Brand:

Toyota

Model Name:

4Runner GRN210 215 UZN210 215

Manual:

Repair Manual

Section:

1Gr-Fe Engine Control System

Title:

Sfi System

  1. Description

  2. Monitor description

  3. Monitor strategy

  4. Typical enabling conditions

  5. Typical malfunction thresholds

  6. Fail-safe

  7. Wiring diagram

  8. Inspection procedure

  9. Read value of intelligent tester (accel pos #1 and accel pos #2)

  10. Check harness and connector (accelerator pedal position sensor - ecm)

  11. Replace accelerator pedal rod assembly

  12. Check whether dtc output recurs (accelerator pedal position sensor dtcs)

DTC P2121 Throttle / Pedal Position Sensor / Switch "D" Circuit Range / Performance

HINT:
This DTC relates to the Accelerator Pedal Position (APP) sensor.

DESCRIPTION

Refer to DTC P2120 (Click here).

DTC No.
DTC Detection Conditions
Trouble Areas
P2121
Difference between VPA and VPA2 is less than 0.4 V, or more than 1.2 V for 0.5 second (1 trip detection logic)
  1. APP sensor
  2. ECM

MONITOR DESCRIPTION

The accelerator pedal position sensor is mounted on the accelerator pedal bracket. The accelerator pedal position sensor has 2 sensor elements and 2 signal outputs: VPA1 and VPA2. VPA1 is used to detect the actual accelerator pedal angle (used for engine control) and VPA2 is used to detect malfunctions in VPA1. When the difference between the voltage outputs of VPA1 and VPA2 deviates from the standard, the ECM concludes the accelerator pedal position sensor has a malfunction. The ECM turns on the MIL and a DTC is set.

MONITOR STRATEGY


Related DTCs
P2121: Accelerator pedal position (APP) sensor (rationality)
Required Sensors / Components (Main)
Accelerator position sensor
Required Sensors / Components (Related)
-
Frequency of Operation
Continuous
Duration
0.5 seconds
MIL Operation
Immediate
Sequence of Operation
None

TYPICAL ENABLING CONDITIONS


The monitor will run whenever these DTCs are not present
None
Either of the following conditions is met
Condition 1 or 2
1. Ignition switch
ON
2. Throttle control motor power
ON

TYPICAL MALFUNCTION THRESHOLDS


Difference between VPA1 voltage (learned value) and VPA2 voltage (learned value)
Less than 0.4 V, or more than 1.2 V

FAIL-SAFE

The accelerator pedal position sensor has 2 (main and sub) sensor circuits. If a malfunction occurs in either of the sensor circuits, the ECM detects the abnormal signal voltage difference between the 2 sensor circuits and switches to limp mode. In limp mode, the functioning circuit is used to calculate the accelerator pedal opening angle to allow the vehicle to continue driving. If both circuits malfunction, the ECM regards the opening angle of the accelerator pedal to be fully closed. In this case, the throttle valve will remain closed as if the engine is idling.
If a "pass" condition is detected and then the ignition switch is turned off, the fail-safe operation will stop and the system returns to a normal condition.

WIRING DIAGRAM

Refer to DTC P2120 (Click here).

INSPECTION PROCEDURE

HINT:
Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air/fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
1.READ VALUE OF INTELLIGENT TESTER (ACCEL POS #1 AND ACCEL POS #2)
  1. Connect the intelligent tester to the DLC3. 4Runner

  2. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch on and turn the tester on.

  1. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / ACCEL POS #1 and ACCEL POS #2.

  1. Read the values displayed on the tester.

    Standard voltage:
    Accelerator Pedal Operations
    		ACCEL POS #1 (AP#1)
    		ACCEL POS #2 (AP#2)
    Released
    		0.5 to 1.1 V
    		1.2 to 2.0 V
    Depressed
    		2.6 to 4.5 V
    		3.4 to 5.0 V


OKnext
Go to step 4
NG
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2.CHECK HARNESS AND CONNECTOR (ACCELERATOR PEDAL POSITION SENSOR - ECM)
  1. Disconnect the A24 Accelerator Pedal Position (APP) sensor connector. 4Runner

  2. Disconnect the A24 Accelerator Pedal Position (APP) sensor connector.

  1. Disconnect the E8 ECM connector.

  1. Measure the resistance.

    Standard resistance (Check for open):
    Tester Connections
    		Specified Conditions
    VPA1 (A24-6) - VPA (E8-18)
    		Below 1 Ω
    EP1 (A24-5) - EPA (E8-20)
    		Below 1 Ω
    VCP1(A24-4) - VCPA (E8-26)
    		Below 1 Ω
    VPA2 (A24-3) - VPA2 (E8-19)
    		Below 1 Ω
    EP2 (A24-2) - EPA2 (E8-21)
    		Below 1 Ω
    VCP2 (A24-1) - VCP2 (E8-27)
    		Below 1 Ω
Standard resistance (Check for short):
Tester Connections
Specified Conditions
VPA1 (A24-6) or VPA (E8-18) - Body ground
10 kΩ or higher
EP1 (A24-5) or EPA (A24E8-20) - Body ground
10 kΩ or higher
VCP1 (A24-4) or VCPA (E8-26) - Body ground
10 kΩ or higher
VPA2 (A24-3) or VPA2 (E8-19) - Body ground
10 kΩ or higher
EP2 (A24-2) or EPA2 (E84-21) - Body ground
10 kΩ or higher
VCP2 (A24-1) or VCP2 (E8-27) - Body ground
10 kΩ or higher

  1. Reconnect the APP sensor connector.

  1. Reconnect the ECM connector.



NGnext
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
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3.REPLACE ACCELERATOR PEDAL ROD ASSEMBLY

  1. Replace the accelerator pedal rod assembly (Click here).


NEXT
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4.CHECK WHETHER DTC OUTPUT RECURS (ACCELERATOR PEDAL POSITION SENSOR DTCS)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch on and turn the tester on.

  1. Clear DTCs (Click here).

  1. Start the engine.

  1. Allow the engine to idle for 15 seconds.

  1. Select the following menu items on the tester: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.

  1. Read DTCs.

    Result:

    Display (DTC Output)
    		Proceed to
    P2121
    		A
    No output
    		B


Bnext
SYSTEM OK
A
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REPLACE ECM