Toyota FJ Cruiser (GSJ 10, 15 series). Instruction - part 88

1GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEM

ES–307

ES

(a) Disconnect the A2 APP sensor connector.
(b) Turn the ignition switch ON.
(c) Measure the voltage between the terminals of the E47 

ECM connector.
Standard Voltage

(d) Reconnect the APP sensor connector.

NG

OK

Replace the accelerator pedal rod assembly (See page 

ES-

449

).

NEXT

(a) Connect an intelligent tester to the DLC3.
(b) Turn the ignition switch ON and turn the tester ON.
(c) Clear DTCs (See page 

ES-38

).

(d) Start the engine.
(e) Allow the engine to idle for 15 seconds.
(f)

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

(g) Read DTCs.

Result

B

3

INSPECT ECM (VCPA AND VCP2 VOLTAGE)

E47

ECM Connector

Accelerator Pedal 
Position Sensor 
Connector

EPA2 (-)

EPA (-)

VCPA (+)

VCP2 (+)

A2

A116173E03

Tester Connections

Specified Conditions

VCPA (E47-26) - EPA (E47-20)

4.5 to 5.5 V

VCP2 (E47-27) - EPA2 (E47-21)

REPLACE ECM (See page 

ES-446

)

4

REPLACE ACCELERATOR PEDAL ROD ASSEMBLY

5

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

Display (DTC Output)

Proceed To

P2120, P2122, P2123, P2125, P2127, P2128 and/or P2138

A

No output

B

SYSTEM OK

ES–308

1GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEM

ES

A

REPLACE ECM (See page 

ES-446

)

1GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEM

ES–309

ES

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

DESCRIPTION

Refer to DTC P2120 (See page 

ES-296

).

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 voltage outputs of VPA and VPA2 deviates from the standard, the ECM 
determines that the accelerator pedal position sensor is a malfunctioning. The ECM turns on the MIL and 
the DTC is set.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

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 ignition switch is turned OFF, the fail-safe operation stops and 
the system returns to a normal condition.

DTC

P2121

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

DTC No.

DTC Detection Conditions

Trouble Areas

P2121

Difference between VPA and VPA2 less than 0.4 V, or more 
than 1.2 V for 0.5 seconds (1 trip detection logic)

•

Accelerator pedal position sensor

•

ECM

Related DTCs

P2121: Accelerator pedal position (APP) sensor rationality

Required Sensors/Components (Main)

APP sensor

Required Sensors/Components (Related)

-

Frequency of Operation

Continuous

Duration

0.5 seconds

MIL Operation

Immediate

Sequence of Operation

None

Monitor runs whenever following DTCs not present

None

Either of following conditions 1 or 2 met:

-

1. Ignition switch

ON

2. Throttle actuator power

ON

Difference between VPA voltage (learned value) and VPA2 voltage (learned value)

Less than 0.4 V, or more than 1.2 V

ES–310

1GR-FE ENGINE CONTROL SYSTEM  –  SFI SYSTEM

ES

WIRING DIAGRAM

Refer to DTC P2120 (See page 

ES-300

).

INSPECTION PROCEDURE

HINT:
Read freeze frame data using an intelligent tester. Freeze frame data record 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.

(a) Connect an intelligent tester to the DLC3.
(b) Turn the ignition switch ON and turn the tester ON.
(c) Select the following menu items: DIAGNOSIS / 

ENHANCED OBD II / DATA LIST / ETCS / ACCEL POS 
#1 and ACCEL POS #2.

(d) Read the values displayed on the tester.

Standard Voltage

OK

NG

NG

OK

Replace the accelerator pedal rod assembly (See page 

ES-

449

).

NEXT

(a) Connect an intelligent tester to the DLC3.
(b) Turn the ignition switch ON and turn the tester ON.
(c) Clear DTCs (See page 

ES-38

).

(d) Start the engine.
(e) Allow the engine to idle for 15 seconds.

1

READ VALUE USING INTELLIGENT TESTER (ACCEL POS #1 AND ACCEL POS #2)

Depressed

Released

FI07052E06

Accelerator Pedal

Operations

ACCEL POS #1

ACCEL POS #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

              Go to step 3

2

CHECK HARNESS AND CONNECTOR (ACCELERATOR PEDAL POSITION SENSOR - 
ECM) (See page ES-306)

REPAIR OR REPLACE HARNESS OR 
CONNECTOR

3

REPLACE ACCELERATOR PEDAL ROD ASSEMBLY

4

CHECK WHETHER DTC OUTPUT RECURS (DTC P2121)