P0286
Cylinder 9 Injector Circuit High
If your code reader dashboard displays the generic DTC error code P0286, your vehicle is currently experiencing an active failure related to "Cylinder 9 Injector Circuit High". Proper system troubleshooting is required to safely clear this warning.
Driver's Summary
Code P0286 means your vehicle detected a problem with the cylinder 9 injector circuit high system. You may notice misfire, rich exhaust smell, check engine light flashing, all of which are direct consequences of this malfunction. Given the high severity of this code, continuing to drive risks significant mechanical damage. Have it diagnosed immediately.
Symptoms
Misfire, rich exhaust smell, check engine light flashing
Common Causes
- Short to voltage in Cyl 9 circuit
- Internally shorted injector
- Damaged wiring harness
- PCM failure
How to Fix
- 1 Repair short to voltage
- 2 Replace Cyl 9 injector
- 3 Repair wiring harness
- 4 Reflash or replace PCM
Technical Explanation
To set P0286, the PCM samples the affected circuit multiple times per second, comparing live readings against manufacturer-programmed operating windows. Misfire rate is counted per cylinder over rolling windows and compared against two thresholds: a catalyst-damaging rate (triggers flashing MIL) and an emissions-exceeding rate (triggers solid MIL). The PCM logs which cylinder is misfiring based on crankshaft position at the time of each detected event. After two failed drive cycles, the code transitions from a pending to a confirmed DTC, and the PCM activates the MIL. Clearing the code without repairing the fault will result in re-illumination within one to two complete drive cycles.
Is It Safe to Drive?
An active P0286 code under high-severity conditions means the affected system is operating outside safe parameters. Continued driving — especially under load or at highway speeds — significantly increases the risk of secondary damage to components like internally shorted injector.
Mechanic's Pro Tip
Before replacing any component on P0286, spend 5 minutes inspecting the wiring harness and connector first — corrosion, chafed insulation, and backed-out pins cause the majority of these faults and cost nothing to fix. Use a multimeter to measure voltage drop across the connector pins under load; anything above 0.1V indicates excessive resistance that will cause intermittent failures even after replacing the sensor.
Related Fault Codes
Frequently Asked Questions
What does OBD2 code P0286 mean?
OBD2 code P0286 refers to Cylinder 9 Injector Circuit High. If your code reader dashboard displays the generic DTC error code P0286, your vehicle is currently experiencing an active failure related to "Cylinder 9 Injector Circuit High". Proper system troubleshooting is required to safely clear this warning.
What are the most common symptoms of DTC P0286?
Drivers experiencing code P0286 typically report: Misfire, rich exhaust smell, check engine light flashing.
Is it safe to drive with trouble code P0286 active?
An active P0286 code under high-severity conditions means the affected system is operating outside safe parameters. Continued driving — especially under load or at highway speeds — significantly increases the risk of secondary damage to components like internally shorted injector.
How much does it cost to fix code P0286?
The estimated repair cost for P0286 ranges from $150 to $500 USD. Injector: 200 - 500
Injector: 200 - 500
Need Professional Diagnostic Assistance?
Always verify sensor signals and wiring integrity with an OBD2 scanner before purchasing replacement parts.
Explore All Powertrain Codes →