P0C71: Hybrid/EV Battery Temperature Sensor D/E Correlation

P0C71 checks whether battery temperature sensors D and E agree with each other. Both sit in the same pack, so after a long soak they should report almost the same value; a lasting gap means one of them reads wrong although its circuit looks healthy. No manufacturer documents P0C71 publicly. GM and Mitsubishi run this plausibility test against the pack average instead and log the single sensor: on the eAssist cars (13OBDG05C) GM flags sensor 4 (P0AE9) or sensor 5 (P0BC3) beyond 8.55 °C after more than 21,600 s off, Type B, while the 2022 Outlander PHEV tolerates 13 °C after one hour. P0C70 covers the C/D pair and P0C72 the E/F pair; open or shorted sensors set their own circuit codes.

Symptoms

• Hybrid or EV system warning lamp
• Reduced battery charge and discharge power
• Battery cooling running more often than usual

Most likely causes

• Thermistor D or E drifted while staying inside its electrical range
• Sensor no longer pressed against its cell or module
• Genuine temperature difference from uneven cooling or a weak cell group
• Battery management software with an overly tight comparison

What to check, in order

Start with the simplest. You can tick off each step.

1. Read the codes with a hybrid-compatible scanner and write down the freeze frame data
2. Compare both signals at the same time in live data and check any recent installation work.
3. Make sure the battery cooling air intake is clean
4. Check the 12 V auxiliary battery, which can also trigger warnings
5. Leave any high-voltage measurements to a specialized repair shop

Good to know

• It can trigger limp mode.
• It affects emissions.

What each character of P0C71 means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• C: Subsystem depends on the code range
• 71: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0C71?

If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

What causes code P0C71?

The most common causes are: thermistor D or E drifted while staying inside its electrical range; sensor no longer pressed against its cell or module; genuine temperature difference from uneven cooling or a weak cell group.

Related codes

• P0C70Hybrid/EV Battery Temperature Sensor C/D Correlation
• P0C72Hybrid/EV Battery Temperature Sensor E/F Correlation
• P0AE9Hybrid/EV Battery Temperature Sensor D Circuit Range/Performance
• P0BC3Hybrid/EV Battery Temperature Sensor E Circuit Range/Performance

Sources

• gsi.ext.gm.com: 13OBDG05C Hybrid Diagnostics
• static.nhtsa.gov: MC 10155116 9999
• mitsubishitechinfo.com: M15494077A026000USA
• law.cornell.edu: 13 CCR 1968.2

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.