P0E9D: DC/DC Converter Current Sensor B Circuit Low

P0E9D reports that the signal of DC/DC converter current sensor B has dropped below its valid range. Porsche documents it for the Taycan of model years 2020 to 2024 as P0E9D00, current sensor 2 of the converter with a short to ground, logged by the HV power electronics on the front axle (A49), the rear axle (A50) or both. A red warning tells the driver to stop safely because of an electrical fault, yet once the ignition has been cycled the entry is no longer active. Porsche blames a diagnostic threshold for current monitoring that was set too low and reprograms both control units, using PIWIS Tester version 43.500.000 or newer. Outside that case a real ground short or a dead sensor supply is the likely cause. The high counterpart is P0E9E.

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.

Symptoms

Red warning to stop the vehicle safely
Fault no longer active after an ignition cycle
Drive power reduced or vehicle not ready to drive

Most likely causes

Current monitoring threshold set too low in the software
Sensor B signal shorted to ground
Sensor supply missing inside the power electronics

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
With the connector unplugged, check whether the signal wire is making contact with ground.
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

It can trigger limp mode.
It affects emissions.

What each character of P0E9D means

P: Powertrain: engine and transmission
0: Generic code: same on every make
E: Subsystem depends on the code range
9D: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0E9D?

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 P0E9D?

The most common causes are: current monitoring threshold set too low in the software; sensor B signal shorted to ground; sensor supply missing inside the power electronics.

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.