Powertrain, generic (extended)

P2C2E Turbocharger/Supercharger Bypass Valve B Supply Voltage Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2C2E concerns the power stage of compressor bypass valve B, not its position signal. Such valves are moved by a small DC motor driven through an H-bridge, and the bridge reports when its own supply sags below a safe level. No manufacturer documents the B-side code publicly. GM's 2019 LT5 tables describe the equivalent for valve A (P2BBF): the motor driver flags low voltage in 80 of 100 checks spaced 12.5 ms apart, enabled at relay voltage of at least 11 V without cranking, Type A. NXP's MC33926 data sheet shows how a bridge of this kind disables its outputs under undervoltage and signals the fault. A weak battery feed, a poor module ground, a corroded relay or an internal driver fault are typical causes; the valve then remains in its last position.

Likely causes

Weak battery or voltage drop on the module feed
Poor ground or corroded relay contacts in the supply
Internal fault of the H-bridge driver

Symptoms

  • Check engine light
  • Valve no longer responds, boost reduced
  • Often accompanied by other low-voltage codes

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€40–1,200
Time0.5–3 h

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

Parts involved

turbo bypass valve bwiring harnessecm

Related codes

P2BBFP2C2FP00C0P00C1

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