P0120
2AZ-FXE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0120,P0122,P0123,P0220,P0222,P0223,P2135: Throttle / Pedal Position Sensor / Switch "A" Circuit Malfunction
DTC P0120 - Throttle / Pedal Position Sensor / Switch "A" Circuit Malfunction
DTC P0122 - Throttle / Pedal Position Sensor / Switch "A" Circuit Low Input
DTC P0123 - Throttle / Pedal Position Sensor / Switch "A" Circuit High Input
DTC P0220 - Throttle / Pedal Position Sensor / Switch "B" Circuit
DTC P0222 - Throttle / Pedal Position Sensor / Switch "B" Circuit Low Input
DTC P0223 - Throttle / Pedal Position Sensor / Switch "B" Circuit High Input
DTC P2135 - Throttle / Pedal Position Sensor / Switch "A" / "B" Voltage Correlation
CAUTION / NOTICE / HINT
HINT: These DTCs relate to the Throttle Position (TP) sensor.
DESCRIPTION
The TP sensor is mounted on the throttle body, and detects the opening angle of the throttle valve. This sensor is a non-contact type. 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 TP sensor has two sensor circuits which each transmits a signal, VTA1 and VTA2. 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 VTA terminals of the ECM (included in the hybrid vehicle control ECU).
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:
- When any of these DTCs are set, check the throttle valve opening angle by selecting the following menu items on the Techstream: Powertrain / Engine / Data List / ETCS / Throttle Position No. 1 and Throttle Position No. 2.
- Throttle Position No. 1 denotes the VTA signal, and Throttle Position No. 2 denotes the VTA2 signal.
Reference (Normal Condition):
MONITOR DESCRIPTION
The ECM (included in the hybrid vehicle control ECU) uses the Throttle Position (TP) sensor to monitor the throttle valve opening angle. There are several checks that the ECM performs to confirm 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.
If the malfunction is not repaired successfully, a DTC is set 10 seconds after the engine is next started.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
P0120:
P0122:
P0123:
P0220:
P0222:
P0223:
P2135 Case 1:
P2135 Case 2:
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 (included in the hybrid vehicle control ECU) enters fail-safe mode. During fail-safe mode, the ECM cuts the current to the throttle actuator off, and the throttle valve is returned to a 6.5° 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 gently, the vehicle can be driven slowly.
Fail-safe mode continues until a pass condition is detected, and the power switch is then turned off.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT: Read freeze frame data using the Techstream. The ECM (included in the hybrid vehicle control ECU) 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 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 tester on.
(c) Select the following menu items: Powertrain / Engine / Data List / ETCS / Throttle Position No. 1 and Throttle Position No. 2.
(d) Check the values displayed on the tester.
Result:
B -- CHECK WHETHER DTC OUTPUT RECURS (THROTTLE POSITION SENSOR DTCS)
A -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - HYBRID VEHICLE CONTROL ECU)
(a) Disconnect the C5 throttle body connector.
(b) Disconnect the C64 hybrid vehicle control ECU connector.
(c) Measure the resistance.
Standard resistance (Check for open):
Standard resistance (Check for short):
(d) Reconnect the throttle body connector.
(e) Reconnect the hybrid vehicle control ECU connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. INSPECT HYBRID VEHICLE CONTROL ECU (VC VOLTAGE)
(a) Disconnect the C5 throttle body connector.
(b) Turn the power switch on (IG).
(c) Measure the voltage between the terminals of the throttle body connector.
Standard voltage:
(d) Reconnect the throttle body connector.
NG -- REPLACE HYBRID VEHICLE CONTROL ECU
OK -- Continue to next step.
4. REPLACE THROTTLE BODY ASSEMBLY
(a) Replace the throttle body assembly 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 tester on.
(c) Clear the DTCs DTC Check / Clear.
(d) Put the engine in inspection mode Component Tests and General Diagnostics.
(e) Allow the engine to idle for 15 seconds or more.
(f) Select the following menu items: Powertrain / Engine / Trouble Code.
(g) Read the DTCs.
Result:
B -- SYSTEM IS OK
A -- REPLACE HYBRID VEHICLE CONTROL ECU