Engine Control System (2AZ-FE) (Diagnostic Codes (P0500 - P2610) & Circuit Tests): Overview Toyota Matrix E140

DESCRIPTION

The speed sensors detect the wheel speed and send the appropriate signals to the skid control ECU. The skid control ECU converts these wheel speed signals into a 4-pulse signal and outputs it to the ECM via the combination meter. The ECM determines the vehicle speed based on the frequency of these pulse signals.

Scheme 68

MONITOR DESCRIPTION

Automatic Transaxle Models

The ECM assumes that the vehicle is being driven when the vehicle speed sensor signal is being transmitted by the combination meter. If there is no signal from the combination meter despite the ECM detecting the speed signal from the speed sensor, the ECM interprets this as a malfunction in the speed signal circuit. The ECM then illuminates the MIL and stores the DTC.

Manual Transaxle Models

The ECM assumes that the vehicle is being driven when the idle fuel-cut operation* is being executed. If there is no signal from the vehicle speed sensor despite this condition being met, the ECM interprets this as a malfunction in the speed signal circuit. The ECM then illuminates the MIL and stores the DTC.

*: Idle fuel-cut is executed when the throttle valve is fully closed and engine speed is over 2500 RPM.

The stop light switch is a duplex system that transmits two signals: STP and ST1-. These two signals are used by the ECM to monitor whether or not the brake system is working properly. If the signals, which indicate the brake pedal is being depressed and released, are detected simultaneously, the ECM interprets this as a malfunction in the stop light switch and sets the DTC.

HINT

The normal signal conditions are as shown in the table below.

1. [OFF] denotes ground potential.
2. [ON] denotes battery potential (+B).
3. On the Techstream, both the Data List items Stop Light Switch and ST1 are ON when the brake pedal is depressed because the ST1 indication characteristic is opposite to the Stop Light Switch indication.

Scheme 69

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON and turn the Techstream on.
3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure). Refer to «DTC CHECK / CLEAR»(ref-427310-S22296836352011101200000).
4. Turn the ignition switch off and wait for at least 30 seconds.
5. Turn the ignition switch to ON and turn the Techstream on [A].
6. Depress and release the brake pedal [B].
7. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
8. Input the DTC: P0504.
9. Check the DTC judgment result [C]. Techstream 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 UNKNOWN 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.
10. If the test result is UNKNOWN, enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
11. Read Pending DTCs. HINT: If a pending DTC is output, the system is malfunctioning.
12. If the test result is INCOMPLETE or UNKNOWN and no pending DTC is output, perform a universal trip and check for permanent DTCs. Refer to «DTC CHECK / CLEAR»(ref-427310-S22296836352011101200000). HINT: If a permanent DTC is output, the system is malfunctioning. If no permanent DTC is output, the system is normal.

Scheme 70

The idle speed is controlled by the electronic throttle control system. The electronic throttle control system is comprised of: 1) a one valve type throttle body; 2) a throttle actuator, which operates the throttle valve; 3) a throttle position sensor, which detects the opening angle of the throttle valve; 4) an accelerator pedal position sensor, which detects the accelerator pedal position; and 5) the ECM, which controls the electronic throttle control system. Based on the target idle speed, the ECM controls the throttle actuator to provide the proper throttle valve opening angle.

The ECM monitors the idling speed and idling air flow volume to conduct Idle Speed Control (ISC). The ECM determines that the ISC system is malfunctioning if either of the following conditions is met

1. The difference between the target engine idling speed and actual engine idling speed exceeds the threshold and the IAC flow rate learned value is stuck at the upper or lower limit for 5 seconds or more.
2. After driving at a vehicle speed of 6.25 mph (10 km/h) or more, the difference between the target and actual engine idling speed exceeds the threshold 5 times or more during a driving cycle, and then the system determines that the IAC flow rate learned value is stuck at the upper or lower limit, or that the IAC flow rate learned value has been changed by an amount that exceeds the threshold.

Scheme 71

This monitor will run when the engine is started at an engine coolant temperature of -10 to 50°C (14 to 122°F). The DTC can be set after the engine idles for 13 seconds (2 trip detection logic).

The DTC is designed to monitor the idle air control at cold start. When the engine is started at an engine coolant temperature of lower than 50°C (122°F), the ECM measures the accumulated mass air flow at idle. If it does not reach the specified level within 10 seconds, the ECM interprets this as a malfunction. The MIL is illuminated and a DTC is set when the malfunction is detected in consecutive driving cycles (2 trip detection logic).

The Electronic throttle control system controls the idle speed. The electronic throttle control system operates the throttle actuator to open and close the throttle valve, and adjusts the intake air amount to achieve the target idle speed.

Note. When the negative battery terminal is disconnected during inspections or repairs, the idle speed control learning values are cleared. This DTC cannot be set with the idle speed control learning values cleared.

HINT

The Idle speed control learning is performed when the engine is warmed up and has been idling for 5 minutes.

Scheme 72

This monitor will run when the engine is started at an engine coolant temperature of -10 to 50°C (14 to 122°F). The DTC is stored after the engine idles for 13 seconds (2 trip detection logic).

The DTC is designed to monitor the ignition timing at cold start. When the engine is started at an engine coolant temperature of below 50°C (122°F), the ECM checks the ignition timing during engine idling. If the ignition timing advances beyond the specified level within 10 seconds, the ECM interprets this as a malfunction. The MIL is illuminated and a DTC is stored when the malfunction is detected in consecutive driving cycles (2 trip detection logic).

Note. When the cable is disconnected from the negative (-) battery terminal during inspections or repairs, the idle speed control learned values are cleared. This DTC cannot be stored with the idle speed control learned values cleared.

HINT

The idle speed control learning is performed when the engine is warmed up and has been idling for 5 minutes.

Scheme 73

The battery supplies electricity to the ECM even when the ignition switch is off. This power allows the ECM to store data such as DTC history, freeze frame data and fuel trim values. If the battery voltage falls below a minimum level, the memory is cleared and the ECM determines that there is a malfunction in the power supply circuit. The next time the engine is started, the ECM illuminates the MIL and sets the DTC.

HINT

If DTC P0560 is set, the ECM does not store other DTCs or the data stored in the ECM may be partly erased.

The ECM continuously monitors its internal memory status. This self-check ensures that the ECM is functioning properly. It is diagnosed by internal "mirroring" of the main CPU and sub CPU to detect Random Access Memory (RAM) errors. If outputs from these CPUs are different and deviate from the standards, the ECM will illuminate the MIL and set the DTC immediately.

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 standards, the ECM will illuminate the MIL and set the DTC immediately.

The ECM continuously monitors its internal processors (CPUs) and Heated Oxygen (HO2) sensor transistors. This self-check ensures that the ECM is functioning properly.

The main CPU and sub CPU of the ECM communicate with each other. The main CPU monitors the communications and WDC pulses from the sub CPU. When the signal malfunctions below are detected, the DTC is stored.

The ECM monitors the input signals of the Accelerator Pedal Position (APP) sensor No. 1. When the input signals and control signals deviate, the DTC is stored.

The ECM monitors the input signals of the throttle position sensor No. 1 and stop light switch. When the ECM monitors the input signals of the throttle position sensor No. 1 and the STP signal of the stop light switch, if the input signals and control signals deviate, the DTC is stored.

While the engine is being cranked, battery voltage is applied to terminal STA of the ECM. If the ECM detects the starter (STA) signal while the vehicle is being driven, it determines that there is a malfunction in the STA circuit. The ECM then illuminates the MIL and sets the DTC.

This monitor runs when the vehicle is driven at 12.43 mph (20 km/h) for over 20 seconds.

The ECM monitors its internal operation and it stores this DTC when it detects an internal malfunction.

The ECM monitors its internal operation. If the internal operation is malfunctioning, the ECM illuminates the MIL and stores a DTC.

DTC P0630 is set when the Vehicle Identification Number (VIN) is not stored in the Engine Control Module (ECM) or the input VIN is not accurate. Input the VIN with the Techstream.

The ECM monitors the output voltage to the throttle actuator. This self-check ensures that the ECM is functioning properly. The output voltage is usually 0 V when the ignition switch is turned off. If the output voltage is higher than 7 volts when the ignition switch is turned off, the ECM will illuminate the MIL and set the DTC the next time the ignition switch is turned to ON.

The purpose of this circuit is to prevent the engine from stalling when brakes are suddenly applied while driving with the lock-up torque converter clutch on.

When the brake pedal is depressed, this switch sends a signal to the ECM. Then the ECM cancels the operation of the lock-up clutch while braking is in progress.

This DTC indicates that the stop light switch remains ON. When the stop light switch remains ON during "stop and go" driving, the ECM interprets this as a fault in the stop light switch, the MIL comes on and the ECM stores the DTC. The vehicle must stop (less than 1.86 mph [3 km/h]) and go (18.65 mph [30 km/h] or more) 5 times during 2 driving cycles, in order to detect a malfunction.

The ECM continuously monitors its main and sub CPUs for the cruise control. This self-check ensures that the ECM is functioning properly. If outputs from the CPUs are different and deviate from the standards, the ECM will illuminate the MIL and set the DTC immediately.

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

The opening angle of the throttle valve is detected by the throttle position sensor, which is mounted on the throttle body. 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 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 the current 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 sets a DTC.

1. Example: When the electrical current is less than 0.5 A and the throttle actuator duty ratio exceeds 80%, the ECM interprets this as the current being outside the standard range, and illuminates the MIL and sets a DTC. If the malfunction is not repaired successfully, the DTC can be set when the engine is quickly revved to a high RPM several times after the engine has idled for 5 seconds after starting the engine.

The throttle actuator is operated by the ECM, and opens and closes the throttle valve using an electric motor and gears. The opening angle of the throttle valve is detected by the throttle position sensor, which is mounted on the throttle body. 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 does not use a throttle cable.

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

If the malfunction is not repaired successfully, the DTC is stored when the accelerator pedal is fully depressed and released quickly (to fully open and close the throttle valve) after the engine is next started.

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. On the next restart, the ECM will allow the current to flow to the throttle actuator.

HINT

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

Scheme 74

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

When the power supply voltage (+BM) drops 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 sets the DTC.

If the malfunction is not repaired successfully, the DTC is set 5 seconds after the engine is next started.

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 sets the DTC.

If the malfunction is not repaired successfully, the DTC can be set when the accelerator pedal is quickly released (to close the throttle valve) after the engine speed reaches 5000 RPM by fully depressing the accelerator pedal (fully open the throttle valve).

HINT

1. This electronic throttle control system does not use a throttle cable.
2. These DTCs relate to the accelerator pedal position sensor.

The accelerator pedal position sensor is mounted on the accelerator pedal bracket and has 2 sensor circuits: VPA (main) and VPA2 (sub). This sensor is a non-contact type and uses Hall-effect elements in order to yield accurate signals even in extreme conditions. The voltage from this sensor, which is applied to terminals VPA and VPA2 of the ECM, varies between 0.5 V and 4.5 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 APP 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 75

HINT

When any of these DTCs are set, check the accelerator pedal position sensor voltage by entering the following menus: Powertrain / Engine and ECT / Data List / All Data / Accel Sensor Out No. 1 and Accel Sensor Out No. 2.

HINT

Accelerator pedal positions are expressed as voltages.

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

Example

When the output voltage of VPA drops below 0.4 V for more than 0.5 seconds when the accelerator pedal is fully depressed, DTC P2122 is set.

If the malfunction is not repaired successfully, a DTC is set 2 seconds after the engine is next started.

HINT

1. This DTC relates to the accelerator pedal position sensor.

Refer to DTC P2120. Refer to 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 the DTC is set.

HINT

Although the DTC titles say oxygen sensor, these DTCs relate to the air-fuel ratio sensor.

The air fuel ratio sensor generates a voltage* that corresponds to the actual air-fuel ratio. This sensor voltage is used to provide the ECM with feedback so that it can control the air-fuel ratio. The ECM determines the deviation from the stoichiometric air-fuel ratio level, and regulates the fuel injection duration. If the air fuel ratio sensor malfunctions, the ECM is unable to control the air-fuel ratio accurately.

The air fuel ratio sensor is a planar type with an integrated heater, which heats the solid electrolyte (zirconia element). This heater is controlled by the ECM. When the intake air volume is low (the exhaust gas temperature is low), current flows to the heater to heat the sensor, in order to facilitate accurate oxygen concentration detection. In addition, the sensor and heater portions are the narrow type. The heat generated by the heater is conducted to the solid electrolyte through the alumina, therefore the sensor activation is accelerated.

In order to obtain a high purification rate of the carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) components in the exhaust gas, a three-way catalytic converter is used. For the most efficient use of the three-way catalytic converter, the air-fuel ratio must be precisely controlled so that it is always close to the stoichiometric level.

*: Value changes inside the ECM. Since the air fuel ratio sensor uses a current output element, the current is converted into a voltage inside the ECM. Any measurements taken at the air fuel ratio sensor or ECM connectors will show a constant voltage.

Scheme 76

HINT

1. When any of these DTCs are set, check the air fuel ratio sensor voltage output by entering the following menus: Powertrain / Engine and ECT / Data List / All Data / AFS Voltage B1S1.
2. Short-term fuel trim values can also be read using the Techstream.
3. The ECM regulates the voltages at the A1A+ and A1A- terminals of the ECM to a constant level. Therefore, the air fuel ratio sensor voltage output cannot be confirmed without using the Techstream.
4. If a air fuel ratio sensor malfunction is detected, the ECM sets a DTC.

Sensor voltage detection monitor

Under the air-fuel ratio feedback control, if the air fuel ratio sensor voltage output indicates rich or lean for a certain period of time, the ECM determines that there is a malfunction in the air fuel ratio sensor. The ECM illuminates the MIL and sets a DTC.

Example

If the air fuel ratio sensor voltage output is less than 2.8 V (very rich condition) for 10 seconds, despite the heated oxygen sensor voltage output being less than 0.6 V, the ECM sets DTC P2196. Alternatively, if the air fuel ratio sensor voltage output is more than 3.8 V (very lean condition) for 10 seconds, despite the heated oxygen sensor voltage output being 0.15 V or more, DTC P2195 is set.

Sensor current detection monitor

A rich air-fuel mixture causes a low air fuel ratio sensor current, and a lean air-fuel mixture causes a high air fuel ratio sensor current. Therefore, the sensor output becomes low during acceleration, and it becomes high during deceleration with the throttle valve fully closed. The ECM monitors the air fuel ratio sensor current during fuel-cut and detects any abnormal current values.

If the air fuel ratio sensor output is 3.6 mA or more for more than 3 seconds of cumulative time, the ECM interprets this as a malfunction in the air fuel ratio sensor and sets DTC P2195 (high-side stuck). If the air fuel ratio sensor output is less than 1.0 mA for more than 3 seconds of cumulative time, the ECM sets DTC P2196 (low-side stuck).

Scheme 77

HINT

Although the DTC titles say oxygen sensor, these DTCs relate to the air fuel ratio sensor.

The air fuel ratio sensor, which is located between the exhaust manifold and catalyst, consists of alloyed metal elements and a heater.

Depending on the engine operating conditions, the heater heats the sensor elements to activate them. Battery voltage is applied to the heater, the sensor ground is controlled by the ECM using a duty ratio.

The sensor elements convert the oxygen concentration in the exhaust gas into voltage values to output. Based on the voltage, the ECM determines the air-fuel ratio and regulates the fuel injection volume depending on the air-fuel ratio and engine operating conditions. The voltage changes between 0.6 V and 4.5 V while the engine is running. If the air-fuel ratio is lean, which means the oxygen concentration in the exhaust gas is high, the voltage is high. If the air-fuel ratio is rich, which means the oxygen concentration in the exhaust gas is low, the voltage is low.

Scheme 78

These DTCs are output when there is an open or short in the air fuel ratio sensor circuit, or if air fuel ratio sensor output drops. To detect these problems, the voltage of the air fuel ratio sensor is monitored when turning the ignition switch to ON, and the admittance (admittance is an electrical term that indicates the ease of flow of current) is checked while driving. If the voltage of the air fuel ratio sensor is between 0.6 V and 4.5 V, it is considered normal. If the voltage is out of the specified range, or the admittance is less than the standard value, the ECM will determine that there is a malfunction in the air fuel ratio sensor. If the same malfunction is detected in next driving cycle, the MIL will be illuminated and a DTC will be stored.

The description can be found in the EVAP (Evaporative Emission) System. Refer to DESCRIPTION.

HINT

Unit expressions

1. [kPa-a (mmHg-a)] denotes absolute pressure.
2. [kPa-g (mmHg-g)] denotes gauge pressure (relative pressure).
3. On the Techstream, choose the unit of measurement according to the inspection procedure.

5 hours* after the ignition switch is turned off, the leak detection pump creates negative pressure (vacuum) in the EVAP system. The ECM monitors for leaks and actuator malfunctions based on the EVAP pressure.

HINT

*: If the engine coolant temperature is not below 35°C (95°F) 5 hours after the ignition switch is turned off, the monitor check starts 2 hours later. If it is still not below 35°C (95°F) 7 hours after the ignition switch is turned off, the monitor check starts 2.5 hours later.

*: If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.

Scheme 79

P2420: Vent valve stuck open (vent)

In operation C, the vent valve turns ON (closes) and the EVAP system pressure is then measured by the ECM using the canister pressure sensor to conduct an EVAP leak check. If the pressure does not increase when the vent valve is open, the ECM interprets this as the vent valve being stuck open. The ECM illuminates the MIL and sets the DTC.

Scheme 80

The soak timer operates after the ignition switch is turned off. When a certain amount of time has elapsed after turning the ignition switch off, the soak timer activates the ECM to perform malfunction checks which can only be performed after the engine is stopped. The soak timer is built into the ECM.

Scheme 81

1. While the engine is running, the ECM monitors the synchronization of the soak timer and the CPU clock. If these two are not synchronized, the ECM interprets this as a malfunction, illuminates the MIL and stores the DTC.
2. If the soak timer activates the ECM even though only a short amount of time has elapsed since the ignition switch was turned off, or if the soak timer does not activate the ECM even though a considerable amount of time has elapsed since the ignition switch was turned off, the ECM determines that the soak timer is malfunctioning, illuminates the MIL and stores a DTC the next time the ignition switch is turned ON.

HINT

Unit expressions

1. [kPa-a (mmHg-a)] denotes absolute pressure.
2. [kPa-g (mmHg-g)] denotes gauge pressure (relative pressure).
3. On the Techstream, choose the unit of measurement according to the inspection procedure.

Scheme 82

Scheme 83

Note. To check for leaks in the EVAP system, disconnect the air inlet vent hose and apply pressure from the atmospheric side of the canister.

While the engine is running, if a predetermined condition (closed-loop, etc.) is met, the purge VSV is opened by the ECM and stored fuel vapors in the canister are purged into the intake manifold. The ECM changes the duty cycle ratio of the purge VSV to control purge flow volume.

The purge flow volume is also determined by the intake manifold pressure. Atmospheric pressure is allowed into the canister through the vent valve to ensure that the purge flow is maintained when the negative pressure (vacuum) is applied to the canister.

The following two monitors run to confirm the appropriate EVAP system operation.

Scheme 84

Scheme 85

Scheme 86

1. Key-off monitor This monitor checks for EVAP (evaporative emission) system leaks and canister pump module malfunctions. The monitor starts 5 hours* after the ignition switch is turned off. At least 5 hours are required for the fuel to cool down to stabilize the EVAP pressure, thus making the EVAP system monitor more accurate. The leak detection pump creates negative pressure (vacuum) in the EVAP system and the pressure is measured. Finally, the ECM monitors for leaks from the EVAP system, and malfunctions in both the canister pump module and purge VSV, based on the EVAP pressure. HINT: *: If the engine coolant temperature is not below 35°C (95°F) 5 hours after the ignition switch is turned off, the monitor check starts 2 hours later. If it is still not below 35°C (95°F) 7 hours after the ignition switch is turned off, the monitor check starts 2.5 hours later.
2. Purge flow monitor The purge flow monitor consists of 2 monitors. The 1st monitor is conducted every time and the 2nd monitor is activated if necessary. The 1st monitor While the engine is running and the purge VSV (Vacuum Switching Valve) is ON (open), the ECM monitors the purge flow by measuring the EVAP pressure change. If negative pressure is not created, the ECM begins the 2nd monitor. The 2nd monitor The vent valve is turned ON (closed) and the EVAP pressure is measured. If the variation in the pressure is less than 0.4 kPa-g (3.0 mmHg-g), the ECM interprets this as the purge VSV being stuck closed, and illuminates the MIL and sets DTC P0441 (2 trip detection logic). Atmospheric pressure check: In order to ensure reliable malfunction detection, the variation between the atmospheric pressures, before and after the purge flow monitor is performed, is measured by the ECM. Component Operation Canister Contains activated charcoal to absorb evaporative emissions generated in fuel tank. Cut-off valve Located in fuel tank. Valve floats and closes when fuel tank 100% full. Purge VSV (Vacuum Switching Valve) Opens or closes line between canister and intake manifold. ECM uses purge VSV to control EVAP purge flow. In order to discharge EVAP absorbed by canister to intake manifold, ECM opens purge VSV. EVAP discharge volume to intake manifold controlled by purge VSV duty cycle ratio (current-carrying time) (Open: ON; Closed: OFF). Refueling valve Controls EVAP pressure from fuel tank to canister. Valve consists of diaphragm, spring and restrictor (diameter: 0.08 inch). When fuel vapor and pressure inside fuel tank increase, valve opens. While EVAP purged, valve closes and restrictor prevents large amount of vacuum from affecting pressure in fuel tank. Valve opened while refueling. Roll-over valve Located in fuel tank. Valve closed by its own weight when vehicle overturns to prevent fuel from spilling out. Soak timer Built into ECM. To ensure accurate EVAP monitor, measures 5 hours (+/-15 min.) after ignition switch turned off. This allows fuel to cool down, stabilizing EVAP pressure. When approximately 5 hours elapsed, ECM activates see scheme 3 Canister pump module Consists of (a) to (d) below. Canister pump module cannot be disassembled. (a) Vent valve Vents and closes EVAP system. When ECM turns valve ON, EVAP system closed. When ECM turns valve OFF, EVAP system vented. Negative pressure (vacuum) created in EVAP system to check for EVAP leaks by closing purge VSV, turning on vent valve (closed) and operating leak detection pump (Scheme 68) (b) Canister pressure sensor Indicates pressure as voltages. ECM supplies regulated 5 V to canister pressure sensor, and uses feedback from sensor to monitor EVAP system pressure see scheme 2 (c) Leak detection pump Creates negative pressure (vacuum) in EVAP system for leak check. (d) Reference orifice Has opening with 0.02 inch diameter. Vacuum produced through orifice by closing purge VSV, turning off vent valve and operating leak detection pump, to monitor reference pressure. Reference pressure indicates small leak of EVAP.

Scheme 87

When the ignition switch is turned to ON, the battery voltage is applied to the IGSW terminal of the ECM. The output signal from the MREL terminal of the ECM causes a current to flow to the EFI MAIN relay coil, closing the EFI MAIN relay contacts and supplying power to terminals +B and +B2 of the ECM.

Scheme 88

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Scheme 91

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Scheme 93

Scheme 94

1. INSPECT INTEGRATION RELAY (POWER SOURCE) Remove the integration relay from the engine room relay block. Disconnect the integration relay connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Condition Specified Condition 1E-1 - Body ground Always 11 to 14 V Reconnect the integration relay connector. Reinstall the integration relay. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY - BATTERY) OK: Go to next step
2. INSPECT FUSES (EFI MAIN, IG2, AND EFI NO. 1 FUSES) Remove the EFI MAIN fuse, IG2 fuse and EFI No. 1 fuse from the engine room relay block. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition EFI MAIN fuse Always Below 1 ohms IG2 fuse EFI No. 1 fuse Reinstall the fuses. NG --> REPLACE FUSE (EFI MAIN, IG2 OR EFI NO. 1 FUSE) OK: Go to next step
3. INSPECT INTEGRATION RELAY (EFI MAIN RELAY AND IG2 RELAY) Remove the integration relay from the engine room relay block. Disconnect the integration relay connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1E-1 - 1B-4 When battery voltage absent 10 kohms or higher When battery voltage applied to terminals 1B-2 and 1B-3 Below 1 ohms 1E-1 - 1A-4 When battery voltage absent 10 kohms or higher When battery voltage applied to terminals 1A-2 and 1A-3 Below 1 ohms Reconnect the integration relay connector. Reinstall the integration relay. NG --> See step 13 OK: Go to next step
4. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - ECM) Remove the integration relay from the engine room relay block. Disconnect the integration relay connector. Disconnect the ECM connector. Measure the resistance according to the value(s) in the table below. Standard Resistance (Check for Open) Tester Connection Condition Specified Condition A37-44 (MREL) - 1B-2 Always Below 1 ohms A37-2 (+B) - 1B-4 Always Below 1 ohms A37-1 (+B2) - 1B-4 Always Below 1 ohms Standard Resistance (Check for Short) Tester Connection Condition Specified Condition A37-44 (MREL) or 1B-2 - Body ground Always 10 kohms or higher A37-2 (+B) or 1B-4 - Body ground Always 10 kohms or higher A37-1 (+B2) or 1B-4 - Body ground Always 10 kohms or higher Reconnect the integration relay connector. Reinstall the integration relay. Reconnect the ECM connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY - ECM) OK: Go to next step
5. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - BODY GROUND) Remove the integration relay from the engine room relay block. Disconnect the integration relay connector. Measure the resistance according to the value(s) in the table below. Standard Resistance (Check for Open) Tester Connection Condition Specified Condition 1A-3 - Body ground Always Below 1 ohms 1B-3 - Body ground Always Below 1 ohms Reconnect the integration relay connector. Reinstall the integration relay. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY - BODY GROUND) OK: Go to next step
6. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) Disconnect the ECM connector. Measure the resistance according to the value(s) in the table below. Standard Resistance (Check for Open) Tester Connection Condition Specified Condition B29-104 (E1) - Body ground Always Below 1 ohms Reconnect the ECM connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - BODY GROUND) OK: Go to next step
7. INSPECT ECM (IGSW TERMINAL VOLTAGE) Disconnect the ECM connectors. Turn the ignition switch to ON. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition A37-28 (IGSW) - B29-104 (E1) Ignition switch ON 11 to 14 V Reconnect the ECM connectors. NG --> See step 8 OK --> See step 14
8. INSPECT FUSE (IGN FUSE) Remove the IGN fuse from the driver side junction block. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition IGN fuse Always Below 1 ohms Reinstall the IGN fuse. NG --> REPLACE FUSE (IGN FUSE) OK: Go to next step
9. CHECK HARNESS AND CONNECTOR (ECM - INTEGRATION RELAY) Remove the integration relay from the engine room relay block. Disconnect the integration relay connector. Disconnect the ECM connector. Measure the resistance according to the value(s) in the table below. Standard Resistance (Check for Open) Tester Connection Condition Specified Condition A37-28 (IGSW) - 1A-4 Always Below 1 ohms Standard Resistance (Check for Short) Tester Connection Condition Specified Condition A37-28 (IGSW) or 1A-4 - Body ground Always 10 kohms or higher Reconnect the integration relay connector. Reinstall the integration relay. Reconnect the ECM connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - INTEGRATION RELAY) OK: Go to next step
10. INSPECT FUSE (IG2 NO. 2 FUSE) Remove the IG2 No. 2 fuse from the engine room relay block. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition IG2 No. 2 fuse Always Below 1 ohms Reinstall the fuse. NG --> REPLACE FUSE (IG2 NO. 2 FUSE) OK: Go to next step
11. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - IGNITION SWITCH) Remove the integration relay from the engine room relay block. Disconnect the integration relay connector. Disconnect the ignition switch connector. Measure the resistance according to the value(s) in the table below. Standard Resistance (Check for Open) Tester Connection Condition Specified Condition 1A-2 - E5-6 (IG2) Always Below 1 ohms Standard Resistance (Check for Short) Tester Connection Condition Specified Condition 1A-2 or E5-6 (IG2) - Body ground Always 10 kohms or higher Reconnect the integration relay connector. Reinstall the integration relay. Reconnect the ignition switch connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY - IGNITION SWITCH) OK: Go to next step
12. INSPECT IGNITION SWITCH Inspect the ignition switch. Refer to «INSPECTION»(ref-427448-S37549428452011101200000). NG --> See step 15 OK --> REPAIR OR REPLACE HARNESS OR CONNECTOR (IGNITION SWITCH - BATTERY)
13. REPLACE INTEGRATION RELAY. Refer to «REMOVAL»(ref-427449-S20107372732011101200000)
14. REPLACE ECM. Refer to «REMOVAL»(ref-427449-S11002530612011101200000)
15. REPLACE IGNITION SWITCH. Refer to «REMOVAL»(ref-427448-S10497203402011101200000)

The ECM constantly generates 5 V power from the battery voltage supplied to the +B (BATT) terminal to operate the microprocessor. The ECM also provides this power to the sensors through the VC output circuit.

Scheme 95

When the VC circuit is short-circuited, the microprocessor in the ECM and sensors that are supplied with power through the VC circuit are inactivated because the power is not supplied from the VC circuit. Under this condition, the system does not start up and the MIL does not illuminate even if the system malfunctions.

HINT

Under normal conditions, the MIL is illuminated for several seconds when the ignition switch is first turned ON. The MIL goes off when the engine is started.

Scheme 96

Scheme 97

1. CHECK MIL Check that the Malfunction Indicator Lamp (MIL) lights up when turning the ignition switch to ON. OK MIL lights up NG --> See step 2 OK --> SYSTEM OK
2. CHECK COMMUNICATION BETWEEN TECHSTREAM AND ECM Connect the Techstream to the DLC3. Turn the ignition switch to ON. Turn the Techstream on. Check the communication between the Techstream and ECM. Result Result Proceed to Communication is not possible A Communication is possible B B --> See step 7 A: Go to next step
3. CHECK MIL (THROTTLE POSITION SENSOR) Disconnect the throttle body connector. Turn the ignition switch to ON. Check the MIL. Result Result Proceed to MIL does not illuminate A MIL illuminates B Reconnect the throttle body connector. B --> See step 8 A: Go to next step
4. CHECK MIL (ACCELERATOR PEDAL POSITION SENSOR) Disconnect the accelerator pedal position sensor connector. Turn the ignition switch to ON. Check the MIL. Result Result Proceed to MIL does not illuminate A MIL illuminates B Reconnect the accelerator pedal position sensor connector. B --> See step 9 A: Go to next step
5. CHECK MIL (CANISTER PUMP MODULE) Disconnect the canister pump module connector. Turn the ignition switch to ON. Check the MIL. Result Result Proceed to MIL does not illuminate A MIL illuminates (for 2WD) B MIL illuminates (for 4WD) C Reconnect the canister pump module connector. B --> See step 10 C --> See step 12 A: Go to next step
6. CHECK HARNESS AND CONNECTOR (VC CIRCUIT) Disconnect the throttle body connector. Disconnect the accelerator pedal position sensor connector. Disconnect the canister pump module connector. Disconnect the ECM connectors. Measure the resistance. Standard Resistance (Check for Short) Tester Connection Condition Specified Condition B29-67 (VCTA) - Body ground Always 10 kohms or higher A37-57 (VCPA) - Body ground Always 10 kohms or higher A37-58 (VCP2) - Body ground Always 10 kohms or higher B29-70 (VCPP) - Body ground Always 10 kohms or higher Reconnect the throttle body connector. Reconnect the accelerator pedal position sensor connector. Reconnect the canister pump module connector. Reconnect the ECM connectors. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 11
7. GO TO MIL CIRCUIT. Refer to «MIL Circuit»(ref-427447-S20384809572011101200000)
8. REPLACE THROTTLE BODY. Refer to «REMOVAL»(ref-427449-S05448414982011101200000)
9. REPLACE ACCELERATOR PEDAL ROD ASSEMBLY. Refer to «REMOVAL»(ref-427449-S15440121802011101200000)
10. REPLACE CANISTER. Refer to «REMOVAL»(ref-427455-S14895165742011101200000)
11. REPLACE ECM. Refer to «REMOVAL»(ref-427449-S11002530612011101200000)
12. REPLACE CANISTER. Refer to «REMOVAL»(ref-427455-S06584660472011101200000)

When the engine is cranked, the ST relay drive signal from the ignition switch is input into the STA terminal of the ECM, and the NE signal generated by the crankshaft position sensor is also input into the NE+ terminal. Thus, the ECM interprets that the engine is being cranked, and turns transistor Tr1 in the ECM internal circuit on. The current flows to the C/OPN (Circuit Opening) relay by turning Tr1 on. Then, the fuel pump operates.

While the NE signal is input into the ECM, and the engine is running, the ECM turns Tr1 on continuously.

Scheme 98

Scheme 99

Scheme 100

Scheme 101

1. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE FUEL PUMP/SPEED) Connect the Techstream to the DLC3. Turn the ignition switch to ON. Turn the Techstream on. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Fuel Pump/Speed. Check whether the fuel pump operating sound occurs when performing the Active Test using the Techstream. Result Result Proceed to Fuel pump operating sound does not occur A Fuel pump operating sound occurs B B --> See step 8 A: Go to next step
2. INSPECT DRIVER SIDE JUNCTION BLOCK (C/OPN RELAY INPUT VOLTAGE) Disconnect the driver side junction block connector. Measure the voltage between the terminal of the driver side junction block and the body ground when the ignition switch is turned to ON and off. Standard Voltage Tester Connection Switch Condition Specified Condition 2B-11 - Body ground Ignition switch off Below 1 V 2F-4 - Body ground 2B-11 - Body ground Ignition switch ON 11 to 14 V 2F-4 - Body ground Result Result Proceed to Outside standard range A Within standard range B Reconnect the driver side junction block connector. B --> See step 4 A: Go to next step
3. CHECK HARNESS AND CONNECTOR (DRIVER SIDE JUNCTION BLOCK - INTEGRATION RELAY) Remove the integration relay from the engine room relay block. Disconnect the integration relay connectors. Disconnect the driver side junction block connectors. Measure the resistance according to the value(s) in the table below. Standard Resistance (Check for Open) Tester Connection Condition Specified Condition 1A-4 - 2F-4 Always Below 1 ohms 1B-4 - 2B-11 Always Below 1 ohms Standard Resistance (Check for Short) Tester Connection Condition Specified Condition 1A-4 or 2F-4 - Body ground Always 10 kohms or higher 1B-4 or 2B-11 - Body ground Always 10 kohms or higher Reconnect the integration relay connectors. Reinstall the integration relay. Reconnect the driver side junction block connectors. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR (DRIVER SIDE JUNCTION BLOCK - INTEGRATION RELAY) OK --> See step 10
4. INSPECT DRIVER SIDE JUNCTION BLOCK (C/OPN RELAY) Disconnect the driver side junction block connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 2B-11 - 2A-8 When battery voltage absent 10 kohms or higher When battery voltage applied to terminals 2F-4 and 2B-10 Below 1 ohms Reconnect the driver side junction block connector. NG --> REPLACE DRIVER SIDE JUNCTION BLOCK OK: Go to next step
5. CHECK HARNESS AND CONNECTOR (C/OPN RELAY - ECM) Disconnect the ECM connector. Disconnect the driver side junction block connector. Measure the resistance according to the value(s) in the table below. Standard Resistance (Check for Open) Tester Connection Condition Specified Condition 2B-10 - A37-7 (FC) Always Below 1 ohms Standard Resistance (Check for Short) Tester Connection Condition Specified Condition 2B-10 or A37-7 (FC) - Body ground Always 10 kohms or higher Reconnect the driver side junction block connector. Reconnect the ECM connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR (C/OPN RELAY - ECM) OK: Go to next step
6. CHECK HARNESS AND CONNECTOR (DRIVER SIDE JUNCTION BLOCK - FUEL PUMP) Disconnect the driver side junction block connector. Disconnect the fuel pump connector. Measure the resistance according to the value(s) in the table below. Standard Resistance (Check for Open) Tester Connections Condition Specified Conditions 2A-8 - L13-4 (Fuel pump) Always Below 1 ohms Standard Resistance (Check for Short) Tester Connections Condition Specified Conditions 2A-8 or L13-4 (Fuel pump) - Body ground Always 10 kohms or higher Reconnect the fuel pump connector. Reconnect the driver side junction block connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR (DRIVER SIDE JUNCTION BLOCK - FUEL PUMP) OK: Go to next step
7. CHECK HARNESS AND CONNECTOR (FUEL PUMP - BODY GROUND) Disconnect the fuel pump connector. Measure the resistance according to the value(s) in the table below. Standard Resistance (Check for Open) Tester Connections Condition Specified Conditions L13-5 (Fuel pump) - Body ground Always Below 1 ohms Reconnect the fuel pump connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR (FUEL PUMP - BODY GROUND) OK: Go to next step
8. READ VALUE USING TECHSTREAM (STARTER SIGNAL) Connect the Techstream to the DLC3. Turn the ignition switch to ON. Turn the Techstream on. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Starter Signal. Check the result when the ignition switch is turned to ON and engine is started. OK Condition Starter Signal Ignition switch ON Close (Starter signal off) Engine started Open (Starter signal on) NG --> See step 12 OK: Go to next step
9. READ VALUE USING TECHSTREAM (ENGINE SPEED) Connect the Techstream to the DLC3. Turn the ignition switch to ON. Turn the Techstream on. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Engine Speed. Read the values displayed on the Techstream while cranking. OK Values are displayed continuously. NG --> See step 13 OK --> See step 11
10. GO TO ECM POWER SOURCE CIRCUIT. Refer to «ECM Power Source Circuit»(ref-427447-S31823850822011101200000)
11. REPLACE ECM. Refer to «REMOVAL»(ref-427449-S11002530612011101200000)
12. GO TO STARTER SIGNAL CIRCUIT. Refer to «Starter Signal Circuit»(ref-427447-S41067223092011101200000)
13. REPAIR OR REPLACE CRANKSHAFT POSITION SENSOR CIRCUIT. Refer to «INSPECTION PROCEDURE»(ref-427456-S07950040242011101200000)

The fuel injectors are located on the intake manifold. They inject fuel into the cylinders based on the signals from the ECM.

Scheme 102

Scheme 103

1. INSPECT FUEL INJECTOR (POWER SOURCE) Disconnect the fuel injector connectors. Turn the ignition switch to ON. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition B8-1 - Body ground Ignition switch ON 11 to 14 V B9-1 - Body ground Ignition switch ON 11 to 14 V B10-1 - Body ground Ignition switch ON 11 to 14 V B11-1 - Body ground Ignition switch ON 11 to 14 V Reconnect the fuel injector connectors. NG --> See step 6 OK: Go to next step
2. INSPECT FUEL INJECTOR (INJECTOR RESISTANCE) Inspect the fuel injector. Refer to «INSPECTION»(/toyota/matrix/e140-2008-2014/remont/fuel-system/#fuel-system-2az-fe-service-information) . NG --> See step 9 OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (FUEL INJECTOR - ECM) Disconnect the ECM connector. Disconnect the fuel injector connectors. Measure the resistance according to the value(s) in the table below. Standard Resistance (Check for Open) Tester Connection Condition Specified Condition B8-2 - B29-108 (#10) Always Below 1 ohms B9-2 - B29-107 (#20) Always Below 1 ohms B10-2 - B29-106 (#30) Always Below 1 ohms B11-2 - B29-105 (#40) Always Below 1 ohms Standard Resistance (Check for Short) Tester Connection Condition Specified Condition B8-2 or B29-108 (#10) - Body ground Always 10 kohms or higher B9-2 or B29-107 (#20) - Body ground Always 10 kohms or higher B10-2 or B29-106 (#30) - Body ground Always 10 kohms or higher B11-2 or B29-105 (#40) - Body ground Always 10 kohms or higher Reconnect the fuel injector connectors. Reconnect the ECM connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR (FUEL INJECTOR - ECM) OK: Go to next step
4. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) Disconnect the ECM connector. Measure the resistance according to the value(s) in the table below. Standard Resistance (Check for Open) Tester Connection Condition Specified Condition B29-45 (E01) - Body ground Always Below 1 ohms B29-44 (E02) - Body ground Always Below 1 ohms Reconnect the ECM connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - BODY GROUND) OK: Go to next step
5. INSPECT FUEL INJECTOR (INJECTION AND VOLUME) Check the fuel injector injection and volume. Refer to «INSPECTION»(/toyota/matrix/e140-2008-2014/remont/fuel-system/#fuel-system-2az-fe-service-information) . NG --> See step 9 OK --> See step 8
6. CHECK HARNESS AND CONNECTOR (FUEL INJECTOR - INTEGRATION RELAY) Disconnect the fuel injector connectors. Remove the integration relay from the engine room relay block. Disconnect the integration relay connector. Measure the resistance according to the value(s) in the table below. Standard Resistance (Check for Open) Tester Connection Condition Specified Condition B8-1 - 1A-4 Always Below 1 ohms B9-1 - 1A-4 Always Below 1 ohms B10-1 - 1A-4 Always Below 1 ohms B11-1 - 1A-4 Always Below 1 ohms Standard Resistance (Check for Short) Tester Connection Condition Specified Condition B8-1 or 1A-4 - Body ground Always 10 kohms or higher B9-1 or 1A-4 - Body ground Always 10 kohms or higher B10-1 or 1A-4 - Body ground Always 10 kohms or higher B11-1 or 1A-4 - Body ground Always 10 kohms or higher Reconnect the fuel injector connectors. Reconnect the integration relay connector. Reinstall the integration relay. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR (FUEL INJECTOR - INTEGRATION RELAY) OK --> See step 7
7. REPAIR OR REPLACE ECM POWER SOURCE CIRCUIT. Refer to «ECM Power Source Circuit»(ref-427447-S31823850822011101200000)
8. PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE»(ref-427310-S17806415292011101200000)
9. REPLACE FUEL INJECTOR. Refer to «REMOVAL»(/toyota/matrix/e140-2008-2014/remont/fuel-system/#fuel-system-2az-fe-service-information)

While the engine is being cranked, current flows from terminal ST1 of the ignition switch to the park/neutral position switch assembly (automatic transaxle models) or clutch pedal switch assembly (manual transaxle models) and also flows to terminal STA of the ECM (STA Signal).

When the vehicle is being driven with the accelerator pedal depressed, depressing the brake pedal without releasing the accelerator pedal will activate the brake override system to restrict driving torque. The conditions for activating the brake override system as well as the items that are controlled are explained below.

Scheme 104

Activation Conditions

1. Vehicle is running at or above the specified speed.
2. The accelerator pedal is depressed beyond a specified level, and then the brake pedal is depressed.

Note. The vehicle may not enter the brake override system control due to the relation of the accelerator pedal angle and the vehicle's speed.

Items Controlled

1. Driving torque is restricted.

HINT

During brake override system control, the value for the accelerator pedal angle (which is used for engine control) is forcibly reduced to a specified value. For this reason, the Data List value for Accelerator Position (applied to electronic throttle control) will be replaced with a specified value regardless of the actual accelerator pedal angle (Accel Sens. No. 1 Volt %, Accel Sens. No. 2 Volt %)

Deactivation Conditions

1. When the Stop Light Switch turns OFF or the actual accelerator pedal angle increases or decreases beyond the specified range.

The MIL (Malfunction Indicator Lamp) is used to indicate vehicle malfunction detections by the ECM. When the ignition switch is turned to ON, power is supplied to the MIL circuit, and the ECM provides the circuit ground which illuminates the MIL.

The MIL operation can be checked visually: When the ignition switch is first turned to ON, the MIL should illuminate and should then turn off. If the MIL remains illuminated or does not illuminate, conduct the following troubleshooting procedure using the Techstream.

Scheme 105

See also:
• ON-VEHICLE INSPECTION
• ON-VEHICLE INSPECTION - Step 2
• ON-VEHICLE INSPECTION - Step 2
• INSPECTION