Faulty ignition coil or integrated coil driver on cylinder E; Damaged, chafed or shorted wiring in the coil E control circuit; Corroded, loose or pushed-back pins in the coil connector or engine control unit connector; Poor or missing power or earth supply to the coil; Worn spark plug or plug lead causing excessive coil load and driver stress; Internal fault in the engine control unit ignition driver.

P035B

Ignition E Control Signal Circuit Low.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
3: AreaIgnition system or misfire
5B: FaultThe specific fault in that area

What it means

P035B is a generic code meaning the engine control unit has detected a low voltage or signal level in the control circuit for ignition coil E, normally the fifth coil in the firing order or as labelled by the manufacturer. The control unit monitors the ignition trigger signal it sends to the coil driver and found it lower than expected, which points to a short to earth, an open circuit, or a fault in the driver or coil.

Symptoms

Engine misfire, especially under load or at idle
Rough running or hesitation
Illuminated check engine light, possibly flashing during a misfire
Reduced power and poor fuel economy
Hard starting or intermittent no-start
Engine running in a reduced-performance mode on some models

Possible causes

Faulty ignition coil or integrated coil driver on cylinder Elikely
Damaged, chafed or shorted wiring in the coil E control circuitlikely
Corroded, loose or pushed-back pins in the coil connector or engine control unit connectorpossible
Poor or missing power or earth supply to the coilpossible
Worn spark plug or plug lead causing excessive coil load and driver stresspossible
Internal fault in the engine control unit ignition driverrare

How to diagnose

Read all stored and pending codes and note freeze frame data such as engine speed, load and temperature to see when the fault set
Check for related misfire codes and confirm which cylinder is coil E on this engine, as the lettering and firing order vary by model
Visually inspect the coil connector and harness for chafing, heat damage, oil contamination and corrosion
Check the coil power supply and earth with a multimeter against the wiring diagram for the model
Swap coil E with another cylinder's coil and see whether the fault or misfire follows the coil
Test the control signal wire for continuity, short to earth and short to supply between the coil and control unit
Inspect the spark plug for wear, fouling and correct gap, and replace if out of specification
Check the engine control unit connector pins and, if everything else is sound, consider control unit testing as a last step

How to fix

Replace the faulty ignition coil for cylinder E
Repair or replace damaged wiring or the connector in the control circuit
Clean or repair corroded terminals and secure loose connections
Restore the coil power supply or earth connection if it is faulty
Fit new spark plugs of the correct specification if worn
Repair or replace the engine control unit only after all wiring and component faults are ruled out

Can I keep driving?

Medium severity

The car can be driven gently for a short time to get it repaired, but avoid heavy loads. If the check engine light flashes, reduce speed and stop driving, as unburnt fuel can damage the catalytic converter.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.