Powertrain, generic (extended)

P23E1 EGR C Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P23E1 covers the electrical drive of EGR valve C, a third exhaust gas recirculation actuator next to valves A and B. Which valve carries the letter C is up to the manufacturer; no carmaker documents P23E1 publicly. The code means the module has found the control circuit open or otherwise faulty. GM's 2018 diesel tables show how the A-side equivalent P0403 works: with the H-bridge driver off and the valve commanded away from closed, a load resistance above 200 kΩ in 96 of 120 samples sets the code as Type B, MIL after two trips. A similar check is plausible for valve C. CARB requires EGR components to be monitored for circuit faults. With this path disabled, NOx rises. Shorts are P23E3 and P23E4.

Likely causes

Unplugged or corroded connector at EGR valve C
Open motor winding or solenoid coil in valve C
Broken drive wire between engine module and valve C

Symptoms

  • Warning lamp with otherwise normal driving
  • Raised NOx at emissions testing

Repair estimate

DifficultyMediumDIY possible
Parts and labour€40–600
Time0.5–2.5 h

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

Parts involved

egr valve c

Related codes

P23E2P23E3P23E4P0403P045A

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