Diagnostic Aids
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.
After confirming DTCs P2120, P2122, P2123, P2125, P2127, P2128 and P2138 exist, use Toyota hand-held tester or scan tool to confirm throttle valve opening by reading ACCEL POS #1 and ACCEL POS #2 voltages with accelerator pedal released and depressed to determine probable cause for accelerator pedal position sensor. See THROTTLE VALVE OPENING VOLTAGE SPECIFICATIONS . Using hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.
THROTTLE VALVE OPENING VOLTAGE SPECIFICATIONS
| Accelerator Pedal Position & Accelerator Pedal Position Sensor Voltage Reading | Probable Cause | |
|---|---|---|
| Accelerator Pedal Released | ||
| ACCEL POS #1 (Zero Volts) & ACCEL POS #2 (Zero Volts) | Open In VC Circuit | |
| ACCEL POS #1 (Zero Volts) & ACCEL POS #2 (1.2-2.0 Volts) | Open Or Short To Ground In VPA1 Circuit | |
| ACCEL POS #1 (0.3-1.1 Volts) & ACCEL POS #2 (Zero Volts) | Open Or Short To Ground In VPA2 Circuit | |
| ACCEL POS #1 (5 Volts) & ACCEL POS #2 (5 Volts) | Open In E2 Circuit | |
| Accelerator Pedal Depressed | ||
| ACCEL POS #1 (Zero Volts) & ACCEL POS #2 (Zero Volts) | Open In VC Circuit | |
| ACCEL POS #1 (Zero Volts) & ACCEL POS #2 (3.4-5.3 Volts) | Open Or Short To Ground In VPA1 Circuit | |
| ACCEL POS #1 (2.6-4.5 Volts) & ACCEL POS #2 (Zero Volts) | Open Or Short To Ground In VPA2 Circuit | |
| ACCEL POS #1 (5 Volts) & ACCEL POS #2 (5 Volts) | Open In E2 Circuit | |