Circuit Description

WARNING: This page is about a different car, the 2003 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.

This sensor detects the position of the air mix damper and sends the appropriate signals to the A/C amplifier.

The position sensor is built into the air mix damper control servomotor assembly.

Fig 1: Damper Opening Angle - TP Terminal Voltage Graph

DTC B1431 TROUBLE DETECTION REFERENCE

DTC No.	Detection Item	Trouble Area
B1431	Short to ground or power source circuit in air mix damper position sensor circuit.	Air mix damper position sensor. Harness or connector between air mix damper control servomotor assembly and A/C amplifier. A/C amplifier.