P2CA9: DC/DC Converter Temperature Sensor F Circuit

The ECM detects a circuit fault on the dc/dc converter temperature sensor f circuit. Reading cannot be used reliably for control.

High severity. Can I keep driving?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.

Most likely causes

Sensor failed
Wiring or connector fault

What to check, in order

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

Read the codes with a hybrid-compatible scanner and write down the freeze frame data
Make sure the battery cooling air intake is clean
Check the 12 V auxiliary battery, which can also trigger warnings
Leave any high-voltage measurements to a specialized repair shop

Good to know

Repair difficulty: medium
It can trigger limp mode.

What each character of P2CA9 means

P: Powertrain: engine and transmission
2: Generic code: same on every make
C: Subsystem depends on the code range
A9: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2CA9?

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 P2CA9?

The most common causes are: sensor failed; wiring or connector fault.

Related codes

Sources

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.