P0090

Fuel Pressure Regulator 1 Control Circuit

Car Fault Codes Fuel & air

Can you still drive? With care, short trips only

Who can fix it? Needs a workshop

Typical repair time 30 minutes – 4 hours

Typical cost SAR 100 to 5,000

What it means

The engine computer has detected an electrical fault in the fuel pressure regulator control circuit, most often an open circuit in the wiring or the regulator coil. When the computer loses control of the regulator, the engine may enter limp mode with reduced power, and it may be hard to start or stall.

Symptoms4

Check engine light on.
Reduced power or limp mode.
Hard starting, or a no-start on some vehicles.
Stalling or rough running.

Possible causes5

Corroded or loose regulator connector.
Broken or chafed wiring between the regulator and the ECU.
Open coil inside the regulator.
Lost power feed from a fuse or relay, on vehicles that supply it this way.
ECU fault (rare).

How to diagnose5

Read all codes, and note any battery voltage codes or other circuits that share the same feed.
Visually inspect the connector and wiring for corrosion or loose pins.
Unplug the regulator, measure its coil resistance and compare it with the manufacturer specification.
Check the power feed and the continuity of the control wire back to the ECU.
Command the regulator with a scan tool if possible, and watch the pressure respond.

How to fix5

Clean and reseat the connector and repair any corroded pin.
Repair broken or chafed wiring and remove any short to ground.
Replace a blown fuse after removing the cause of the short.
Replace the pressure regulator if its coil resistance is out of specification, or the high-pressure pump if the regulator is part of it.
Clear the codes, road test and confirm pressure returns to its desired value and the code does not return.

Repair cost

0–500

500–2,000

2,000–5,000

5,000+

In Saudi riyals; the highlighted part is the expected range for this fault.

The cost is low when a connector or wire is to blame, rises for a new regulator, and reaches the upper end on engines where the regulator is part of the high-pressure pump.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions

Does this code mean the high-pressure pump is bad?

Not necessarily. This is an electrical circuit code, and a wire or connector is often the cause. On some engines, though, the regulator is mounted on the high-pressure pump and sold with it.

Can I drive with this code?

Carefully and for a short distance. The engine may run weakly in limp mode, and on some vehicles it may stall or not start, so repair it soon.

This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.

Report a mistake

Spotted something inaccurate? Tell us and we will review and correct it.