Battery Temperature Sensor Circuit Low Voltage
The P0516 code indicates that the Engine Control Module (ECM) has detected a voltage signal from the battery temperature sensor that is lower than the expected range. This sensor is typically located on or near the battery and measures electrolyte temperature to adjust charging voltage. A low voltage reading can result from a faulty sensor, damaged wiring, or poor electrical connections. The ECM may compensate by altering charging system behavior, potentially leading to overcharging or undercharging.
1. Most Common Causes
- Faulty battery temperature sensor (internal short circuit)
- Signal circuit wiring shorted to ground (chassis)
- Damaged, corroded, or pushed-back terminals in the sensor connector
- Internal PCM failure (rare, but possible in the 5V reference driver or ADC)
- Incorrectly installed battery or incompatible sensor with the vehicle
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Battery overcharging or undercharging
- Premature battery failure
- Electrical system irregularities
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the battery temperature sensor and its wiring for damage or corrosion.
Step 3: Test sensor resistance with a multimeter; compare to manufacturer specs (typically 2-10 kΩ at room temperature).
Step 4: Check for voltage at sensor connector (should be ~5V reference from ECM).
Step 5: If sensor and wiring are good, test ECM output or replace sensor.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe for short trips, but prolonged driving may cause battery damage due to improper charging. It's best to diagnose and repair promptly.
How much does it cost to fix?▼
Replacing the battery temperature sensor typically costs $50-$150 including parts and labor. If wiring repair is needed, costs may be higher.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.