4 (L) or A56-35 (ST1-) - Body ground Always 10 kΩ or higher



Result:
Proceed to
OK
NG



OK

REPLACE STOP LIGHT SWITCH ASSEMBLY

Click hereVehicle Exterior>LIGHTING (EXT)>STOP LIGHT SWITCH>REMOVAL


NG

REPAIR OR REPLACE HARNESS OR CONNECTOR