P1507 Idle speed too low (underspeed)

By: Diagno editorial team · Updated: 2026-10-15

P1507 means: Idle speed too low (underspeed). The computer holds the idle speed steady with the throttle or an idle valve. OK to drive, but have it checked soon. The most common repair costs about €90–180 in Estonia, depending on make and model. The most common cause: dirty throttle body or idle valve.

What it means

The computer holds the idle speed steady with the throttle or an idle valve. The speed is wrong or can't be held steady.

This is a make-specific code (Ford). The exact meaning can vary by model and year.

What you may notice

• Idle hunts or is too high or low
• The engine may stall
• Engine light on

What could be wrong

1. 1Dirty throttle body or idle valve · Valve replacement €90–180
2. 2Air leak · Leak check and hose or gasket replacement €60–120
3. 3Throttle needs relearning · Throttle body clean or replace €90–180
4. 4Faulty idle valve · Valve replacement €90–180

Repair difficulty: Easy

What you can check yourself

Cleaning the throttle body often helps. After cleaning or disconnecting the battery, the throttle often has to be relearned. You can do the simpler checks yourself.

How we fix it

1. We clean and relearn the throttle body
2. We check for air leaks
3. We replace the idle valve or throttle body

Standard SAE description: Idle Air Control Underspeed Error