Powertrain, generic (extended)

P2BC0 Turbocharger/Supercharger Bypass Valve A Driver Current/Temperature Too High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2BC0 sets when the output stage that drives bypass valve A reports too much current or overheating. GM applies it to the electric recirculation valve of the LT5-powered 2019 Corvette ZR1: when the H-bridge raises its flag in 80 out of 100 checks spaced 12.5 ms apart, with relay voltage of 11 V or more and no cranking, a Type A fault with immediate MIL results. Integrated H-bridges protect themselves by regulating current, folding it back as the chip warms and finally shutting off – NXP gives a thermal limit of about 175–200 °C junction temperature for its MC33926. Excess current usually comes from a sticking or jammed valve, a shorted motor winding or a short between the motor leads. P2BBF is the low-supply case of the same driver, P00D7 an overheated valve itself. The valve stops responding and boost is reduced.

Likely causes

Sticking or jammed valve making the motor draw high current
Shorted winding in the valve actuator motor
Motor leads shorted to each other or to ground in the harness
Overheated or damaged H-bridge driver in the engine module

Symptoms

  • Check engine light on immediately
  • Reduced boost and less power
  • Compressor surge noise when lifting off

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€150–1,200
Time0.5–3 h

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

Parts involved

turbo bypass valve awiring harnessecm

Related codes

P2BBFP00D7P23AAP2261P2C2F

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