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Home >> Lexus >> 1992 >> LS 400 >> Repair and Diagnosis >> Brakes >> Traction Control >> Traction Control System >> Diagnostic Charts >> Code 13, 14 TRAC Throttle Relay Circuit >> Circuit Description
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Circuit Description

This relay circuit supplies power to the sub-throttle motor through the ECU. When the ignition switch is turned on, the relay goes on. If trouble occurs in this relay circuit, the ECU cuts off current to the TRAC throttle relay and stops the traction control (Fail-safe mode).

CODE 13 & 14 DIAGNOSTIC

Code No. Diagnosis Trouble Area
13 When the ECU is sending an ON signal to the TRAC throttle relay, terminal BM of the ECU is 0V. TRAC throttle relay. (Remains OFF) Harness or connector between TRAC throttle relay and ECU. (open or short in TTR, R-, BM harness) Harness or connector between battery and TRAC throttle relay. (open or short) ECU
14 When the ECU is not sending an ON signal to the TRAC throttle relay, terminal BM of the ECU is battery voltage. TRAC throttle relay. (Remains ON) Harness or connector between TRAC throttle relay and ECU. (+B short in TTR, BM harness) ECU