P245A: EGR Cooler Bypass Control Circuit/Open (Bank 1)

The bypass lets cold-start EGR skip the cooler and is switched back to cooling once the engine is warm. P245A flags the bank 1 control circuit, usually as an open. GM's 2017 tables show both actuator types: on the Duramax with a DC-motor flap the controller sees a load resistance above 200 kOhm while the H-bridge is off and needs 160 failures in 200 samples, while the vacuum-switched version needs 24 of 30 samples with the flap commanded to cooling; both are Type B. Ford used P245A differently on its 2013 to 2015 6.7 L Power Stroke, as an intrusive check that fails when the gas temperature after the cooler moves by less than 3 °C per second after the flap switches; in 2023 that test carries P245B. Ford reflashed 2018 to 2019 Super Duty PCMs for P245A. Shorts are P245C and P245D, bank 2 is P248E.

Medium severity. Can I keep driving?You can normally drive in moderation, but get it repaired soon: if the valve is stuck open, the engine may idle very poorly.

Bank 1 is the side of the engine with cylinder 1. Inline engines only have this bank.

Symptoms

Malfunction indicator lamp on
EGR cooler bypass no longer switching; possible P2457 or P24A5 as follow-up

Most likely causes

Open wire or unplugged connector at the bypass actuator
Actuator motor or solenoid winding open
Control software needing an update (some Ford diesels)

What to check, in order

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

Check the connector and any vacuum hoses
Check the continuity of the wire between the component and the control module.
Use live data to compare the commanded opening with the actual opening
Clean the valve and passages if they are clogged with carbon
Test the actuator with the scanner
Replace the valve if it still does not follow the command after cleaning

Good to know

Repair difficulty: medium
It affects emissions.

What each character of P245A means

P: Powertrain: engine and transmission
2: Generic code: same on every make
4: Emissions
5A: Specific fault in that system

Frequently asked questions

Can I keep driving with code P245A?

You can normally drive in moderation, but get it repaired soon: if the valve is stuck open, the engine may idle very poorly.

What causes code P245A?

The most common causes are: open wire or unplugged connector at the bypass actuator; actuator motor or solenoid winding open; control software needing an update (some Ford diesels).

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.