P21DACylinder 12 Injector B Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P21DA closes the circuit/open series of the second injectors with cylinder 12. It requires a twelve-cylinder engine with two injectors per cylinder; no manufacturer documents this code publicly and no available source names such an engine using it. The fault type is the same as for its documented siblings: the control unit switches the injector and sees no current or an impedance far above normal. GM's LT5 injection module, for example, treats 200 kOhm or more as open and stores a Type A fault after 20 of 25 samples. CARB demands this kind of electrical monitoring for injectors. Directly after this code the series continues with the low and high faults P21DB and P21DC for cylinder 1; the A-side open code for cylinder 12 is P020C, the misfire code P0312.
- What you may notice
- Check engine light on
- Misfire on cylinder 12 (P0312)
- Likely causes
- LikelySecond injector of cylinder 12 with open coil
- PossibleWire or terminal fault in the injector harness
- RareOutput stage of the controlling module failed
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €150 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.