Home › Fault codes › P2B6400

P2B6400 — Additional coolant pump (P5) – temperature too high

Additional coolant pump (P5) – temperature too high. The Taycan, 911 (992), Panamera (971), Panamera (972) and Cayenne report this code; below is which control unit sets it on each model and how to read and clear it.

Which models and control units set P2B6400

Porsche Taycan

Porsche 911 (992)

Porsche Panamera (971, 2017–2023)

Porsche Panamera (972, 2024–)

Porsche Cayenne (9YA)

How to read and clear P2B6400

  1. Plug a standard ENET (Ethernet-to-OBD) cable into your Porsche's OBD port and your Mac or Windows PC.
  2. Open STEUER14, pick your car and run a fault scan: every control unit is read, and P2B6400 shows with its status, its full description and the freeze frame when the unit stores one.
  3. Fix the cause first, then clear the fault memory and scan again to check it stays away. Reading and clearing fault codes is free on every control unit.

More about fault memory in the manual →

Download STEUER14 — free fault reading

Other codes of the Thermal Management

P2B2D00Temperature sensor for medium-temperature circuit (TW4) – short circuit to ground
P2B2E00Temperature sensor for medium-temperature circuit (TW4) – short circuit to B+
P2B2F00Right radiator fan (RF1) – performance too low
P2B3000Right radiator fan (RF1) – blocked
P2B3100Left radiator fan (RF3) – performance too low
P2B3200Left radiator fan (RF3) – blocked
P2B6500Additional coolant pump (P5) – dry run
P2B8600Coolant pump – dry run
P2B9E00Coolant pump – temperature too high
P2C6600Coolant pump (P1) – sluggish
P2C6800Coolant pump (P1) – blocked
P2C7200Medium-temperature circuit for drive, rear – cooling power too low

All 636 codes of this control unit →

Fault names come from the manufacturer's diagnostic data. STEUER14 is independent and not affiliated with Porsche AG. A code tells you what a control unit detected, not always which part failed — check wiring, supply voltage and related codes before replacing parts. STEUER14 shows each fault's full description, status and freeze frame on the car.