B0429 on Chevrolet
Auxiliary Air Temperature Actuator Range/Performance
B0429 on Chevrolet vehicles indicates auxiliary air temperature actuator range/performance. Au7o has documented this code across 1 Chevrolet model — most commonly on Cruze. A body code used by General Motors (Chevrolet, GMC, Cadillac) for the auxiliary — typically rear — air temperature blend actuator; some references also render it as rear temperature control circuit out of range. The auxiliary HVAC actuators are 5-wire bi-directional motors with a built-in feedback potentiometer using a low reference, 5-volt reference, position signal, and two control circuits. As the actuator shaft rotates, the position signal varies between 0 and 5 volts, which the module converts to counts (1 volt equals 51 counts, so 0-255); B0429 sets when the reported position falls outside the expected range. The symptom is rear or auxiliary-zone air that will not change temperature, stays stuck hot or cold, or a clicking noise behind the trim. This is a comfort fault, not a drivability or safety issue. Typical repair costs on Chevrolet range from $120 to $450, depending on the specific model and root cause.
Common Causes of B0429
- •Failed auxiliary/rear air temperature actuator (stripped gears or a failed feedback potentiometer are common)
- •Actuator harness open or shorted
- •Poor electrical connection at the actuator — corroded or loose connector
- •Blend door binding or broken off its pivot
- •Failed HVAC control module
- •Actuator not recalibrated after battery disconnect or replacement
B0429 on Chevrolet by Model
Chevrolet Cruze(1 issue)
- HVAC Blend Door / Mode Actuator Gear Stripping - Clicking Dash and Split Temperature2011-2019
The plastic gears inside the HVAC air temperature and mode (defrost) actuators strip, so the door stops reaching its commanded position and the actuator motor hunts back and forth. The signature is a rapid clicking or ticking from behind the dash, usually when the temperature or mode is changed or right after startup, together with air that stays cold on one side while the other side blows hot, or airflow stuck on defrost. Owners often mistake it for a low refrigerant charge or a plugged heater core, but the temperature split between left and right vents points at the blend door.
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View B0429 across all makes →Frequently Asked Questions
What does B0429 mean on Chevrolet?▼
B0429 stands for "Auxiliary Air Temperature Actuator Range/Performance." A body code used by General Motors (Chevrolet, GMC, Cadillac) for the auxiliary — typically rear — air temperature blend actuator; some references also render it as rear temperature control circuit out of range. The auxiliary HVAC actuators are 5-wire bi-directional motors with a built-in feedback potentiometer using a low reference, 5-volt reference, position signal, and two control circuits. As the actuator shaft rotates, the position signal varies between 0 and 5 volts, which the module converts to counts (1 volt equals 51 counts, so 0-255); B0429 sets when the reported position falls outside the expected range. The symptom is rear or auxiliary-zone air that will not change temperature, stays stuck hot or cold, or a clicking noise behind the trim. This is a comfort fault, not a drivability or safety issue. On Chevrolet specifically, this code is documented across 1 model.
What causes B0429 on Chevrolet vehicles?▼
Common causes on Chevrolet: Failed auxiliary/rear air temperature actuator (stripped gears or a failed feedback potentiometer are common), Actuator harness open or shorted, Poor electrical connection at the actuator — corroded or loose connector, Blend door binding or broken off its pivot, Failed HVAC control module. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix B0429 on a Chevrolet?▼
Repair costs on Chevrolet range from $120 to $450, depending on the specific model and root cause.
Which Chevrolet models have B0429 documented?▼
Au7o has documented B0429 on 1 Chevrolet model: Cruze.