Codes 17 & 18

This relay circuit supplies power to the TRAC motor relay. If the accumulator pressure drops, the ECU switches the motor relay ON and operates the TRAC motor.

CODES 17 & 18 CIRCUIT DESCRIPTION

Code	Diagnostic Code Detecting Condition	Trouble Area
17	Conditions [1] through [4] continue for 0.2seconds or more:	TRAC motor relay. Open or short in TRAC motor relay circuit. ECU.
"	[1] TRAC solenoid relay: ON	circuit. ECU.
"	[2] No open circuit in TRAC solenoid relay	"
"	[3] TRAC motor relay: ON	"
"	[4] Voltage of ABS & TRAC ECU terminal MTT: 0V	"
18	Conditions [1] and [2] continue for 2 seconds or more:	TRAC motor relay. +B short in TRAC motor relay circuit. ECU.
"	[1] TRAC motor relay: OFF [2] Voltage of ABS & TRAC ECU terminal MTT: Battery voltage.	"

NOTE: Fail Safe Function: If trouble occurs in the solenoid relay circuit, the ECU cuts off current to the solenoid relay and prohibits ABS control.

Fig 1: Codes 17 & 18 Wiring Schematic

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 2: Codes 17 & 18 TRAC Motor Relay Circuit Check (1 of 3)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 3: Codes 17 & 18 TRAC Motor Relay Circuit Check (2 of 3)

Fig 4: Codes 17 & 18 TRAC Motor Relay Circuit Check (3 of 3)