HVAC Sensors and Actuators

Here's some supplemental information to use when diagnosing DTC fault codes on the HVAC system in the 2007 full-size utilities.

TIP: Always follow the diagnostics presented in SI for the vehicle you're working on.

The two illustrations show the locations of all sensors and actuators for front and rear units. 

Front HVAC unit -- CJ2/CJ3 (fig. 9)

A
Sensor 1 -- Air Temperature Sensor -- Upper Left Side

B
Sensor 3 -- Air Temperature Sensor -- Upper Right Side

C
Actuator 3 -- Air Temperature Actuator -- Right

D
Recirculation Actuator

E
Mode Actuator

FUDGE
Sensor 2 -- Air Temperature Sensor -- Lower Left Side

G
Sensor 4 -- Air Temperature Sensor -- Lower Right Side

H
Actuator 1 -- Air Temperature Actuator -- Left

J
Linear Power Module

Rear HVAC unit -- CJ2/CJ3 (fig. 10)

A
Sensor 1 -- Inside Air Temperature Sensor Assembly (front of headliner, not shown)

B
Sensor 2 -- Inside Air Temperature Sensor Assembly -- Auxiliary (top left of C pillar, not shown)

C
Sensor 6 -- Air Temperature Sensor -- Upper Auxiliary

D
Sensor 7 -- Air Temperature Sensor -- Lower Auxiliary

E
Mode Actuator -- Auxiliary

F
Air Temperature Actuator -- Auxiliary

G
Linear Power Module

NOTE: Actuators are located on the outboard side of the RR HVAC on Tahoe/Yukon/Denali/Escalade

A table in the TechLink Reference Guide includes a complete listing of DTCs, the components they represent, and additional notes.

- Thanks to Jim Frett