C1503

DTC C1503 TCS/ESC SWITCH ERROR

DESCRIPTION
The TCS (ESC) OFF switch is for ON/OFF of TCS (ESC) function.
When the TCS (ESC) OFF switch is pushed, the TCS (ESC) system stops and the TCS (ESC) OFF lamp is ON.

DTC Detecting Condition:

FAIL-SAFE FUNCTION
The TCS/ESC function is inhibited, while the ABS and EBD controls allowed.
The TCS/ESC warning lamp is ON, but the ABS and EBD warning lamps OFF.

INSPECTION PROCEDURE
1. CHECK TCS (ESC) OFF SWITCH.
1. Remove the TCS (ESC) OFF switch from the panel of the driver's side crashpad.







2. Check for the continuity between the TCS (ESC) OFF switch terminals, when the TCS (ESC) OFF switch is ON.

Is there continuity between terminals 3 and 4 of the TCS (ESC) switch connector?

NO - Replace with a new TCS (ESC) OFF switch.

YES - Check short in circuit of TCS/ESC Switch.

2. CHECK SHORT IN CIRCUIT OF TCS/ESC SWITCH
1. Remove the TCS (ESC) OFF switch from the panel of the driver's side crashpad.
2. After the ignition switch is ON, measure the voltage between terminal 3 of the TCS (ESC) OFF switch connector and the body ground.

Specification: Battery positive (B+)

Is the voltage within the specification?

NO
1. Check and replace fuse (10 A).
2. Check and repair harness and connector.

YES - Check open/short in circuit between TCS (ESC) OFF switch and the HECU.

3. CHECK OPEN/SHORT IN CIRCUIT BETWEEN TCS (ESC) OFF SWITCH AND THE HECU
Check an open or short in the circuit between terminal 3 of TCS (ESC) OFF switch connector and terminal 14 (ESC:27) of the HECU connector.
Is the circuit normal?

NO - Check and repair the circuit between the switch and the HECU.

YES - After clearing the DTC and driving the vehicle at 40 km/h speed or more, if the TCS (ESC) lamp is ON and the same DTC shows again, replace the HECU and recheck.