Cylinder 12 Injector Circuit High
The P0295 code means the vehicle's onboard diagnostic system has detected: Cylinder 12 Injector Circuit High. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $200 - $800 (parts and labor)
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Common Symptoms
- Engine misfire on cylinder 12
- Rough idle and vibration
- Check Engine Light illuminated
- Dead cylinder 12
- Poor fuel economy
Probable Causes (Ranked by Likelihood)
- Open circuit in cylinder 12 injector wiring Very High
- Faulty cylinder 12 fuel injector (open coil) High
- Disconnected or corroded injector connector High
- Broken ground wire to injector Moderate
- PCM injector driver circuit failure Low
Frequently Asked Questions
Can I drive with code P0271?
You can drive short distances. Cylinder 12 will not fire, causing noticeable vibration and power loss. Repair promptly to protect the catalytic converter.
What is the most common cause of P0271?
The most common cause is an open circuit, either from a burnt-out injector coil or a broken wire. Corroded connectors are also frequent culprits, especially in areas with road salt.
How do I test an injector coil?
Set a multimeter to the ohms setting and measure across the two injector terminals. A good injector typically reads 11-18 ohms. An open reading (OL) means the coil is burnt out.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Measure cylinder 12 injector resistance -- an open reading (OL) confirms a burnt-out coil
-
Check for 12V power at the injector connector with key on
-
Test for PCM ground pulse at the connector using a noid light during cranking
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Inspect the connector for pushed-back pins, corrosion, or water intrusion
-
Replace injector if coil is open; repair wiring if a break is found in the circuit
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Commonly Affected Vehicles
- 2010-2020 BMW 760Li (6.6T V12)
- 2012-2019 Mercedes-Benz S600 (6.0L V12)
- 2008-2018 Rolls-Royce Phantom (6.75L V12)
- 2011-2020 Ferrari GTC4Lusso (6.3L V12)
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