Fault codeP0028

Intake Valve Control Solenoid Circuit Range/Performance (Bank 2)

What this code means

Intake Valve Control Solenoid Circuit Range/Performance (Bank 2).

“Bank 1” is the side of the engine that holds cylinder number 1; “Bank 2” only exists on V and flat engines. An in-line engine has a single bank.

P0028 is a generic code: it means the same thing on every make. P0028 belongs to family P00xx — Fuel and air metering, auxiliary emission controls. Its page explains how to read a code and groups all its codes by part.

Type of fault

The signal stays within its electrical limits, but its value is not plausible: it does not match what the control unit expects given the other sensors. The sensor may be drifting with age, but it may also be faithfully measuring a real mechanical problem — a leak, a blockage, an air leak. Replacing the sensor without checking does not always clear the fault.

Variable valve timing (camshaft actuator)

Many engines can shift the timing of their camshafts while running, using an oil-pressure actuator (phaser) on the end of the camshaft, controlled by a solenoid valve. The control unit advances or retards the cams to balance power, consumption and emissions, and checks with the camshaft sensor that the position it asked for is reached.

What you notice

Rough idle, lack of power at low or high revs depending on the position the cam is stuck in, higher consumption; on some engines a rattle at start-up from the phaser.

How to check it

Oil is the first suspect: a low level, the wrong viscosity or sludge prevents the actuator from moving. Check the level and the service history, then the solenoid valve (its resistance, its connector, and its fine filter screen which can clog). The phaser itself and the timing chain come next.

Watch it live in Klaro

With an OBD2 adapter plugged in, these live readings show the part at work, when your car reports them:

• Engine RPM
• Timing advance
• Calculated engine load

What to do

Have it checked this week. The car remains usable, but the fault will not clear itself and will fail the roadworthiness test.

How to read this code

• PPowertrain
• 0standardised code
• 0Fuel and air metering, auxiliary emission controls
• 28P0028

Other codes for the same part

• P0013B Camshaft Position - Actuator Circuit (Bank1)
• P0014B Camshaft Position - Timing Over-Advanced or System Performance (Bank 1)
• P0015B Camshaft Position - Timing Over-Retarded (Bank 1)
• P0020A Camshaft Position Actuator Circuit (Bank 2)
• P0021A Camshaft Position - Timing Over-Advanced or System Performance (Bank 2)
• P0022A Camshaft Position - Timing Over-Retarded (Bank 2)
• P0023B Camshaft Position - Actuator Circuit (Bank 2)
• P0024B Camshaft Position - Timing Over-Advanced or System Performance (Bank 2)
• P0025B Camshaft Position - Timing Over-Retarded (Bank 2)
• P0026Intake Valve Control Solenoid Circuit Range/Performance (Bank 1)
• P0027Exhaust Valve Control Solenoid Circuit Range/Performance (Bank 1)
• P0029Exhaust Valve Control Solenoid Circuit Range/Performance (Bank 2)