Powertrain, generic (extended)

P248E EGR Cooler Bypass Control Circuit/Open (Bank 2)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P248E is the bank 2 counterpart of P245A: the engine controller sees no proper load on the output that drives the EGR cooler bypass of the second cylinder bank, most often because the circuit is open. Only engines with a separate EGR path per bank can set it, which in practice means V engines with two coolers. No manufacturer documents this code publicly; the published diesel tables we checked only list bank 1. For comparison, GM's 2017 Duramax tables flag the bank 1 DC-motor flap when the load resistance with the H-bridge switched off exceeds 200 kOhm, rated Type B. CARB requires such actuators to be checked as comprehensive components. With the flap unpowered, warm-up or cooling of the recirculated gas is no longer controlled on that bank.

Likely causes

Unplugged connector or broken wire at the bank 2 bypass actuator
Open motor or solenoid winding in the bank 2 actuator
Faulty output stage in the engine control module

Symptoms

  • Check engine light on
  • Longer warm-up or higher NOx on one bank because the bypass stays put

Repair estimate

DifficultyMediumDIY possible
Parts and labour€30–700
Time0.5–3 h

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

Parts involved

egr cooler bypass valve b2

Related codes

P245AP248FP2490P2491P24A6

References: law.cornell.edu, gsi.ext.gm.com.