Dtc P1520 Stop Light Switch Circuit Malfunction
DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
CHECK STOP LIGHT SWITCH ASSEMBLY (TERMINAL VOLTAGE)
CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BODY
GROUND)
CHECK ECM (STP, ST1- VOLTAGE)
CHECK HARNESS AND CONNECTOR
DTC P1520 Stop Light Switch Circuit Malfunction |
DESCRIPTION
In this system, the signal of the stop light switch is used to judge whether the stop light system is abnormal or not.The stop light switch has a duplex system (signals STP and ST1-) to recognize the abnormality when the signals of depressing and releasing the brake pedal are detected simultaneously.- HINT:
- The normal condition is shown in the table below.
Signal
| Brake Pedal Released
| In Transition
| Brake Pedal Depressed
|
STP
| Off
| On
| On
|
ST1-
| On
| On
| Off
|
DTC No.
| DTC Detection Condition
| Trouble Area
|
P1520
| Conditions (a), (b) and (c) continue for 0.5 seconds or more(1 trip detection logic):
(a) Ignition switch is ON.
(b) Brake pedal is released.
(c) STP signal is off when ST1- signal is off.
| - Open or short in stop light switch signal circuit
- Stop light switch
- ECM
|
WIRING DIAGRAM
INSPECTION PROCEDURE
- NOTICE:
- Inspect the fuses for circuits related to this system before performing the following 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, and other data from the time the malfunction occurred.
| 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
|
A85-1 (B) - Body ground
| Always
| 11 to 14 V
|
A85-5 (B) - Body ground
| Ignition switch ON
| 11 to 14 V
|
*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 - INTEGRATION RELAY, BATTERY) |
|
|
| 2.CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BODY
GROUND) |
Disconnect the stop light switch assembly connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection
| Condition
| Specified Condition
|
A85-3 (GND) - Body ground
| Always
| Below 1 Ω
|
Reconnect the stop light switch assembly connector.
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
| 3.CHECK ECM (STP, ST1- VOLTAGE) |
Turn the ignition switch to ON.
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
Tester Connection
| Brake Pedal Condition
| Specified Condition
|
G182-9 (STP) - C161-5 (E1)
| Depressed
| 11 to 14 V
|
Released
| Below 1.5 V
|
G182-10 (ST1-) - C161-5 (E1)
| Depressed
| Below 1.5 V
|
Released
| 11 to 14 V
|
Text in Illustration*a
| Brake pedal depressed
|
*b
| Brake pedal released
|
*c
| Component with harness connected
(ECM)
|
| 4.CHECK HARNESS AND CONNECTOR |
Disconnect the stop light switch assembly connector.
Disconnect the ECM connectors.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection
| Condition
| Specified Condition
|
A85-2 - G182-9 (STP)
| Always
| Below 1 Ω
|
A85-4 - G182-10 (ST1-)
| Always
| Below 1 Ω
|
A85-2 or G182-9 (STP) - Body ground
| Always
| 10 kΩ or higher
|
A85-4 or G182-10 (ST1-) - Body ground
| Always
| 10 kΩ or higher
|
Reconnect the stop light switch assembly connector.
Reconnect the ECM connector.
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
