P1128Manufacturer-specific code

P1128 Code: Throttle Control Motor Locked (Toyota)

On Toyota and Lexus, the P1128 code means the throttle control motor is locked. The engine goes into limp mode with very little power. On other brands the number means something else.

Severity
High
Can I keep driving?
Yes, but with caution
Estimated cost
$0 to $600
Difficulty
Medium
System
Idle and Speed Control
Applies to
Depends on the manufacturer

Common in: Audi, Seat, Toyota, Volkswagen

Updated Reviewed by Renzo Chacca

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What the P1128 code means

P1128 is a manufacturer-specific code: the 1 in the second position means each automaker defines what it stands for, not the generic standard. That is why the same number means different things depending on the vehicle, as the table below shows. This page covers the Toyota and Lexus meaning.

ManufacturerMeaning of P1128
Toyota and LexusThrottle control motor locked
Volkswagen, Audi, Seat and SkodaLong term fuel trim, multiplicative, bank 1: system too lean

Toyotas with an electronic throttle (ETCS-i) move the throttle plate with an electric motor controlled by the computer, which reads the pedal with two sensors. When it detects a fault, it goes into limp mode: a spring holds the throttle plate almost closed and the engine barely accelerates.

The computer sets the P1128 code when it commands the throttle plate to move and the position sensor detects no movement.

Before you repair anything, confirm the make, model, year and engine. With manufacturer codes, the same number can change even between engines from the same brand.

P1128 code symptoms

  • Check engine light on.
  • Limp mode: the engine barely accelerates.
  • High or unstable idle.
  • The engine may stall.

Likely causes of the P1128 code

  1. Throttle plate stuck from dirt. The most frequent cause.
  2. Ice on the throttle plate in cold climates.
  3. Damaged motor or gears. Confirm it with the tests in the diagnosis section.
  4. Broken return spring. Confirm it with the tests in the diagnosis section.

How to diagnose the P1128 code step by step

  1. Read all stored codes and the live data for the pedal and the throttle plate.
  2. Clean the throttle body with the ignition off.
  3. Check the connectors at the throttle body and at the pedal.
  4. Check the battery and the grounds.
  5. Perform the idle relearn if the manufacturer calls for it.

How to fix the P1128 code

  • Clean or replace the throttle body.
  • Replace the pedal if its sensors fail.
  • Repair the connectors or the wiring.
  • Clear the codes, confirm that the P1128 code does not come back, and verify the repair on a test drive.

Technical reference data

  • Throttle motor: approximate resistance of 0.3 to 100 ohms depending on the model; check the service manual.
  • Pedal: two signals, VPA and VPA2, that must move in parallel.
  • P1xxx codes are manufacturer-specific: confirm the definition with a scan tool that supports your brand.
  • Values are approximate: check the manufacturer data for your vehicle.

Brand-specific notes

Common on Corolla, Camry, RAV4 and Tacoma models from the 2000s.

If your vehicle is another brand, check the table above for the meaning its manufacturer gives the code, and confirm it with a scan tool that supports that brand.

Frequently asked questions about P1128

What does the P1128 code mean on a Toyota?
It means the throttle control motor is locked. The engine goes into limp mode with very little power.
Does P1128 mean the same thing on every brand?
No. On Volkswagen it stands for the long term fuel trim, multiplicative, bank 1: system too lean.
Can I drive with a P1128 code?
Only with great caution. Power is minimal, and that can be dangerous on fast roads or when merging. Drive straight to a shop at low speed if you must move the vehicle.
How much does it cost to fix P1128?
On a Toyota the cost runs from about $0 to $600. A throttle body cleaning is cheap, while a replacement throttle body costs more.
Will a P1128 code clear itself?
If the cause was ice or a temporary sticking, it may clear once the engine warms up. Dirt buildup or a broken spring will bring the code back until they are fixed.
What is the most common cause of P1128?
A throttle plate stuck from dirt and carbon. Ice in cold weather, damaged gears and a broken return spring are the other suspects.

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