DESCRIPTION HINT: Refer to DTC P2120 (See page ). |
DTC No. | DTC Detection Condition |
Trouble Area | | P2121 |
Either conditions (1) or (2) met for 0.5 seconds (1 trip detection logic):
- (1) Difference between VPA and VPA2 is less than 0.4 V, or more than 1.2 V. (learned value of accelerator off position)
- (2) Difference between VPA and VPA2 is greater than or equal to the specified value.
|
- Accelerator pedal sensor assembly
- 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: 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 |
Related DTCs | P2121: Accelerator pedal position sensor rationality | |
Required Sensors/Components (Main) | Accelerator pedal sensor assembly | |
Required Sensors/Components (Related) |
- | | Frequency of Operation |
Continuous | | Duration |
-: Case 1 0.5 seconds: Case 2 | |
MIL Operation | Immediate | |
Sequence of Operation | None | TYPICAL ENABLING CONDITIONS ALL (Case 1 and Case 2) |
Monitor runs whenever following DTCs not stored |
P2120, P2122, P2123, P2125, P2127, P2128, P2138 (Accelerator pedal position sensor) | |
Either of following conditions 1 or 2 met: |
- | | 1. Ignition switch |
ON | | 2. Throttle actuator power |
ON | Case 2 |
VPA2 voltage | Less than 4.84 V | |
Either of following conditions met: |
a or b | | a) VPA voltage - Learned VPA accelerator off position voltage |
0.04 V or more | | b) VPA2 voltage - Learned VPA2 accelerator off position voltage |
0.04 V or more | TYPICAL MALFUNCTION THRESHOLDS Case 1 |
Difference between VPA voltage and VPA2 voltage (learned value of accelerator off position) |
Less than 0.4 V, or more than 1.2 V | Case 2 |
(VPA voltage - Learned VPA accelerator off position voltage) - (VPA2 voltage - Learned VPA2 accelerator off position voltage) |
More than 0.165 V (varies with accelerator position) | CONFIRMATION DRIVING PATTERN
- Connect the Techstream to the DLC3.
- Turn the ignition switch to ON and turn the Techstream ON.
- Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).
- Turn the ignition switch off and wait for at least 30 seconds.
- Turn the ignition switch to ON and turn the Techstream on [A].
- Wait for 5 seconds after turning the ignition switch to ON.
- Operate the accelerator pedal in accordance with the following procedure [B].
- Enter the following menus: Powertrain / Engine and ECT / Data List / Accel Sens. No. 1 Volt %, and Accel Sens. No.2 Volt %.
- Slowly depress the accelerator pedal until Accel Sens. No.1 Volt % is
approximately 30% and Accel Sens. No.2 Volt % is approximately 46%, and
then slowly release the accelerator pedal.
- Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [C].
- Read the pending DTCs.
HINT:
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
- Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
- Input the DTC: P2121.
- Check the DTC judgment result.
|
Tester Display |
Description |
|
NORMAL |
- DTC judgment completed
- System normal
|
|
ABNORMAL |
- DTC judgment completed
- System abnormal
|
|
INCOMPLETE |
- DTC judgment not completed
- Perform driving pattern after confirming DTC enabling conditions
|
|
N/A |
- Unable to perform DTC judgment
- Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit
|
HINT:
- 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.
- If no pending DTC is output, perform a universal trip and check for permanent DTCs (See page
 ).
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 2 (main and sub) sensor circuits.
The ECM detects the abnormal signal voltage difference between the 2
sensor circuits and switches to fail-safe mode. If
the either of the 2 sensor circuits malfunctions, the ECM limits the
engine output. If both of the circuits malfunction, the ECM regards the
accelerator pedal as being released. 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 normal. WIRING DIAGRAM
Refer to DTC P2120 (See page
). CAUTION / NOTICE / HINT
HINT:
- This DTC relates to the Accelerator Pedal Position (APP) sensor.
- 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.
PROCEDURE |
1. | CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2121) |
(a) Connect the Techstream to the DLC3. (b) Turn the ignition switch to ON.
(c) Turn the Techstream on. (d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(e) 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 TECHSTREAM (ACCELERATOR PEDAL POSITIONSENSOR) |
 (a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON. (c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine and ECT / Data List / Accel Sensor Out No. 1 and Accel Sensor Out No. 2.
(e) Read the values displayed on the Techstream. Standard Voltage: |
Accelerator Pedal Operation |
Accel Sensor Out No. 1 | Accel Sensor Out 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 4.7 V |
| OK |
| CHECK FOR INTERMITTENT PROBLEMS |
|
NG | |
| |
| 3. |
REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY |
(a) Replace the accelerator pedal sensor assembly (See page
).
|
NEXT | |
| |
| 4. |
CHECK WHETHER DTC OUTPUT RECURS (DTC P2121) |
(a) Connect the Techstream to the DLC3. (b) Turn the ignition switch to ON.
(c) Turn the Techstream on. (d) Clear DTCs (See page
). (e) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.
(f) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(g) Read DTCs. Result |
Result | Proceed to | |
P2121 is output | A | |
No DTC is output | B |
| A |
| REPLACE ECM |
| B |
| END | | 
