P28B9

Cylinder 11 Ion Current Sense Circuit Range/Performance

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$6–56 (est.)

Symptoms

Unstable engine operation
Increased fuel consumption
Power Loss
Check Engine Light Illuminates
Possible misfires

Causes

Open or short circuit in the ion current circuit
Faulty spark plug
Problems with the ignition coil
Engine control unit malfunction
Poor contact in connectors

How to Fix

Check the integrity of the ion current circuit wiring
Inspect and, if necessary, replace the spark plug
Check the condition of the ignition coil
Scan the control unit for errors
Check contacts in connectors

Related codes

P28B8 P28BA P0300