Powertrain, generic · Hybrid propulsion

P0CD4 Charge Port Door A Unlock Control Circuit High

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P0CD4 is the high-level variant of the charge flap A unlock output fault. The control line reads high when the driver should be pulling it low or holding it off, as happens with a short to a 12 V wire, and on many low-side drivers also with an open actuator or broken wire. A flap actuator that is powered all the time may overheat, while an open one simply never releases. No manufacturer documents this code publicly; GM's Volt tables cover short to battery and open circuit within P0CD1. A Tesla patent describes the same principle, in which a controller closes a switch to supply the flap release actuator. CARB 13 CCR 1968.2 (e)(15) explains why comfort outputs like this rarely receive split low and high codes. Siblings: P0CD3 for low, P0CD2 for the movement check.

Likely causes

Actuator control wire shorted to a 12 V feed
Open actuator winding or broken wire
Output driver in the control module damaged

Symptoms

  • Charge flap does not unlock or unlocks unexpectedly
  • Actuator may become hot from continuous current

Repair estimate

DifficultyMediumDIY possible
Parts and labour€80–500
Time0.5–2.5 h

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

Parts involved

charge port door a unlock actuatorwiring harnesshybrid control module

Related codes

P0CD1P0CD2P0CD3P2EA0

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