What it means
The ignition E control signal circuit is open — typically the PCM drive line for the first ignition coil group has lost continuity.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The ignition E control signal circuit carries a command from the powertrain control module to the ignition coil group identified as E. The PCM sets P035A when it detects an open, meaning the control signal lacks continuity and the affected coil group may not fire correctly.
Common causes
Most likely first.
- Open wire between PCM and coil
- 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 use a scan tool to check misfire counts and determine which cylinders are affected when the ignition E signal fault appears.
- Inspect the PCM and ignition E circuit connectors for loose, corroded, or pushed-back pins and check the harness for visible breaks or chafing.
- Use the wiring diagram to check continuity through the ignition E control wire between the PCM and the coil group, following the manufacturer's specification.
- Check the coil group connector and supply circuit to distinguish an open control signal from a power or connection problem.
- If the wiring and connectors pass, test the PCM ignition E output using the manufacturer's diagnostic procedure.
Common fixes
- Reseat a loose or pushed-back terminal in the ignition E signal connectors.
- Repair a break in the control wire between the PCM and ignition coil group.
- Repair corroded or damaged connector terminals in the ignition E circuit.
- Repair or replace the PCM only if its ignition E output is confirmed faulty.
Can I keep driving?
If the affected cylinders are misfiring or the check-engine light flashes, stop driving when safe because continued misfire can damage the catalytic converter. If the light is steady and the engine runs smoothly, limit driving and arrange prompt diagnosis.
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.