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Home >> Lexus >> 2012 >> LS 460 AWD V8-4.6L (1UR-FSE) >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P2121

P2121





1UR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P2121: Throttle / Pedal Position Sensor / Switch "D" Circuit Range / Performance
P2121 - Throttle / Pedal Position Sensor / Switch "D" Circuit Range / Performance

DESCRIPTION

Refer to DTC P2120 P2120.





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: VPA and VPA2. VPA is used to detect the actual accelerator pedal angle (used for engine control) and VPA2 is used to detect malfunctions in VPA. When the difference between the output voltages of VPA and VPA2 deviates from the standard, the ECM determines that the accelerator pedal position sensor is malfunctioning. The ECM turns on the MIL and stores the DTC.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

ALL (Case 1 and Case 2)





Case 2





TYPICAL MALFUNCTION THRESHOLDS

Case 1





Case 2





CONFIRMATION DRIVING PATTERN





1. Connect the Techstream to the DLC3.

2. Turn the engine switch on (IG) and turn the Techstream ON.

3. Clear DTCs (even if no DTCs are stored, perform the clear DTC procedure).

4. Turn the engine switch off and wait for at least 30 seconds.

5. Turn the engine switch on (IG) and turn the Techstream on [A].

6. Wait for 5 seconds after turning the engine switch on (IG).

7. Operate the accelerator pedal in accordance with the following procedure [B].

a. Enter the following menus: Powertrain / Engine / Data List / Gas Throttle / Accel Sens. No. 1 Volt %, and Accel Sens. No.2 Volt %.

b. Slowly depress the accelerator pedal until Accel Sens. No.1 Volt % is approximately 30% and Accel Sens. No.2 Volt % is approximately 46%, then slowly release the accelerator pedal.

8. Enter the following menus: Powertrain / Engine / Trouble Codes [C].

9. Read pending DTCs.

HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.

10. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

11. Input the DTC: P2121.

12. Check the DTC judgment result.





HINT
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows INCOMPLETE or N/A, perform steps [B] through [C] again.

13. If no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

FAIL-SAFE

The accelerator pedal position sensor has two (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 two 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 as being fully closed. In this case, the throttle valve remains closed as if the engine is idling.

If a pass condition is detected and then the engine switch is turned off, the fail-safe operation stops and the system returns to a normal condition.

WIRING DIAGRAM

Refer to DTC P2120 P2120.

INSPECTION PROCEDURE

HINT
- Read freeze frame data using the Techstream. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
- This DTC relates to the Accelerator Pedal Position (APP) sensor.

PROCEDURE

1. READ VALUE USING TECHSTREAM (ACCELERATOR POSITION SENSOR) P2120

OK -- REPLACE ACCELERATOR PEDAL ROD ASSEMBLY
NG -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (ACCELERATOR PEDAL POSITION SENSOR - ECM) P2120

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

3. REPLACE ACCELERATOR PEDAL ROD ASSEMBLY

(a) Replace the accelerator pedal rod assembly Removal.

NEXT -- Continue to next step.

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

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG) and turn the Techstream on.

(c) Clear DTCs Reading and Clearing Diagnostic Trouble Codes.

(d) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

(e) Enter the following menus: Powertrain / Engine / Trouble Codes.

(f) Read DTCs.

Result:





B -- SYSTEM OK

A -- REPLACE ECM Removal
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