Engine Control System (Diagnostic Codes (P106A - P2125)) (2ZR-FAE): Overview Toyota Corolla XI

DESCRIPTION

This DTC is designed to detect a deviation in the output characteristics of a pressure sensor.

MONITOR DESCRIPTION

The pressure of the canister pressure sensor and manifold absolute pressure sensor is monitored 50 minutes after the ignition switch is turned off. If there is a difference in the pressures, the ECM illuminates the MIL and stores this DTC.

HINT

Correct judgment may not be possible when the altitude is 13124 ft. (4000 m) or more.

The VALVEMATIC system is able to continuously change the valve lift amount and valve timing. The VALVEMATIC system cooperates with the VVT-i to adjust the valve lift amount and valve timing optimally according to driving conditions. The ECM calculates the target intake air amount based on the amount the accelerator pedal is depressed and the engine speed to determine the valve lift amount (duration), valve timing and throttle valve opening angle. The continuously variable valve lift controller assembly operates the actuator to adjust the duration to the duration requested by the ECM via CAN communication. The actual operating conditions are monitored by the sensors in the continuously variable valve lift controller assembly, which sends the actual duration value to the ECM. The continuously variable valve lift controller assembly consists of the EDU, actuator, differential roller gear, angle sensor and position sensor.

Scheme 262

Perform the following procedures to confirm that the VALVEMATIC system is operating normally.

1. Connect the Techstream to the DLC3.
2. Start the engine.
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the VALVEMATIC(ENG ON) / Gas Valve Control / VALVEMATIC Current Angle and VALVEMATIC Target Angle. NOTE: Make sure the following conditions are met when performing the Active Test. The engine is running. The engine coolant temperature is 40°C (104°F) or higher. The vehicle is stationary. The shift lever is in P or N. Result The "VALVEMATIC Current Angle" follows the "VALVEMATIC Target Angle".

HINT

Perform a simulation test by referring to the engine coolant temperature and intake air temperature recorded in the freeze frame data.

When the Active Test results are abnormal, remove the continuously variable valve lift controller assembly from the camshaft housing sub-assembly and perform the "Activate the VALVEMATIC(ENG OFF)" Active Test with the continuously variable valve lift controller assembly removed to determine whether the problem is with the continuously variable valve lift controller assembly or camshaft housing sub-assembly.

The ECM monitors the continuously variable valve lift controller assembly and detects malfunctions. If the actual duration differs from the requested duration by 14.5°CA or higher, the ECM illuminates the MIL and stores a DTC. DTC P10A0 is usually only stored if a mulfunction is detected during cold engine start. DTC P1055 is stored if a malfunction is detected in any other situation.

P1603

After starting the engine, this DTC is stored when the engine stops without the ignition switch being operated.

Using the Techstream, the conditions present when the DTC was stored can be confirmed by referring to the freeze frame data. Freeze frame data records engine conditions when a malfunction occurs. This information can be useful when troubleshooting.

It is necessary to check if the vehicle has run out of fuel before performing troubleshooting, as this DTC is also stored when the engine stalls due to running out of fuel.

P1605

This DTC is stored if the engine speed drops below the set speed.

Using the Techstream, the conditions present when the DTC was stored can be confirmed by referring to the freeze frame data. Freeze frame data records engine conditions when a malfunction occurs. This information can be useful when troubleshooting.

It is necessary to check if the vehicle ran out of fuel before performing troubleshooting, as this DTC is also stored when idling is unstable due to running out of fuel.

This DTC is stored when the engine does not start even though the STA signal is input or when the engine takes a long time to start, and when the engine speed is low or the engine stalls just after the engine starts.

Using the Techstream, the conditions present when the DTC was stored can be confirmed by referring to the freeze frame data. Freeze frame data records engine conditions when a malfunction occurs. This information can be useful when troubleshooting.

It is necessary to check if the vehicle ran out of fuel before performing troubleshooting, as this DTC is also stored when there is engine starting trouble due to running out of fuel.

Scheme 263

The ECM continuously monitors its main and sub CPUs. This self-check ensures that the ECM is functioning properly. If outputs from the CPUs are different and deviate from the standard, the ECM will illuminate the MIL and store this DTC.

The throttle actuator is operated by the ECM and opens and closes the throttle valve using gears.

The opening angle of the throttle valve is detected by the throttle position sensor, which is mounted on the throttle body assembly. The throttle position sensor provides feedback to the ECM. This feedback allows the ECM to appropriately control the throttle actuator and monitor the throttle opening angle as the ECM responds to driver inputs.

HINT

This Electronic Throttle Control System (ETCS) does not use a throttle cable.

The ECM monitors the electrical current through the electronic actuator, and detects malfunctions and open circuits in the throttle actuator based on this value. If the current is outside the standard range, the ECM determines that there is a malfunction in the throttle actuator. In addition, if the throttle valve does not function properly (for example, stuck on), the ECM determines that there is a malfunction. The ECM then illuminates the MIL and stores a DTC.

The idle speed is controlled by the Electronic Throttle Control System (ETCS). The ETCS is comprised of a throttle actuator, which operates the throttle valve, and a throttle position sensor, which detects the opening amount of the throttle valve. The ECM controls the throttle actuator to adjust the throttle valve opening amount so that the idle speed is maintained at the target idle speed.

HINT

1. The ISC learned value is the calculated intake air amount corresponding to the throttle opening amount necessary to maintain the idling speed.
2. This malfunction is only detected once per trip. After it has been detected once, the system will not monitor for the malfunction for the rest of the trip.
3. The system uses the throttle body assembly and mass air flow meter sub-assembly to detect this malfunction.

If there are deposits in the throttle valve, a decrease in the ISC flow rate may cause engine stall or unstable idling. Therefore, the necessary ISC flow rate for idling is maintained using the ISC learned value and feedback. The ECM stores this DTC if the ISC learned value approaches its limit. The ECM begins monitoring for the DTC detection conditions when the following preconditions are met

1) The mass air flow meter sub-assembly is normal.

2) Atmospheric pressure is 85 kPa(abs) [637.6 mmHg(abs)] or higher.

3) The vehicle has been driven at a speed of 30 km/h (18.7 mph) or more at least once.

4) The engine coolant temperature is 45°C (113°F) or less at engine start, the engine is warmed up and conditions for ISC learning are met, or the ignition switch has been turned to ON (including when the engine is running) for 1 hour or more, the engine is warmed up and conditions for ISC learning are met.

The throttle actuator is operated by the ECM, and opens and closes the throttle valve using gears. The opening angle of the throttle valve is detected by the throttle position sensor, which is mounted on the throttle body assembly. The throttle position sensor provides feedback to the ECM. This feedback allows the ECM to appropriately control the throttle actuator and monitor the throttle opening angle as the ECM responds to driver inputs.

HINT

This Electronic Throttle Control System (ETCS) does not use a throttle cable.

The ECM determines that there is a malfunction in the ETCS when the throttle valve remains at a fixed angle despite a high drive current from the ECM. The ECM illuminates the MIL and stores a DTC.

The electronic throttle control system has a dedicated power supply circuit. The voltage (+BM) is monitored and when it is low (less than 4 V), the ECM determines that there is a malfunction in the electronic throttle control system and cuts off the current to the throttle actuator.

When the voltage becomes unstable, the electronic throttle control system itself becomes unstable. For this reason, when the voltage is low, the current to the throttle actuator is cut. If repairs are made and the system returns to normal, turn the ignition switch off. The ECM then allows the current to flow to the throttle actuator so that it can be restarted.

HINT

The electronic throttle control system does not use a throttle cable.

Scheme 264

The ECM monitors the battery supply voltage applied to the throttle actuator.

When the power supply voltage (+BM) is less than 4 V for 0.8 seconds or more, the ECM interprets this as an open in the power supply circuit (+BM). The ECM illuminates the MIL and stores this DTC.

The electronic throttle control system is composed of the throttle actuator, throttle position sensor, accelerator pedal position sensor, and ECM. The ECM operates the throttle actuator to regulate the throttle valve in response to driver inputs. The throttle position sensor detects the opening angle of the throttle valve, and provides the ECM with feedback so that the throttle valve can be appropriately controlled by the ECM.

The ECM determines the actual opening angle of the throttle valve from the throttle position sensor signal. The actual opening angle is compared to the target opening angle commanded by the ECM. If the difference between these two values is outside the standard range, the ECM interprets this as a malfunction in the electronic throttle control system. The ECM then illuminates the MIL and stores this DTC.

HINT

1. This Electronic Throttle Control System (ETCS) does not use a throttle cable.
2. These DTCs relate to the accelerator pedal position sensor.

The accelerator pedal position sensor is built into the accelerator pedal sensor assembly and has 2 sensor circuits: VPA (main) and VPA2 (sub). This sensor is a non-contact type sensor 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 voltage, which is applied to terminals VPA and VPA2 of the ECM, varies between 0.5 V and 4.75 V in proportion to the operating angle of the accelerator pedal (throttle valve). A signal from VPA indicates the actual accelerator pedal opening angle (throttle valve opening angle) and is used for engine control. A signal from VPA2 conveys the status of the VPA circuit and is used to check the accelerator pedal position sensor itself.

The ECM monitors the actual accelerator pedal opening angle (throttle valve opening angle) through the signals from VPA and VPA2, and controls the throttle actuator according to these signals.

Scheme 265

HINT

When any of these DTCs are output, check the accelerator pedal position sensor voltage using the Techstream. Enter the following menus: Powertrain / Engine and ECT / Data List / Gas Throttle / Accel Sensor Out No. 1 and Accel Sensor Out No. 2.

HINT

Accelerator pedal positions are expressed as voltages.

When either output voltage of VPA or VPA2 deviates from the standard range, or the difference between the output voltages of the 2 sensor circuits is more than the threshold, the ECM determines that there is a malfunction in the accelerator pedal position sensor. The ECM then illuminates the MIL and stores a DTC.

Example

When the output voltage of VPA is 0.4 V or less for 0.5 seconds or more when the accelerator pedal is fully depressed, DTC P2122 is stored.

See also:
• ON-VEHICLE INSPECTION [08/2013 - ]
• ON-VEHICLE INSPECTION [08/2013 - ]
• ON-VEHICLE INSPECTION [08/2013 - ]
• PROCEDURE - Step 2