SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSTOYOTA2004CELICA GT, STANDARDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT VARIANT/TRIMSECTION 5 (ENGINE CONTROLS (2ZZ-GE) - DIAGNOSTICS)CIRCUIT INSPECTIONDTC P2121: THROTTLE/PEDAL POSITION SENSOR/SWITCH "D" CIRCUIT RANGE/PERFORMANCEINSPECTION PROCEDUREHAND-HELD TESTER
2004 Toyota Celica GT, Standard

Hand-held tester

2004 Toyota Celica GT, StandardSECTION Hand-held tester
WARNING: This page is about a different variant/trim than selected.
  1. Connect hand-held tester, and read the voltage for accelerator pedal position sensor data. 

    PREPARATION: 

    1. Connect the hand-held tester to the DLC3.
    2. Turn the ignition switch ON and push the hand-held tester main switch ON.

    CHECK: 

    Read the voltage for the accelerator pedal position sensor data.

    Fig 1: Identifying Accelerator Pedal Depressed And Released
    G02897897Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: 

    ACCELERATOR PEDAL POSITION SENSOR VOLTAGE REFERENCE

    Accelerator pedal VPA1 VPA2
    Released 0.5 to 1.1 V 1.2 to 2.0 V
    Depressed 2.6 to 4.5 V 3.4 to 5.3 V
    1. OK : Replace ECM (See ENGINE CONTROL MODULE (ECM) in  SFI  ). 
    2. NG : Go to next step. 
  2. Check for open and short in harness and connector between accelerator pedal position sensor and ECM (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 
    1. NG : Repair or replace harness or connector. 
    2. OK : Replace accelerator pedal position sensor. 
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

Shop Manual-Ready ToolsFree Quote CheckQuote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.