Technical Definition:

(Ignition Coil L Primary / Secondary Circuit

Technical Description:

The COP ignition system is what is used on most modern engines. There is an individual coil for each cylinder that is controlled by the PCM (powertrain control module).

Possible Causes:

• Short to voltage or ground on COP driver circuit
• Open on COP driver circuit
• Loose connection at coil or broken connector locks
• Bad Coil (COP)
• Faulty Powertrain Control Module

Possible Symptoms:

• MIL (Malfunction indicator lamp) illumination
• Engine misfire may be present or intermittent

Ignition Coil 12 Primary/Secondary Circuit Malfunction

Possible Solutions:

OBD-II Trouble Code Type:

Diagnostic Step:

Tech Notes:

– Faulty Ignition Coil 12
– Ignition Coil 12 harness is open or shorted
– Ignition Coil 12 circuit poor electrical connection
– Faulty Engine Control Module (ECM)

Specific Makes:

– Lack/Loss of Power
– Engine may be harder to start
– Engine hesitation
– Rough engine idle