Open circuit in the ignition coil control wire between the PCM and the coil; Failed ignition coil with an open primary winding; Corroded or loose electrical connector at the ignition coil or PCM; Damaged or shorted wiring harness causing an open circuit; Faulty powertrain control module (PCM) driver circuit; Aftermarket alarm or remote start system improperly tapped into the ignition circuit

DTC codes / P03xx · Ignition system and misfire / P035C

P035CIgnition E Control Signal Circuit High

Q: What does code P035C mean?

Ignition E Control Signal Circuit High. P035C indicates that the powertrain control module (PCM) has detected an abnormally high voltage on the ignition coil control circuit for cylinder E, which is typically the fifth cylinder in the engine's firing order. The PCM commands the coil to fire by grounding the control circuit, so a high-voltage reading means the circuit is not being pulled low as expected, often due to an open circuit or a failed coil driver.

P035C indicates that the powertrain control module (PCM) has detected an abnormally high voltage on the ignition coil control circuit for cylinder E, which is typically the fifth cylinder in the engine's firing order. The PCM commands the coil to fire by grounding the control circuit, so a high-voltage reading means the circuit is not being pulled low as expected, often due to an open circuit or a failed coil driver.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Engine misfire, especially under acceleration or load
Rough idle or shaking felt through the steering wheel and seats
Reduced engine power and poor fuel economy
Difficulty starting or a stalled engine in severe cases

Common causes, most likely first

Open circuit in the ignition coil control wire between the PCM and the coil
Failed ignition coil with an open primary winding
Corroded or loose electrical connector at the ignition coil or PCM
Damaged or shorted wiring harness causing an open circuit
Faulty powertrain control module (PCM) driver circuit
Aftermarket alarm or remote start system improperly tapped into the ignition circuit

How to diagnose and fix it

Inspect the ignition coil connector and wiring for damage, corrosion, or looseness; clean or repair as needed
Swap the ignition coil from cylinder E with a known-good coil from another cylinder and see if the code moves
Use a digital multimeter to check the resistance of the ignition coil primary circuit and compare to specifications
Check for continuity and voltage on the control circuit between the PCM and the coil while wiggling the harness to find intermittent opens
Perform a voltage drop test on the ground circuit for the ignition coil to rule out a bad ground
If the circuit and coil test good, test the PCM driver output with an oscilloscope or a noid light designed for ignition coils
Replace the faulty ignition coil or repair the wiring as needed, then clear the code and verify the repair with a test drive

Don't overlook the coil driver circuit

A high-voltage code on an ignition control circuit often points to an open circuit rather than a short, so a simple continuity test can quickly find the problem.
The PCM driver for the coil can fail and cause this code even when the coil and wiring test perfectly, so don't rule out the computer until all other possibilities are exhausted.
Aftermarket accessories like remote starters or alarm systems are frequently tapped into ignition wiring and can introduce opens or high resistance that set this code.
This code is specific to cylinder E, which is not always cylinder number 5; always confirm the firing order and cylinder numbering for the particular engine before swapping parts.
A loose or corroded ground connection at the engine block can cause a high-voltage reading on the control circuit, so inspect and clean grounds as part of the diagnosis.

Can I keep driving with P035C?

You can drive the vehicle short distances to a repair shop, but avoid heavy acceleration and prolonged driving because a persistent misfire can overheat the catalytic converter and cause expensive damage. If the check engine light is flashing, stop driving immediately and have the vehicle towed.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.