Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there's a problem with one of the parts that helps your car engine get fuel. It's like a wire is touching something it shouldn't, causing a hiccup.
The code indicates a short circuit in the high side of the injector circuit for cylinder 11, which may affect fuel delivery.
P31BB is triggered when the Engine Control Module (ECM) detects a short circuit between the high side of the fuel injector for cylinder 11 and the ignition coil. This can disrupt the precise control of fuel injection timing and quantity, leading to engine performance issues.
• Engine misfire
• Poor fuel economy
• Check Engine Light is on
• Damaged injector wiring
• Faulty fuel injector
• Short circuit in the ignition coil wiring
Injector: A device that sprays fuel into the engine's cylinders.
Short Circuit: An electrical circuit that allows current to travel along an unintended path.
• Perform a visual inspection of the injector and coil wiring.
• Use a multimeter to check for continuity and shorts in the wiring.
• Test the injector and coil for proper operation.
• Repair or replace damaged wiring.
• Replace the faulty fuel injector.
• Repair or replace the ignition coil if necessary.
• Multimeter
• OBD-II scanner
• Basic hand tools
$150 - $500
Moderate
• Chevrolet Silverado
• GMC Sierra
• Cadillac Escalade
• Regular maintenance checks
• Avoiding exposure of wiring to harsh conditions
• Ensuring proper installation of engine components
Engine Performance
• Have the vehicle inspected by a professional mechanic.
• Avoid driving the vehicle until the issue is resolved to prevent further damage.
Check with the vehicle manufacturer for warranty coverage on engine components.
This code is relatively rare and typically associated with specific wiring or component failures.
High – Immediate attention is required to prevent engine damage.
Ignoring this issue may lead to engine damage and is not recommended for safe vehicle operation.
• Engine running
• All electrical connections secure
The fuel injector for cylinder 11 is located on the engine block, typically near the intake manifold.
Q: Can I drive with a P31BB code?
A: It's not recommended to drive with this code active as it can cause engine damage.
Q: How can I prevent this issue?
A: Regular maintenance and inspections can help prevent wiring issues that lead to this code.
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Network faults often require full-system access instead of a generic code reader alone.
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Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
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.