P245DEGR Cooler Bypass Control Circuit High (Bank 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P245D is the short-to-supply case of the bank 1 bypass circuit. For the Duramax with a DC-motor bypass, GM's 2017 tables watch the current through the H-bridge while it drives the flap: more than 8 A in 160 of 200 samples sets a Type B fault. On the vacuum-switched version the check looks at resistance to the supply side, and the 2014 tables describe high voltage while the driver is on. Ram issued a PCM software update in 2025 for 2024 heavy-duty pickups with the 6.7 L Cummins that set P245D, together with other air handling codes, to remove false actuator faults, so the software level should be checked before the harness is opened. In a genuine case a wire touching a battery feed or an actuator with a low-resistance winding is found. Open circuit is P245A, short to ground P245C, bank 2 is P2491.
- What you may notice
- Malfunction indicator lamp on
- Bypass actuator switched off by the controller and left in default position
- Likely causes
- PossibleControl software reporting a false actuator fault (known on some Ram diesels)
- PossibleControl wire shorted to a battery or ignition feed
- PossibleActuator motor drawing excessive current (low-resistance winding, binding)
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €0 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.