Powertrain, generic (extended)

P23E2 EGR C Control Circuit Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P23E2 is raised when the drive circuit of EGR valve C is electrically intact but the valve does not respond to it as expected: commanded and measured position, or drive current and movement, drift apart. In GM's 2018 diesel calibration the A-side check P0404 compares setpoint and measured position of the high-pressure EGR valve and fails above a 10 % tracking error in 152 of 190 samples, with coolant at least 60 °C and outside air above −7 °C; it is a Type B code. Soot and lacquer, which over time stiffen EGR valves, are the usual reason, a worn gear train or a weak motor the next. No manufacturer documents P23E2 publicly; CARB asks that EGR control be checked for proper function. Circuit faults on valve C: P23E1, P23E3, P23E4.

Likely causes

Soot and lacquer making valve C sluggish
Worn gears or linkage in the valve C actuator
Actuator motor of valve C losing torque

Symptoms

  • Warning lamp after warm-up drives
  • Occasional hesitation when EGR is cut

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€100–800
Time0.5–3 h

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

Parts involved

egr valve c

Related codes

P23E1P23E5P23E6P0404P045B

References: gsi.ext.gm.com, law.cornell.edu, en.wikipedia.org.