P0273
Fix within a few daysCylinder 5 Fuel Injector Circuit Low
Code P0273 means Cylinder 5 Injector Circuit Low. Common causes: Faulty fuel injector (70%), wiring issue (25%). Drivability: Yes, for short trips only. Repair cost: $50-$250 DIY, $200-$650 professional.
Can I Drive With P0273?
Yes, for short trips only
Essential trips under 10 miles, avoid highways and heavy acceleration
Stop driving immediately if: Flashing Check Engine Light, significant power loss, loud knocking noises, strong rotten egg smell from exhaust.
Symptoms of P0273
- 1Check Engine Light is on
- 2Engine misfire or rough idle
- 3Reduced engine power or acceleration
- 4Engine hesitation or stumbling
- 5Poor fuel economy
- 6Strong fuel smell from the exhaust
Common Causes of P0273
Parts most likely causing this code, ranked by probability
An internal electrical fault or mechanical failure within the injector itself causes the circuit to draw too little current or fail to open/close properly.
70% of P0273 cases are fixed by replacing this part
Damaged, corroded, or loose wiring or a faulty connector to the cylinder 5 fuel injector can interrupt the electrical signal, causing a 'low' circuit reading.
25% of P0273 cases are fixed by repairing this wiring
A rare internal fault within the PCM's driver circuit for cylinder 5 can prevent it from properly controlling the fuel injector.
5% of P0273 cases are fixed by replacing this part
Check These First (Before Buying Parts)
- Visually inspect the electrical connector and wiring for the cylinder 5 fuel injector for any obvious damage, fraying, or corrosion.
- Listen to the cylinder 5 fuel injector with a stethoscope to confirm it is clicking. Compare its sound to other working injectors.
How to Diagnose P0273
- 1Visually inspect the wiring harness and electrical connector for the cylinder 5 fuel injector for any signs of damage, corrosion, or loose connections.
- 2With the engine running, use a mechanic's stethoscope or a long screwdriver to listen for a distinct clicking sound from the cylinder 5 fuel injector. Compare its sound to other injectors.
- 3Using a multimeter, test the electrical resistance of the cylinder 5 fuel injector across its terminals. Compare this reading to manufacturer specifications and the resistance of other injectors.
- 4Disconnect the cylinder 5 fuel injector and check for continuity between the injector harness connector and the PCM connector. Also, check for any shorts to ground or power in the wiring.
- 5If the injector resistance is out of specification or it is not clicking, swap the cylinder 5 fuel injector with a known good injector from another cylinder. Clear the code and see if the P0273 code or misfire follows the injector to the new cylinder.
P0273 on Popular Vehicles
Ford F-150
2011-2024Ford F-150s, particularly those with EcoBoost engines, are known to have fuel injector failures that can trigger P0273. Carbon buildup on direct injection injectors can also contribute to issues.
75% fixed by replacing the fuel injector
Chevrolet Silverado
2007-2024Silverado trucks can experience P0273 due to aging fuel injectors or wiring harness issues, especially in high-mileage vehicles. Corrosion in connectors is a common culprit.
65% fixed by replacing the fuel injector, 20% by wiring repair
Honda Accord
2003-2024While less common than on trucks, P0273 on a Honda Accord typically indicates a failing fuel injector or a compromised wiring connection to cylinder 5, often due to age or environmental factors.
70% fixed by replacing the fuel injector
Frequently Asked Questions
What does P0273 mean?
P0273 indicates that the Powertrain Control Module (PCM) has detected an electrical circuit problem with the fuel injector for cylinder 5. The circuit is drawing less current than expected, suggesting an open circuit, a short, or a faulty injector.
Can I drive with P0273?
Yes, for short trips only. You can drive your vehicle for essential, short distances, but you must address this code quickly. Prolonged driving with a misfire can cause significant damage to your catalytic converter and potentially other engine components.
Will P0273 clear itself?
No, P0273 will not clear itself. The underlying electrical or mechanical fault causing the circuit low condition must be repaired. After the repair, you will need to clear the code with an OBD-II scanner, or it will eventually clear after several drive cycles if the issue is resolved.
How do I fix P0273 myself?
Start by inspecting the wiring and connector for cylinder 5. If they look good, test the injector's resistance with a multimeter. If the resistance is off, or if the injector isn't clicking, replacing the cylinder 5 fuel injector is the most common fix. If the problem persists, you'll need to check the wiring for continuity back to the PCM.
How much does it cost to fix P0273?
A DIY fix for P0273 typically costs $50-$250, primarily for a new fuel injector and possibly O-rings. Professional repair at a shop will cost $200-$650, including parts and 1-3 hours of labor.
P0273 keeps coming back - why?
If P0273 keeps returning, it indicates the initial repair did not address the root cause. Common reasons include a faulty wiring harness that was not fully repaired, a new injector that is also faulty, or a rare PCM issue. Ensure thorough electrical testing of the circuit and consider swapping the injector to confirm it's not the new part.
Will P0273 fail emissions/smog test?
Yes, P0273 will cause your vehicle to fail an emissions or smog test. A check engine light is an automatic failure in most jurisdictions, and a misfiring cylinder leads to increased emissions.
What's the difference between P0273 and P0305?
P0273 specifically indicates an electrical circuit problem with the cylinder 5 fuel injector. P0305, on the other hand, means a general misfire has been detected in cylinder 5. P0273 is a specific cause that will often lead to a P0305 code, but a P0305 can be caused by other issues like a bad spark plug or ignition coil.
P0273 on Ford F-150?
On Ford F-150s, especially EcoBoost models, P0273 often points directly to a faulty fuel injector for cylinder 5. These engines can sometimes experience injector issues, including carbon buildup affecting spray patterns or electrical failures. Thorough diagnosis of the injector and its wiring is critical.
Questions to Ask Your Mechanic
Did you test the resistance of the cylinder 5 fuel injector and compare it to specifications?
Good answer: Yes, I measured the resistance at [X ohms], and the specification is [Y ohms]. It's either open, shorted, or out of spec.
Did you check the wiring harness for cylinder 5 for continuity and shorts to ground or power?
Good answer: Yes, I performed a full circuit test from the injector connector back to the PCM and found no opens or shorts.
Repair Cost Estimate
DIY Repair
Parts only
$50-$250
Shop Repair
Parts + labor
$200-$650
Save $150-$400 by doing it yourself
Difficulty
intermediate
Time
1-3 hours
Intermediate - Requires basic electrical testing with a multimeter and careful handling of fuel system components. Access to the injector can vary in difficulty depending on the engine.
Cost of Waiting
Ignoring P0273 and the resulting misfire will send unburned fuel into your exhaust system. This rapidly overheats and destroys your catalytic converter, turning a $50-$200 fuel injector job into a $800-$2,500 converter replacement. Prolonged misfires can also wash down cylinder walls, leading to premature engine wear.
While You're In There...
These seals are removed and often damaged during injector replacement. Replacing them prevents fuel leaks and ensures a proper seal.
A misfiring injector can foul the spark plug. Replacing it ensures optimal combustion once the injector is fixed and prevents a repeat misfire.
Tools You'll Need
- OBD-II scanner
- Multimeter
- Basic hand tools (sockets, wrenches)
- Fuel injector puller (for some direct injection engines)
- Stethoscope (or long screwdriver)
P0273 is a common fuel system code. Most repairs involve replacing a single fuel injector, which is a straightforward job for an intermediate DIYer. Your engine will run smoothly again once fixed.
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Your Next Steps
Step 1: Visually inspect the wiring and connector for cylinder 5. Look for any cuts, fraying, or corrosion. Ensure the connector is fully seated.
Step 2: Use a multimeter to test the resistance of the cylinder 5 fuel injector. If it's outside the manufacturer's specified range (typically 10-18 ohms), replace the injector.
Step 3: If the injector resistance is good, but the code persists, you'll need to test the wiring for continuity and shorts back to the PCM. This may require a wiring diagram for your specific vehicle.