P0223
2UR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0120-P0123,P0220,P0222,P0223,P2135: Throttle / Pedal Position Sensor / Switch "A" Circuit Malfunction
DESCRIPTION
HINT
This ETCS (Electronic Throttle Control System) does not use a throttle cable.
The Throttle Position (TP) sensor is mounted on the throttle body, and detects the opening angle of the throttle valve. This sensor is a non-contact type, and 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 TP sensor has two sensor circuits, each of which transmits a signal, VTA and VTA2. VTA is used to detect the throttle valve angle and VTA2 is used to detect malfunctions in VTA. The sensor signal voltages vary between 0 V and 5 V in proportion to the throttle valve opening angle, and are transmitted to the VTA 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.
MONITOR DESCRIPTION
P0120, P0122, P0123, P0220, P0222, P0223, P2135
The ECM uses the Throttle Position (TP) sensor to monitor the throttle valve opening angle. There are several checks that the ECM performs to confirm the proper operation of the TP sensor.
- A specific voltage difference is expected between the sensor terminals, VTA and VTA2, for each throttle valve opening angle. If the difference between VTA and VTA2 is incorrect, the ECM interprets this as a malfunction in the sensor, and sets a DTC.
- VTA and VTA2 each have a specific voltage range. If VTA or VTA2 is outside the normal operating range, the ECM interprets this as a malfunction in the sensor, and sets a DTC.
- VTA and VTA2 should never be close to the same voltage level. If VTA is within 0.02 V of VTA2, the ECM determines that there is a short circuit in the sensor, and sets a DTC.
P0121
This sensor transmits 2 signals: VTA and VTA2. VTA is used to detect the throttle opening angle and VTA2 is used to detect malfunctions in VTA. The ECM performs several checks to confirm the proper operation of the throttle position sensor and VTA.
For each throttle opening angle, a specific voltage difference is expected between the outputs of VTA and VTA2. If the output voltage difference between the 2 signals deviates from the normal operating range, the ECM interprets this as a malfunction in the throttle position sensor. The ECM illuminates the MIL and sets a DTC.
If the malfunction is not repaired successfully, the DTC is stored 2 seconds after the engine is next started.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
P0120, P0122, P0123, P0220, P0222, P0223, P2135:
P0121:
TYPICAL MALFUNCTION THRESHOLDS
P0120:
P0121:
P0122:
P0123:
P0220:
P0222:
P0223:
P2135:
COMPONENT OPERATING RANGE
FAIL-SAFE
When any of these DTCs, as well as other DTCs relating to ETCS (Electronic Throttle Control System) malfunctions are set, 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° throttle 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 opening angle, to allow the vehicle to continue at a minimal speed. If the accelerator pedal is depressed firmly and gently, the vehicle can be driven slowly.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT
- If other DTCs relating to different systems that have terminal ETA as the ground terminal are output simultaneously, terminal ETA may have an open circuit.
- 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. READ VALUE USING TECHSTREAM (THROTTLE POSITION NO.1 AND THROTTLE POSITION NO.2)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG) and turn the Techstream on.
(c) Enter the following menus: Powertrain / Engine / Data List / ETCS / Throttle Position No.1 and Throttle Position No.2.
(d) While the accelerator pedal is released, read the values of Throttle Position No.1 and Throttle Position No.2.
(e) Start the engine.
(f) Read the values displayed on the Techstream.
Result
HINT
- DTC P0121 is stored when the voltages output from VTA and VTA2 are not consistent with the characteristics of the sensor. Therefore, check the freeze frame data when this DTC is output. Use the following formula to confirm relative fluctuations in voltage.
Characteristics of sensor output
* VTA2 x 0.8 is approximately equal to VTA + 1.11 V
* VTA: Throttle Position No. 1
* VTA2: Throttle Position No. 2
- If DTC P0121 is output, proceed to "CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - ECM)".
B -- CHECK WHETHER DTC OUTPUT RECURS (THROTTLE POSITION SENSOR DTCS)
A -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - ECM)
(a) Disconnect the E21 throttle body connector.
(b) Disconnect the E2 ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):
Standard resistance (Check for short):
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. INSPECT ECM (VCTA VOLTAGE)
(a) Disconnect the E21 throttle body connector.
(b) Turn the power switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:
NG -- REPLACE ECM Removal
OK -- Continue to next step.
4. REPLACE THROTTLE BODY
(a) Replace the throttle body Removal.
NEXT -- Continue to next step.
5. CHECK WHETHER DTC OUTPUT RECURS (THROTTLE POSITION SENSOR DTCS)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG) and turn the Techstream ON.
(c) Clear DTCs DTC Check / Clear.
(d) Put the engine in inspection mode Inspection Mode Procedure.
(e) Allow the engine to idle for 15 seconds or more.
(f) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(g) Read DTCs.
Result
B -- END
A -- REPLACE ECM Removal