P0ACC: Hybrid/EV Battery Temperature Sensor C Circuit Low

What it means

The ECM detects a circuit low fault on the hybrid/ev battery temperature sensor c circuit. Reading cannot be used reliably for control.

At a glance

• Usually lights the check-engine light
• The engine or gearbox may go into limp mode

How it works

Battery temperature sensor C reports the temperature at one location in the hybrid or EV battery pack through an electrical signal. This code sets when the sensor C signal is detected below the circuit's expected range, such as from a short to ground or a sensor fault.

Common causes

Most likely first.

1. Signal wire shorted to ground
2. Internal sensor short
3. Connector pins corroded - high contact resistance

Symptoms

• EV/hybrid system warning light on
• Reduced power output or limp mode
• Charging may fail or be slowed
• Reduced electric range

How to diagnose it

1. Record freeze-frame data and compare sensor C live data with the other battery temperature sensors to see whether its reading is abnormally low or fixed.
2. Inspect the sensor C connector and harness for chafing, corrosion, moisture, or contact with ground.
3. Using the wiring diagram, check whether the sensor C signal wire is shorted to ground.
4. Test sensor C and its circuit according to the manufacturer's specification, isolating the sensor from the harness as directed.
5. If the circuit and sensor pass, check for battery control module faults that could pull the input low.

Common fixes

• Clean and secure a corroded or loose sensor C connector.
• Repair a signal wire shorted to ground.
• Replace a sensor C that fails the manufacturer's test.
• Repair or replace the battery control module if diagnosis confirms an input fault.

Can I keep driving?

Avoid fast charging, hard acceleration, and heavy loads while the vehicle may be limiting battery use because sensor C's signal is low. Seek prompt diagnosis if power is reduced or the hybrid/EV warning appears; do not access high-voltage battery components yourself.