Powertrain, generic (extended)

P21EE Cylinder 10 Injector B Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P21EE is the low-circuit code for the B injector of cylinder 10, the last cylinder of a V10. In practice that points to a ten-cylinder engine with two injectors per cylinder, of which only Lamborghini's Huracán is documented: its V10 pairs a direct injector with a port injector at each cylinder and was presented as the first V10 to combine both. Lamborghini does not publish which set is B or whether it uses this code. With cylinders 1 to 5 on one bank and 6 to 10 on the other, cylinder 10 is on the second bank. A short to ground is the core fault; CARB lets a maker report a broken wire under the same code instead of a separate open code. Before replacing parts, read the open code P21D8 and the A injector low code P0288 as well. High fault: P21EF.

Likely causes

Cylinder 10 B injector wire grounded
Damaged or corroded injector connector on cylinder 10
Injector with internal ground fault
Engine control unit output defective

Symptoms

  • Check engine light on
  • Rough running or misfire on cylinder 10 (P0310)
  • Fuel trim deviation on the second bank

Repair estimate

DifficultyHardWorkshop job
Parts and labour€150–1,200
Time1–5 h

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

Parts involved

fuel injectorinjector wiringengine control module

Related codes

P21EFP21D8P0288P21ECP21F0P0310

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