What it means
Ignition Coil L Primary Control Circuit/Open: the control circuit is open. This affects the spark on the cylinder driven by this coil; a misfire results.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Ignition Coil L is the coil assigned to the L position in the vehicle's ignition system; the letter does not give a universal cylinder number. The control module monitors the L coil's primary circuit and sets this code when it detects an electrical fault there, which can leave the cylinder served by Coil L without reliable spark.
Common causes
Most likely first.
- Primary winding open
- Pin pushed back out of connector body
- Cracked solder joint inside the module or sensor
Symptoms
- Check engine light on or flashing
- Engine misfire or rough running
- Power loss or hesitation
- Hard starting
How to diagnose it
- Record freeze-frame data and inspect live misfire counts, using vehicle-specific coil mapping to locate the cylinder served by Coil L.
- Check the L coil connector and harness for a disconnected plug, damaged insulation, corrosion, or a pushed-back pin.
- Measure the Coil L power and ground supplies and compare them with the manufacturer's specification.
- With power off and the circuit isolated as specified, test the L coil primary circuit and wiring for an open.
- If the coil and circuit are intact, test the module's L-channel output according to the manufacturer's procedure.
Common fixes
- Reconnect or secure the Coil L connector.
- Repair damaged wiring or replace a loose or corroded terminal in the L primary circuit.
- Replace Coil L if it fails the manufacturer's test.
- Repair or replace the control module only if its L-channel driver is confirmed faulty.
Can I keep driving?
A misfire can damage the catalytic converter; avoid hard acceleration and stop driving if the check-engine light flashes. If it is steady and the engine runs smoothly, keep driving to a minimum until Coil L is diagnosed.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.