ABS Warning Light Remains ON: Wiring Diagram

WARNING: This page is about a different car, the 2006 Lexus IS 350. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Wiring Diagram

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NOTE: When replacing the skid control ECU, perform zero point calibration (See CALIBRATION ).

CHECK CAN COMMUNICATION SYSTEM

Check if the CAN communication system DTC is output (See DIAGNOSIS SYSTEM ).

Result

CONDITION CHART

Condition	Proceed to
DTC is not output	A
DTC is output	B

B : INSPECT CAN COMMUNICATION SYSTEM

A : GO TO NEXT STEP

CHECK MULTIPLEX COMMUNICATION SYSTEM

Check if the multiplex communication system DTC is output (See DTC CHECK/CLEAR ).

Result

CONDITION CHART

Condition	Proceed to
DTC is not output	A
DTC is output	B

B : INSPECT MULTIPLEX COMMUNICATION SYSTEM

A : GO TO NEXT STEP

CHECK IF SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED
1. Check if the skid control ECU connector is securely connected.
  OK: The connector should be securely connected.
NG : CONNECT CONNECTOR TO ECU CORRECTLY

OK : GO TO NEXT STEP
CHECK BATTERY
1. Check the battery voltage.
  Standard voltage:
  
  11 to 14 V
NG : CHECK AND REPLACE CHARGING SYSTEM OR BATTERY

OK : GO TO NEXT STEP

INSPECT SKID CONTROL ECU (IG1 TERMINAL)

Disconnect the skid control ECU connector.
Turn the engine switch on (IG).

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

Standard voltage

TESTER CONNECTION AND SPECIFIED CONDITION CHART

Tester Connection	Condition	Specified Condition
J77-1 (IG1) - Body ground	Engine switch on (IG)	10 to 14 V

Fig 2: Inspecting Skid Control ECU (IG1 Terminal)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 CIRCUIT)

OK : GO TO NEXT STEP

INSPECT SKID CONTROL ECU (GND TERMINAL)

Turn the engine switch off.
Disconnect the skid control ECU connectors.

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

Standard resistance

TESTER CONNECTION AND SPECIFIED CONDITION CHART

Tester Connection	Condition	Specified Condition
J78-26 (GND1) - Body ground	Always	Below 1 Ω
J78-14 (GND2) - Body ground	Always	Below 1 Ω
A35-22 (GND3) - Body ground	Always	Below 1 Ω

Fig 3: Inspecting Skid Control ECU (GND Terminal)

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)

OK : GO TO NEXT STEP

INSPECT COMBINATION METER ASSEMBLY
1. Reconnect the skid control ECU connectors.
2. Perform Active Test of the combination meter (meter CPU) using the intelligent tester (See DATA LIST / ACTIVE TEST ).
  OK: The ABS warning light turns on or off in accordance with the intelligent tester.
  
  HINT:
  
  If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step before replacing the part (See PROBLEM SYMPTOMS TABLE ).
NG : REPLACE COMBINATION METER ASSEMBLY

OK : REPLACE SKID CONTROL ECU