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Home >> Toyota >> 2004 >> Matrix Base, FWD, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 137 (Engine Control System Self Diagnostics (2UZ-FE)) >> Diagnostic Tests >> DTC P2121: Throttle/Pedal Position Sensor/Switch "D" Circuit Range/Performance Problem >> Diagnosis & Repair
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Diagnosis & Repair

WARNING: This page is about a different car, the 2003 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.
  1. If Toyota hand-held tester is available, go to next step. If Toyota hand-held tester is not available, go to step  3.
  2. Connect Toyota hand-held tester to Data Link Connector (DLC3) at driver's side of instrument panel. See Figure. Turn ignition on and then turn hand-held tester on. Using hand-held tester, monitor accelerator pedal position sensor voltages for VPA1 and VPA2 circuits with accelerator pedal depressed and released. See ACCELERATOR PEDAL POSITION SENSOR VOLTAGE . If voltages are not within specification, replace accelerator pedal rod assembly located on accelerator pedal. If voltages are within specification, replace ECM. ECM is located behind glove box. See Figure.
  3. Remove glove box for access to ECM with electrical connectors still installed on ECM. See Figure. Turn ignition on. Backprobing, measure voltage between specified ECM connector terminals. See ACCELERATOR PEDAL POSITION SENSOR VOLTAGE . If voltage is as specified, replace ECM. If voltage is not as specified, go to next step.
    ACCELERATOR PEDAL POSITION SENSOR VOLTAGE

    ECM Connector E8 Terminals No. Volts
    Accelerator Pedal Depressed (1)
    22 (+) - 28 (-) 2.6-4.5
    23 (+) - 29 (-) 3.4-5.3
    Accelerator Pedal Released (1)
    22 (+) - 28 (-) 0.5-1.1
    23 (+) - 29 (-) 1.2-2.0
    (1) Observe polarity with voltmeter probes.
  4. Turn ignition off. Disconnect ECM 31-pin connector E8 and accelerator pedal position sensor 6-pin connector. Check continuity between ground and accelerator pedal position sensor 6-pin connector terminals, individually. Continuity should not exist. Then, check continuity between specified accelerator pedal position sensor 6-pin connector terminals and specified ECM 31-pin connector E8 terminals. See ECM/APP SENSOR CONTINUITY . See Figure. If continuity is as specified, replace accelerator pedal rod assembly located at accelerator pedal. If continuity is not as specified, repair or replace wires and/or connectors as necessary.
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