DESCRIPTION
The throttle position sensor is built into the throttle body with motor assembly and detects the opening angle of the throttle valve. This sensor is a non-contact type sensor. It uses Hall-effect elements in order to yield accurate signals even in extreme driving conditions, such as at high speeds as well as very low speeds.
The throttle position sensor has 2 sensor circuits, VTA1 and VTA2, each of which transmits a signal. VTA1 is used to detect the throttle valve angle and VTA2 is used to detect malfunctions in VTA1. The sensor signal voltages vary between 0 V and 5 V in proportion to the throttle valve opening angle, and are transmitted to the VTA1 and VTA2 terminals of the ECM.
As the valve closes, the sensor output voltage decreases and as the valve opens, the sensor output voltage increases. The ECM calculates the throttle valve opening angle according to these signals and controls the throttle actuator in response to driver inputs. These signals are also used in calculations such as air fuel ratio correction, power increase correction and fuel-cut control.
HINT:
Reference (Normal Condition):
When Accelerator Pedal Fully Released | When Accelerator Pedal Fully Depressed (Engine Running) | ||
---|---|---|---|
Throttle Position Sensor No.1 Voltage (VTA1) | Throttle Position Sensor No.2 Voltage (VTA2) | Throttle Position Sensor No.1 Voltage (VTA1) | Throttle Position Sensor No.2 Voltage (VTA2) |
0.6 to 1.1 V | 2.1 to 3.1 V | 3.2 to 4.8 V (Not fail-safe) | 4.6 to 4.98 V (Not fail-safe) |
DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Note |
---|---|---|---|---|---|
P012011 | Throttle / Pedal Position Sensor / Switch "A" Circuit Short to Ground | The output voltage of VTA1 is below 0.56 V for 2 seconds or more (1 trip detection logic). |
| Comes on | SAE: P0122 |
MONITOR DESCRIPTION
The ECM uses the throttle position sensor to monitor the throttle valve opening angle. If the VTA1 terminal voltage is less than the threshold, the ECM will illuminate the MIL and store this DTC.
MONITOR STRATEGY
Frequency of Operation | Continuous |
CONFIRMATION DRIVING PATTERN
HINT:
GTS Display | Description |
---|---|
NORMAL |
|
ABNORMAL |
|
INCOMPLETE |
|
HINT:
FAIL-SAFE
When this DTC is stored, the ECM enters fail-safe mode. During fail-safe mode, the ECM cuts the current to the throttle actuator, and the throttle valve is returned to a 7.5° throttle valve opening angle by the return spring. The ECM then adjusts the engine output by controlling the fuel injection (intermittent fuel-cut) and ignition timing, in accordance with the accelerator pedal angle, to allow the vehicle to continue running at a minimal speed. If the accelerator pedal is depressed firmly and gently, the vehicle can be driven slowly.
Fail-safe mode continues until a pass condition is detected, and the ignition switch is turned off.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
HINT:
Read Freeze Frame Data using the GTS. The ECM records vehicle and driving condition information as Freeze Frame Data the moment a DTC is stored. 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. | READ VALUE USING GTS (THROTTLE POSITION SENSOR NO.1 VOLTAGE) |
(a) Read the values displayed on the GTS.
Powertrain > Engine > Data List Tester Display |
---|
Throttle Position Sensor No.1 Voltage |
(b) Disconnect the throttle body with motor assembly connector.
(c) Compare the value of the Data List item Throttle Position Sensor No.1 Voltage after disconnecting the throttle body with motor assembly connector to the value when the connector was connected.
Result | Proceed to |
---|---|
Changes from below 0.56 V to higher than 4.535 V | A |
Does not change from below 0.56 V | B |
A | REPLACE THROTTLE BODY WITH MOTOR ASSEMBLY |
|
2. | CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - ECM) |
(a) Disconnect the throttle body with motor assembly connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection | Condition | Specified Condition |
---|---|---|
D19-5(VC) - D104-109(VCTA) | Always | Below 1 Ω |
D19-6(VTA) or D104-108(VTA1) - Body ground | Always | 10 kΩ or higher |
OK | REPLACE ECM |
NG | REPAIR OR REPLACE HARNESS OR CONNECTOR |
The front and side supplemental restraint systems (SRS) include different types of air bags. Please verify the different types of air bags which are equipped on your vehicle by locating the “SRS AIRBAG” location indicators. These indicators are visible in the area where the air bags are installed.
The air bags are installed in the following locations:
The steering wheel hub (driver air bag) The front passenger dashboard (front passenger air bag) The outboard sides of the front seatbacks (side air bags) The front and rear window pillars, and the roof edge along both sides (curtain air bags)