Tech Tip: Toyota Highlander’s Heater Goes from Hot to Cold on its Own – UnderhoodService

Tech Tip: Toyota Highlander’s Heater Goes from Hot to Cold on its Own

A loose control knob potentiometer could cause erratic behavior on a Highlander climate control system.

Vehicle Applications: 2002 Highlander 3.0L;  2003-’04 Highlander 2.4L; 2004-’06 Highlander 3.3L

Customer Concern: Intermittent heater operation; the heater will go from hot to cold on its own.

Potential Causes: Loose control knob potentiometer. A loose ­control knob nut allowed the ­ribbon to be stretched, causing a poor connection.

Tests/Procedures:
1. Inspect the temperature ­control knob for a loose mounting nut and damaged wire ribbon.

2. Inspect the wire ribbon attached to the temperature control knob to see if it has come loose.

Tech Tips: Some technicians have been able to repair the damaged wire ribbon and reassemble the control panel to avoid complete control panel replacement.

Courtesy of Identifix.

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