Evaporator Temperature Sensor Signal Out of Range
The B2606 code indicates that the A/C control module (A/C Auto Amp. or ECM/BCM, depending on the model) has detected an evaporator temperature sensor (or intake air temperature sensor) signal that is outside the programmed calibration range. This means the signal voltage is either too high (open circuit) or too low (short to ground) to represent a valid physical temperature.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty A/C evaporator temperature sensor
- Open or short circuit in the sensor harness (signal or ground wire)
- Damaged, corroded, or disconnected sensor connector
- Internal failure of the A/C control module (A/C Auto Amp.)
- Refrigerant leak causing actual extreme temperatures outside normal range
3. Symptoms You Will Notice
- A/C system blows warm air or fails to cool properly
- A/C compressor may not engage or cycles erratically
- Check Engine Light or A/C warning light illuminated
4. Step-by-Step Diagnosis
Scan for B2606 and note any related codes
Visually inspect the evaporator temperature sensor connector and wiring for damage, corrosion, or loose connections
Measure sensor resistance and compare to manufacturer specifications; replace if out of range
Check for open or short circuits in the sensor circuit using a multimeter
If sensor and wiring are okay, test the A/C control module for proper operation
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, it is generally safe to drive, but the A/C may not work properly. Prolonged driving without A/C could be uncomfortable, and in some cases, the system may not defrost the windshield effectively.
How much does it cost to fix?▼
The repair cost typically ranges from $150 to $400, depending on the cause. Replacing the sensor is usually $50-$150 for parts and labor, while a control module replacement can be $200-$400.