Injector Circuit Malfunction - Cylinder 5
P0205 indicates the PCM detected a malfunction in the fuel injector circuit for cylinder 5, meaning the injector is not operating correctly or there is an electrical fault in its wiring. This causes incomplete fuel delivery to that cylinder, resulting in misfires and poor engine performance.
What You Might Notice
- Engine misfire on cylinder 5
- Rough idle and rough running engine
- Poor acceleration and reduced power
- Check Engine Light (MIL) illuminated
- Possible fuel smell from exhaust
Most Common Causes
- 1
Faulty fuel injector
The injector for cylinder 5 is stuck open, stuck closed, or has internal electrical failure preventing proper fuel spray pattern.
- 2
Wiring harness open or corroded
The wiring connector or harness leading to the cylinder 5 injector has breaks, corrosion, or loose connections interrupting the electrical signal.
- 3
Wiring short to ground or power
The injector circuit wiring has a short circuit that prevents the PCM from properly controlling the injector pulse.
- 4
Faulty PCM or injector driver
The PCM power stage controlling the injector circuit or the PCM itself is defective and cannot command the injector to fire.
How to Diagnose It
- 1
Check Faulty fuel injector — The injector for cylinder 5 is stuck open, stuck closed, or has internal electrical failure preventing proper fuel spray pattern.
- 2
Check Wiring harness open or corroded — The wiring connector or harness leading to the cylinder 5 injector has breaks, corrosion, or loose connections interrupting the electrical signal.
- 3
Check Wiring short to ground or power — The injector circuit wiring has a short circuit that prevents the PCM from properly controlling the injector pulse.
- 4
Check Faulty PCM or injector driver — The PCM power stage controlling the injector circuit or the PCM itself is defective and cannot command the injector to fire.
How to Fix It
- 1
Replace cylinder 5 fuel injector
Remove and replace the fuel injector for cylinder 5 with a new or remanufactured unit. This is the most common fix for this code.
- 2
Inspect and repair injector wiring
Check the injector connector and wiring harness for corrosion, loose connections, or damage. Clean connections and repair or replace damaged wiring as needed.
- 3
Test PCM and injector driver circuit
Use a multimeter to test the injector circuit voltage and resistance. If the wiring is good, the PCM power stage controlling the injector may be faulty and require replacement.
- 4
Replace PCM if injector and wiring are good
If the injector, connector, and wiring harness test good but the code persists, the PCM power stage or entire PCM module must be replaced.
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