P21D1 code meaning
Cylinder 3 Injector B Circuit/Open
Powertrain system Generic code P21xx codes Check engine light
What P21D1 means
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.
P21D1 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P21D1
- Check engine light on
- Rough running or misfire on cylinder 3
- With harness damage also transmission codes or no crank
Common causes of P21D1
- Most likelyHarness damage affecting several injectors at once (Ford Bronco Sport, transmission cover)
- PossibleOpen coil in the cylinder 3 port injector
- Less likelyConnector not latched or corroded
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Fuel injectorInjector wiringEngine control module
What each part of P21D1 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 1 | Area: fuel and air metering. |
| D1 | The exact fault in that area. |
What to do next
- Note P21D1 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P21D1
What does P21D1 mean?
P21D1 means "Cylinder 3 Injector B Circuit/Open". P21D1 concerns the B injector of cylinder 3, which on Ford's 1.5 EcoBoost three-cylinder is the last one in the block. It is a generic code, so it means the same on every make.
Is it safe to drive with P21D1?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P21D1 fail an emissions test?
Yes, it can. P21D1 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P21D1 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P21D1 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.