Diagnostic trouble code P2121 3UR-FE Land Cruiser

DESCRIPTION

MONITOR DESCRIPTION

FAIL-SAFE

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2121)

READ VALUE USING INTELLIGENT TESTER (ACCELERATOR POSITION SENSOR)

REPLACE ACCELERATOR PEDAL

CHECK WHETHER DTC OUTPUT RECURS (DTC P2121)

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

Description

HINT:

Refer to DTC P2120.

DTC Code	DTC Detection Condition	Trouble Area
P2121	The difference between VPA and VPA2 is below 0.4 V, or higher than 1.2 V for 0.5 seconds (1 trip detection logic).	Accelerator Pedal Position (APP) sensor ECM

Monitor description

When the difference between the output voltages of VPA and VPA2 deviates from the standard, the ECM determines that the Accelerator Pedal Position (APP) sensor is malfunctioning. The ECM turns on the MIL and the DTC is stored.

FAIL-SAFE

The Accelerator Pedal Position (APP) 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.

Inspection procedure

HINT:

1. This DTC relates to the Accelerator Pedal Position (APP) sensor.
2. Read freeze frame data using the intelligent tester. 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.

1.CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2121)

1. Connect the intelligent tester to the DLC3.

2. Turn the engine switch on (IG).

3. Turn the tester on.

4. Enter the following menus: Powertrain / Engine and ECT / DTC.

5. Read DTCs.

   Result

   Result	Proceed to
   P2121 is output	A
   P2121 and other DTCs are output	B

   HINT:

   If any DTCs other than P2121 are output, troubleshoot those DTCs first.

B	GO TO DTC CHART

A

2.READ VALUE USING INTELLIGENT TESTER (ACCELERATOR POSITION SENSOR)

1. Connect the intelligent tester to the DLC3.

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

3. Enter the following menus: Powertrain / Engine and ECT / Data List / ETCS / Accelerator Position No. 1 and Accelerator Position No. 2.

4. Read the values displayed on the tester.

   Standard Voltage:

   Accelerator Pedal Operations	Accelerator Position No. 1	Accelerator Position No. 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

NG	Go to step 3

OK
CHECK FOR INTERMITTENT PROBLEMS

3.REPLACE ACCELERATOR PEDAL

1. Replace the accelerator pedal assembly .

NEXT

4.CHECK WHETHER DTC OUTPUT RECURS (DTC P2121)

1. Connect the intelligent tester to the DLC3.

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

3. Clear DTCs .

4. Start the engine.

5. Allow the engine to idle for 15 seconds.

6. Enter the following menus: Powertrain / Engine and ECT / DTC.

7. Read DTCs.

   Result

   Result	Proceed to
   P2121 is output	A
   No DTC is output	B

B	SYSTEM OK

A
REPLACE ECM