Powertrain, generic (extended)

P245D EGR Cooler Bypass Control Circuit High (Bank 1)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

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.

Likely causes

Control software reporting a false actuator fault (known on some Ram diesels)
Control wire shorted to a battery or ignition feed
Actuator motor drawing excessive current (low-resistance winding, binding)

Symptoms

  • Malfunction indicator lamp on
  • Bypass actuator switched off by the controller and left in default position

Repair estimate

DifficultyMediumDIY possible
Parts and labour€0–700
Time0.3–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

egr cooler bypass valve b1

Related codes

P245AP245BP245CP2491P2457

References: gsi.ext.gm.com, static.nhtsa.gov, gsi.ext.gm.com.