BAT/Brakes, ABS & TRAC Systems — Dtc 53 ECM Communication Circuit Malfunction, page 156

BR–156
BRAKE SYSTEM – TRACTION CONTROL SYSTEM (TRAC)

DTC 53 ECM Communication Circuit Malfunction

CIRCUIT DESCRIPTION
This circuit is used to send TRAC control information from the TRAC ECU to the ECM (TRC+, TRC–), and engine control information from the ECM to the TRAC ECU (EFI+, EFI–).

DTC No. | Diagnostic Trouble Code Detecting Condition | Trouble area

53 | Either of the following (1) or (2) continues for 5 sec.:
(1) A signal is received from the ECM indicating trouble in the TRC+ or TRC– circuit.
(2) No EFI ± data is received from the ECM when the engine speed is 500 RPM or more, or the vehicle speed is 60 km/h (37 mph) or more. | Open or short in TRC+ or TRC– circuit
Open or short in EFI+ or EFI– circuit
ECM
TRAC ECU

WIRING DIAGRAM

ECM
5 V
EFI+ 27    B    3 EFI+
E10              T10
EFI– 26    W    8 EFI–
E10              T10
TRC+ 14    O    2 TRC+
E10              T10          5 V
TRC– 13   W-R   9 TRC–
E10              T10

TRAC ECU

RO7235

INSPECTION PROCEDURE

HINT: When the TRAC indicator light is ON, there is a problem in the EFI ± circuit, and when the TRAC indicator light is OFF, there is a problem in the TRC ± circuit.

1  Check for open and short n harness and connector between terminals EFI+, EFI–, TRAC+ and TRC– of ECU and ECM (See page IN–30).

OK                    NG    Repair or replace harness or connector.

Check and replace ECM or TRAC ECU.