P2B59 code meaning
Engine Coolant Flow Control Valve Control Circuit/Open
Powertrain system Generic code P2Bxx codes Check engine light
What P2B59 means
P2B59 is the open-circuit check for the drive of the coolant flow control valve. In GM's 25OBDG04B (3.0 L Duramax) the driver reports a load resistance above 200 kΩ, meaning one of the motor wires is disconnected; 80 of 100 samples set a Type B fault. Hyundai and Kia also use the code on the 2.5-litre Theta III engines with an integrated thermal management module (ITM): bulletins 26-EM-009H (Sonata, Tucson) and Kia TSB ENG 264 (K5, Sorento, Sportage, 2024–2025) describe P2B59F0 caused by an ECU logic error and fix it with new software, noting no driveability effect. Otherwise check the connector, the harness and the valve motor. Shorts to ground and to supply are reported separately as P2B5A and P2B5B.
P2B59 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.3 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2B59
- MIL on, often without any noticeable driveability change
- Valve stays in its default position, slower warm-up possible
Common causes of P2B59
- Most likelyECU judgement logic on Hyundai/Kia 2.5 Theta III (software update 26-EM-009H / ENG 264)
- PossibleValve connector unplugged, loose or with a pushed-out terminal
- PossibleMotor wire broken in the harness or valve motor winding open
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Engine coolant flow control valveWiring harnessECM
What each part of P2B59 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| B | Area: hybrid propulsion. |
| 59 | The exact fault in that area. |
What to do next
- Note P2B59 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2B59
What does P2B59 mean?
P2B59 means "Engine Coolant Flow Control Valve Control Circuit/Open". P2B59 is the open-circuit check for the drive of the coolant flow control valve. It is a generic code, so it means the same on every make.
Is it safe to drive with P2B59?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2B59 fail an emissions test?
Yes, it can. P2B59 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2B59 to fix?
Difficulty: medium. A typical repair takes 0.3 to 4 hours of work. This is a job for a workshop.
Will P2B59 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.