Powertrain, generic (extended)

P21D1 Cylinder 3 Injector B Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P21D1 concerns the B injector of cylinder 3, which on Ford's 1.5 EcoBoost three-cylinder is the last one in the block. That engine combines port and direct fuel, and Ford names the port injectors B. Bulletin SSM 49996 for the 2021 Bronco Sport describes P21CF, P21D0 and P21D1 appearing together with transmission and other codes, in some cases with a no-crank condition, because the harness was damaged at the transmission cover; when all three B codes show at once, a shared wiring fault is far more likely than three bad injectors. Ford's summary checks the B circuits continuously above 11 V within 5 s. GM's LT5 V8 module flags an open low side once 20 of 25 samples fail. The direct injector of the cylinder is coded P0203.

Likely causes

Harness damage affecting several injectors at once (Ford Bronco Sport, transmission cover)
Open coil in the cylinder 3 port injector
Connector not latched or corroded

Symptoms

  • Check engine light on
  • Rough running or misfire on cylinder 3
  • With harness damage also transmission codes or no crank

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–600
Time0.5–3 h

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

Parts involved

fuel injectorinjector wiringengine control module

Related codes

P0203P21E0P21E1P21CFP21D0P0303

References: static.nhtsa.gov, fordservicecontent.com, en.wikipedia.org, gsi.ext.gm.com.