Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the computer in your car is having trouble understanding the information from the injector on cylinder number 6. It's like when you try to read a book in a language you don't know.
The engine control module (ECM) is receiving data from the injector on cylinder 6 that it cannot process or understand.
P2691 is triggered when the ECM detects that the data being received from the fuel injector for cylinder 6 is not compatible with expected parameters. This can be due to a mismatch in the injector's calibration or a communication error.
• Check engine light is on
• Engine misfire or rough running
• Decreased fuel efficiency
• Faulty injector on cylinder 6
• Wiring issues or poor connections
• ECM software or hardware problems
ECM: Engine Control Module
Injector: A component that sprays fuel into the engine's cylinders
• Use an OBD-II scanner to confirm the code.
• Inspect the wiring and connectors for cylinder 6 injector.
• Test the injector for proper operation.
• Repair or replace faulty wiring or connectors.
• Replace the injector on cylinder 6 if defective.
• Update or reprogram the ECM if necessary.
• OBD-II scanner
• Multimeter
• Injector tester
$150 - $500
Moderate
• Ford F-150
• Chevrolet Silverado
• Dodge Ram 1500
• Regular maintenance and inspections
• Ensure proper fuel quality
• Keep electrical connections clean and secure
Engine Performance
• Avoid driving the vehicle until the issue is resolved to prevent further damage.
• Consult with a professional mechanic for accurate diagnosis and repair.
Check with your vehicle manufacturer for warranty coverage on injectors and ECM issues.
This code has been more common in vehicles with high mileage or those that have had previous injector issues.
Moderate – Address this issue soon to prevent engine performance problems.
Driving with this code may lead to increased emissions and potential engine damage.
• Engine running
• Vehicle at operating temperature
The injector for cylinder 6 is located on the engine block, typically near the intake manifold on the side of the engine corresponding to cylinder 6.
Q: Can I drive with a P2691 code?
A: It's not recommended to drive with this code as it can lead to engine performance issues and potential damage.
Q: How do I know if my injector is faulty?
A: Symptoms of a faulty injector include engine misfires, rough idling, and decreased fuel efficiency. A professional diagnosis is recommended.
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Universal · Digital multimeter
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Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
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Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
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Fitment Required · Vehicle-fitment part
Commonly relevant for misfire, ignition-efficiency, and some drivability-related repairs.
Misfire and ignition-related faults commonly involve spark plugs as part of the repair path.
Check the correct plug type, gap, and engine application for your vehicle.
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Fitment Required · Vehicle-fitment part
Relevant when the fault points toward ignition-coil performance or cylinder-specific ignition issues.
Some ignition faults involve coil performance or cylinder-specific coil problems.
Match the coil to your engine and confirm the failed component before ordering.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.