What Does B0337 Mean?
This diagnostic trouble code indicates that the Body Control Module (BCM) or climate control module has detected an abnormally low voltage or direct ground connection on the inside air temperature sensor circuit. The sensor, which monitors cabin temperature for automatic climate control systems, is reading a voltage below the normal operating range, typically indicating a short circuit to ground in the wiring harness, connector, or the sensor itself. This prevents the climate control system from accurately monitoring cabin temperature for proper HVAC operation.
Common Causes
40%
Damaged or chafed wiring harness causing direct short to ground between sensor and module
35%
Failed inside air temperature sensor with internal short circuit
15%
Corroded or moisture-damaged connector terminals creating ground path
10%
Faulty Body Control Module or climate control module with internal circuit damage
Diagnostic Steps
1
Step 1: Locate the inside air temperature sensor (typically near the HVAC unit, dashboard center, or behind instrument panel). Visually inspect the sensor, connector, and visible wiring for damage, corrosion, moisture intrusion, or chafed insulation against metal surfaces.
2
Step 2: Disconnect the inside air temperature sensor connector. Using a digital multimeter, measure resistance between the sensor signal terminal and ground. A thermistor-type sensor should read between 2,000-10,000 ohms at room temperature (consult manufacturer specs). A reading of 0 ohms or near-zero confirms failed sensor.
3
Step 3: With sensor disconnected, measure resistance between the sensor signal wire terminal at the harness connector and known good chassis ground. Reading should be infinite (OL). If continuity or low resistance is present, trace and repair short to ground in wiring harness between sensor and control module.
4
Step 4: If wiring tests good, reconnect sensor and monitor live data parameters while gently wiggling harness and connectors. If fault becomes intermittent, repair intermittent connection. If sensor and wiring test good, test control module signal voltage with sensor disconnected (typically 5V reference), and suspect module if reference voltage is absent or shorted.
5
Step 5: After repair, clear codes, perform climate control system relearn or calibration procedure if required by manufacturer, cycle ignition, operate HVAC system through all modes, and verify code does not return and cabin temperature reading is accurate.
Estimated Repair Cost
$100 - $450
Parts + labor, varies by vehicle and location
This diagnostic trouble code indicates that the Body Control Module (BCM) or climate control module has detected an abnormally low voltage or direct ground connection on the inside air temperature sensor circuit. The sensor, which monitors cabin temperature for automatic climate control systems, is ...
The most common cause of B0337 (Inside Air Temp Sensor Short to GND) is: Damaged or chafed wiring harness causing direct short to ground between sensor and module
Typical repair costs for B0337 range from $100 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This code does not affect vehicle safety or drivability and the vehicle can be operated normally. The automatic climate control system may not function optimally and may default to manual mode or fixed blower speeds until repaired.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B0337 to identify the root cause.
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Quick Info
Category
Body
System
Climate Control / HVAC System
Difficulty
Type
Generic (SAE)
Recommended Tools
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