Engine

P1510 — Throttle Idle Position Not Learned

Severity: medium Drive with care, to a shop

What P1510 means

An electronic throttle is controlled by the ECU, which must know the exact closed-throttle position at idle. After a battery disconnect, cleaning or replacement of the throttle body, that learned value is lost or invalid, so the ECU sets this code. Idle control then becomes inaccurate. The exact definition varies by manufacturer.

Symptoms

  • High, low or hunting idle speed
  • Stalling when stopping or coasting
  • Reduced power message
  • Check Engine light on
  • Sluggish throttle response

Possible causes

  1. Throttle relearn not performed after battery disconnect
  2. Dirty throttle body
  3. New or removed throttle body without calibration
  4. Weak battery or low system voltage
  5. Faulty throttle motor or position sensors
  6. Damaged wiring or poor connector contact at the throttle

How to diagnose

  1. Scan all codes and freeze frame data, noting any throttle or pedal codes
  2. Test battery voltage and ground connections
  3. Inspect and clean the throttle body with proper cleaner, without forcing the plate by hand
  4. Check the throttle connector and wiring for corrosion or damage
  5. Review throttle and pedal position sensor data with a scan tool
  6. Run the throttle relearn procedure for your vehicle
  7. Clear the code and confirm it stays away and idle is stable
  8. If the relearn fails, check for vacuum leaks and test the throttle body

Common fixes

  • Perform the throttle relearn with a scan tool or the factory procedure
  • Clean the throttle plate and bore
  • Replace the battery or restore proper charging voltage
  • Repair the throttle connector or wiring
  • Replace and calibrate the throttle body

P1510 on different brands

Chrysler
Linked to the Back UP Power Supply circuit or function.
Land Rover
Points to a fault in the idle air control (IAC) valve opening coil circuit.
Lexus · manuals
Means intake air volume is too low with the supercharger on.
Mazda · manuals
Means a malfunction in the idle air control (IAC) system.
MINI
Means the idle speed control valve is stuck.
Opel · manuals
Points to a fault in the closed throttle position (CTP) switch circuit.
Porsche
Relates to the idle air control valve circuit or operation.
PSA
Relates to data received from the automatic gearbox ECU: a request to turn on the diagnostic LED (Siemens SID 803, 2.0 HDi).

Questions and answers

How do I clear P1510?

You usually need to run a throttle relearn, done with a scan tool on many cars or with a key-on timing routine on some. Make sure the throttle body is clean and the battery is healthy first.

Why did P1510 appear after a battery change?

Disconnecting power erases the ECU's learned values. The throttle must be relearned after reconnecting.

Can I drive with P1510?

Briefly, yes, but the engine may stall and lose power. It's best to do the relearn right away.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.