P020D
Cylinder 4 Injection Timing
Fuel injection
Generic OBD-II
High
What it means
P020D means the ECM has detected that the fuel injection timing on cylinder 4 is not matching what it commands. Because fuel is being delivered at the wrong point in the cycle, the engine can run rough, stumble, start hard, or lose power — and on diesels may smoke or knock. It usually points to a faulty injector, a timing-circuit wiring fault, or a crank/cam signal error.
High
Can I keep driving? Drive with caution — off injection timing on cylinder 4 can cause rough running, hard starting, and power loss; extended driving risks further engine strain.
Common symptoms
What you'll notice
- Check-engine light on
- Rough running, misfire-like stumble, or vibration
- Hard starting or long cranking
- Reduced power; on diesels, possible smoke or knock
Common causes
Most likely first
- Faulty or worn cylinder 4 fuel injectorLikely
- Injection-timing / injector control circuit wiring damaged or shortedCommon
- Camshaft or crankshaft position sensor signal error affecting timingCommon
- Injection-pump or timing fault (diesel systems)Less often
- Faulty ECM/PCM (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and check for companion injector or crank/cam correlation codes to focus the diagnosis.
- Inspect the cylinder 4 injector connector and wiring for damage, corrosion, or a short.
- Test the injector's resistance and, where possible, its response with a scan tool.
- Verify the camshaft and crankshaft position sensor signals are correct.
- Replace the faulty injector or repair the timing circuit as indicated, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P020D?+
Only briefly. Incorrect injection timing on a cylinder causes rough running and power loss and can strain the engine. Have it repaired promptly.
Can I just clear P020D?+
It returns quickly if the injector or timing circuit is faulty. Fix the cause rather than only clearing the code.
Related codes
Often seen with P020D
Read & clear P020D yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX