P2331 OBD-II Trouble Code: Ignition Coil K Primary Control Circuit High

P2331 code definition

Ignition Coil K Primary Control Circuit High

What the P2331 code means

P2331 is an OBD-II generic code for the Ignition Coil K Primary Control Circuit High to the Engine Control Module (ECM). This means the primary coil circuit has an short circuit causing the high voltage signal to the ECM.

What causes the P2331 code?

• The ECM got a high voltage signal return on the primary circuit of the coil

• The coil could be shorted internally in the primary circuit

• The wiring or connection to the coil may have a shorted to power wire on the primary circuit

What are the symptoms of the P2331 code?

• The Check Engine Light will be illuminated and the code set in ECM memory as a fault.
• The engine fault may be P2331, and also a misfire code to the cylinder.
• The engine will run rough and hesitate.
• The short may be caused by internal damage to the ECM.

How does a mechanic diagnose the P2331 code?

• Scans and documents codes in the ECM
• Diagnoses as per the manufacturer's pinpoint test to check the primary circuit of the coil
• Clears the ECM code P2331 and verifies whether the code comes back
• Tests the coil primary internal circuit for continuity to be within specification or shorted
• Tests and checks the primary coil connector and wiring for shorts in the wiring

Common mistakes when diagnosing the P2331 code

• Clearing ECM memory codes before checking the freeze frame data of the failure
• Failing to clear ECM codes after the P2331 codes are fixed
• Replacing the defective coil without checking or replacing the spark plug
• Replacing primary damaged wiring with an incorrect size wire

How serious is the P2331 code?

Code P2331 is an indication that the coil primary circuit has failed and the coil is not firing any more. This will cause the engine to misfire on the cylinder with the defective coil.

What repairs can fix the P2331 code?

• Replacing the coil
• Repairing the wiring or connection to the coil assembly
• Replacing the ECM for a shorted internal primary circuit failure

Additional comments for consideration regarding the P2331 code

Code P2331 is common with vehicles that have a 12 cylinder motor and with coils on each cylinder. The primary circuit is what powers and fires the coil. Shorted primary circuits may blow a fuse on some vehicles.

Need help with a P2331 code?

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