Engine Control System (Diagnostic Codes (P1604-P2610) & Circuit Tests)): Overview Lexus GX J150

DESCRIPTION

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 44

Scheme 45

Scheme 46

Scheme 47

1. Reference waveforms showing a normal cold engine start
2. Reference waveforms showing a normal warm engine start
3. Reference values when there is an air leak in the intake system during starting difficulty HINT: The engine started momentarily but stalled immediately after starting due to an air leak.

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 a DTC immediately.

Refer to DTC P0412. Refer to DESCRIPTION .

MONITOR DESCRIPTION

This DTC indicates an open or short circuit in the circuit containing the air pump of the secondary air injection system. The air injection control driver performs diagnosis of the air pump, air switching valve and itself, and sends the results of this diagnosis to the ECM as a duty signal. When the ECM receives a signal indicating a malfunction in the air pump, air switching valve or air injection control driver, it immediately illuminates the MIL and stores a 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. 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 ETCS (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 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, if it is stuck on), the ECM determines that there is a malfunction. The ECM then illuminates the MIL and stores a DTC.

Example

When the electrical current is less than 0.5 A and the throttle actuator duty ratio is 80% or more, the ECM interprets this as the current being outside the standard range, illuminates the MIL and stores a DTC.

If the malfunction is not repaired successfully, a DTC is stored when the engine is quickly revved to a high engine speed several times after the engine is started and has idled for 5 seconds.

The idling 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 idling speed is maintained at the target idling 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 assembly to detect this malfunction.

If there are deposits in the throttle valve, a decrease in the ISC flow rate may cause engine stall an 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 manifold absolute pressure sensor is normal; 2) atmospheric pressure is 85 kPa (638 mmHg) or higher; 3) the vehicle has been driven at a speed of 30 km/h (18.65 mph) or more at least once; and 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 engine switch has been turned on (IG) (include engine 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. The throttle position sensor provides feedback to the ECM so that the ECM can control the throttle actuator (throttle valve) appropriately in response to driver inputs.

HINT

This ETCS (Electronic Throttle Control System) 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.

If the malfunction is not repaired successfully, a 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 ETCS (Electronic Throttle Control System) has a dedicated power supply circuit. The voltage (+BM) is monitored and when it is low (below 4 V), the ECM determines that there is a malfunction in the ETCS and cuts off the current to the throttle actuator.

When the voltage becomes unstable, the ETCS 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 engine switch off. The ECM then allows the current to flow to the throttle actuator so that it can be restarted.

HINT

The ETCS does not use a throttle cable.

Scheme 48

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

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

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

The Electronic Throttle Control System (ETCS) 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 calculated by the ECM. If the difference between these two values is outside the standard range, the ECM interprets this as a malfunction in the ETCS. The ECM then illuminates the MIL and stores the DTC.

If the malfunction is not repaired successfully, the DTC is stored when the accelerator pedal is quickly released (to close the throttle valve) after the engine speed reaches 5000 rpm by the accelerator pedal being fully depressed (fully opening the throttle valve).

The accelerator pedal position sensor assembly 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 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 4.5 V in proportion to the position of the accelerator pedal (throttle valve). The signal from VPA indicates the actual accelerator pedal position (throttle valve opening angle) and is used for engine control. The 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 position (throttle valve opening angle) through the signals from VPA and VPA2, and controls the throttle actuator according to these signals.

HINT

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

Scheme 49

HINT

When any of these DTCs are stored, 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 the output voltage of either 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 accelerator pedal position sensor. The ECM then illuminates the MIL and stores 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 stored.

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

HINT

Refer to DTC P2120. Refer to DESCRIPTION .

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 stores the DTC.

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 and regulates the fuel injection time. If the air fuel ratio sensor malfunctions, the ECM is unable to control the air-fuel ratio accurately.

The air fuel ratio sensor is of the planar type and is integrated with a 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), a current flows through the heater to heat the sensor in order to facilitate accurate air-fuel ratio 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, thereby accelerating the sensor activation.

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 (TWC) is used. For the most efficient use of the Three-Way Catalytic Converter (TWC), the air-fuel ratio must be precisely controlled so that it is always close to the stoichiometric level.

*: The value changes inside the ECM. Since the air fuel ratio sensor is 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 50

HINT

1. DTCs P2195 and P2196 indicate malfunctions related to the bank 1 air fuel ratio sensor circuit.
2. DTCs P2197 and P2198 indicate malfunctions related to the bank 2 air fuel ratio sensor circuit.
3. When any of these DTCs is stored, check the air fuel ratio sensor output voltage by entering the following menus: Powertrain / Engine and ECT / Data List / All Data / AFS Voltage B1S1 or AFS Voltage B2S1.
4. Short-term fuel trim values can also be read using the Techstream.
5. The ECM maintains the voltages at the A1A+ and A1A-, and A2A+ and A2A- terminals of the ECM at a constant level. Therefore, the air fuel ratio sensor output voltage cannot be confirmed without using the Techstream.
6. If the air fuel ratio sensor is malfunctioning, the ECM stores DTC P2195, P2196, P2197 or P2198.

Sensor voltage detection monitor

Under air-fuel ratio feedback control, If the air fuel ratio sensor output voltage is below 2.8 V (very rich condition) for 5 seconds despite the rear heated oxygen sensor output voltage being below 0.59 V, the ECM stores DTC P2196 or P2198. Alternatively, if the air fuel ratio sensor output voltage is higher than 3.8 V (very lean condition) for 5 seconds despite the rear heated oxygen sensor output voltage being 0.21 V or higher, DTC P2195 or P2197 is stored.

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 higher for more than 3 seconds of cumulative time, the ECM interprets this as a malfunction in the air fuel ratio sensor and stores DTC P2195 or P2197 (stuck on high side). If the air fuel ratio sensor output is below 1.4 mA for more than 3 seconds of cumulative time, the ECM stores DTC P2196 or P2198 (stuck on low side).

Scheme 51

Refer to DTC P2195. Refer to DESCRIPTION .

HINT

1. DTCs P2237, P2238, P2239, P2252 and P2253 indicate malfunctions related to the bank 1 air fuel ratio sensor circuit.
2. DTCs P2240, P2241, P2242, P2255 and P2256 indicate malfunctions related to the bank 2 air fuel ratio sensor circuit.

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 engine switch on (IG), 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 outside of the specified range, or the admittance is below 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 the next driving cycle, the MIL is illuminated and a DTC is stored.

The air fuel ratio sensor varies its output voltage in proportion to the air-fuel ratio. If the air fuel ratio sensor impedance (alternating current resistance) or output voltage deviates greatly from the standard range, the ECM determines that there is an open or short in the air fuel ratio sensor circuit.

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

5 hours* after the engine 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 engine 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 engine 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 52

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 stores the DTC.

Scheme 53

Refer to DTC P0412. Refer to DESCRIPTION .

Refer to DTC P0416. Refer to DESCRIPTION .

Scheme 54

The ECM monitors the pressure in the secondary air passage using the pressure sensor located on the air switching valve in the secondary air injection system. Using this pressure value, the ECM determines whether the secondary air injection system is malfunctioning or not.

If there is a defect in the sensor or the sensor circuit, the voltage level deviates from the normal operating range. The ECM interprets this deviation as a malfunction in the pressure sensor or circuit and stores a DTC.

Refer to DTC P0412. Refer to DESCRIPTION .

HINT

Air switching valve normal operation

When the air switching valve is open, exhaust gas pulsation occurs in the secondary air passage.

When the air switching valve is closed, exhaust gas pulsation does not occur in the secondary air passage.

DTCs P2440 and P2442 indicate that the air switching valve is stuck open. DTCs P2441 and P2443 indicate that the air switching valve is stuck closed. The ECM performs diagnosis of the secondary air injection system based on the pressure pulsation when the system is not operating. If a malfunction is detected, the ECM illuminates the MIL and stores a DTC.

Refer to P0412. Refer to DESCRIPTION .

The ECM monitors the pressure in the secondary air passage using the pressure sensor located on the air switching valve of the secondary air injection system. The sensor measures the pressure in the secondary air passage and transmits a signal to the ECM.

If either of the following conditions occurs, the ECM interprets it as a malfunction of the secondary air injection system, and illuminates the MIL and stores a DTC

1. The pressure indicated by the pressure sensor does not reach threshold levels despite the ECM turning on the air pump.
2. The pressure indicated by the pressure sensor exceeds threshold levels despite the ECM turning off the air pump.

Example

1. DTC P2444 mainly indicates a malfunction in which the air pump is stuck on.
2. DTC P2445 and P2447 mainly indicate a malfunction in which the air pump is stuck off.

The soak timer operates after the engine switch is turned off. When a certain amount of time has elapsed after turning the engine 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 55

1. While the engine is running, the ECM monitors the synchronization of the soak timer and 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 engine 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 engine switch was turned off, the ECM determines that the soak timer is malfunctioning, illuminates the MIL and stores a DTC the next time the engine switch is turned on (IG).

When the engine switch is turned on (IG), 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 coil of the No. 1 integration relay (EFI relay), closing the contacts and supplying power to terminals +B and +B2 of the ECM.

Scheme 56

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

Scheme 57

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 engine switch is first turned on (IG). The MIL goes off when the engine is started.

Scheme 58

Scheme 59

Scheme 60

Scheme 61

1. CHECK MIL Check that the Malfunction Indicator Lamp (MIL) lights up when the engine switch is turned on (IG). OK MIL lights up. NG --> See step 2 OK --> See step 17
2. CHECK COMMUNICATION BETWEEN TECHSTREAM AND ECM Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Check the communication between the Techstream and ECM. RESULT Result Proceed to Communication is possible A Communication is not possible B A --> See step 18 B: Go to next step
3. CHECK MIL (THROTTLE POSITION SENSOR) Disconnect the throttle body connector. Turn the engine switch on (IG). Check the MIL. RESULT Result Proceed to MIL illuminates A MIL does not illuminate B A --> See step 19 B: Go to next step
4. CHECK MIL (ACCELERATOR PEDAL POSITION SENSOR) Disconnect the accelerator pedal position sensor connector. Turn the engine switch on (IG). Check the MIL. RESULT Result Proceed to MIL illuminates A MIL does not illuminate B A --> See step 20 B: Go to next step
5. CHECK MIL (CANISTER PUMP MODULE) Disconnect the canister pump module connector. Turn the engine switch on (IG). Check the MIL. RESULT Result Proceed to MIL illuminates A MIL does not illuminate B A --> See step 21 B: Go to next step
6. CHECK MIL (AIR SWITCHING VALVE ASSEMBLY FOR BANK 1) Disconnect the air switching valve connector. Turn the engine switch on (IG). Check the MIL. RESULT Result Proceed to MIL illuminates A MIL does not illuminate B A --> See step 23 B: Go to next step
7. CHECK MIL (AIR SWITCHING VALVE ASSEMBLY FOR BANK 2) Disconnect the air switching valve connector. Turn the engine switch on (IG). Check the MIL. RESULT Result Proceed to MIL illuminates A MIL does not illuminate B A --> See step 24 B: Go to next step
8. CHECK MIL (POWER STEERING OIL PRESSURE SWITCH) Disconnect the power steering oil pressure switch connector. Turn the engine switch on (IG). Check the MIL. RESULT Result Proceed to MIL illuminates A MIL does not illuminate B A --> See step 25 B: Go to next step
9. CHECK MIL (CAMSHAFT POSITION SENSOR) Disconnect the camshaft position sensor connector. Turn the engine switch on (IG). Check the MIL. RESULT Result Proceed to MIL illuminates A MIL does not illuminate B A --> See step 26 B: Go to next step
10. CHECK MIL (CRANKSHAFT POSITION SENSOR) Disconnect the crankshaft position sensor connector. Turn the engine switch on (IG). Check the MIL. RESULT Result Proceed to MIL illuminates A MIL does not illuminate B A --> See step 27 B: Go to next step
11. CHECK MIL (VVT SENSOR FOR INTAKE SIDE OF BANK 1) Disconnect the VVT sensor (for Intake Side of Bank 1) connector. Turn the engine switch on (IG). Check the MIL. RESULT Result Proceed to MIL illuminates A MIL does not illuminate B A --> See step 28 B: Go to next step
12. CHECK MIL (VVT SENSOR FOR EXHAUST SIDE OF BANK 1) Disconnect the VVT sensor (for Exhaust Side of Bank 1) connector. Turn the engine switch on (IG). Check the MIL. RESULT Result Proceed to MIL illuminates A MIL does not illuminate B A --> See step 29 B: Go to next step
13. CHECK MIL (VVT SENSOR FOR INTAKE SIDE OF BANK 2) Disconnect the VVT sensor (for Intake Side of Bank 2) connector. Turn the engine switch on (IG). Check the MIL. RESULT Result Proceed to MIL illuminates A MIL does not illuminate B A --> See step 30 B: Go to next step
14. CHECK MIL (VVT SENSOR FOR EXHAUST SIDE OF BANK 2) Disconnect the VVT sensor (for Exhaust Side of Bank 2) connector. Turn the engine switch on (IG). Check the MIL. RESULT Result Proceed to MIL illuminates A MIL does not illuminate B A --> See step 31 B: Go to next step
15. CHECK MIL (MANIFOLD ABSOLUTE PRESSURE SENSOR) Disconnect the manifold absolute pressure sensor connector. Turn the engine switch on (IG). Check the MIL. RESULT Result Proceed to MIL illuminates A MIL does not illuminate B A --> See step 32 B: Go to next step
16. CHECK HARNESS AND CONNECTOR Disconnect the throttle body connector. Disconnect the accelerator pedal position sensor connector. Disconnect the canister pump module connector. Disconnect the air switching valve connector (for Bank 1). Disconnect the air switching valve connector (for Bank 2). Disconnect the power steering oil pressure switch connector. Disconnect the camshaft position sensor connector. Disconnect the crankshaft position sensor connector. Disconnect the VVT sensor (for Intake Side of Bank 1) connector. Disconnect the VVT sensor (for Exhaust Side of Bank 1) connector. Disconnect the VVT sensor (for Intake Side of Bank 2) connector. Disconnect the VVT sensor (for Exhaust Side of Bank 2) connector. Disconnect the manifold absolute pressure sensor connector. Disconnect the ECM connectors. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition C30-13 (VCTA) - Body ground Always 10 kohms or higher G45-4 (VCPA) - Body ground Always 10 kohms or higher G45-2 (VCP2) - Body ground Always 10 kohms or higher C28-16 (VCV2) - Body ground Always 10 kohms or higher C28-15 (VCV1) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 22
17. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE»(ref-524126-S16095176252013012800000)
18. GO TO MIL CIRCUIT. Refer to «MIL Circuit»(ref-524264-S31118149522013012800000)
19. REPLACE THROTTLE BODY ASSEMBLY. Refer to «REMOVAL»(ref-524262-S00817459492013012800000)
20. REPLACE ACCELERATOR PEDAL POSITION SENSOR ASSEMBLY. Refer to «REMOVAL»(ref-524262-S17646998722013012800000)
21. REPLACE CANISTER. Refer to «REMOVAL»(/lexus/gx/j150-2009-2013/remont/auxiliary-emission-control-systems/#emission-control-system-service-information)
22. REPLACE ECM. Refer to «REMOVAL»(ref-524262-S01887464392013012800000)
23. REPLACE AIR SWITCHING VALVE ASSEMBLY. Refer to «REMOVAL»(/lexus/gx/j150-2009-2013/remont/auxiliary-emission-control-systems/#emission-control-system-service-information)
24. REPLACE AIR SWITCHING VALVE ASSEMBLY. Refer to «REMOVAL»(/lexus/gx/j150-2009-2013/remont/auxiliary-emission-control-systems/#emission-control-system-service-information)
25. REPLACE POWER STEERING OIL PRESSURE SWITCH. Refer to «REMOVAL»(ref-524262-S20406027822013012800000)
26. REPLACE CAMSHAFT POSITION SENSOR. Refer to «REMOVAL»(ref-524262-S27580867712013012800000)
27. REPLACE CRANKSHAFT POSITION SENSOR. Refer to «REMOVAL»(ref-524262-S07027689612013012800000)
28. REPLACE VVT SENSOR (FOR INTAKE SIDE OF BANK 1). Refer to «REMOVAL»(ref-524262-S27580867712013012800000)
29. REPLACE VVT SENSOR (FOR EXHAUST SIDE OF BANK 1). Refer to «REMOVAL»(ref-524262-S27580867712013012800000)
30. REPLACE VVT SENSOR (FOR INTAKE SIDE OF BANK 2). Refer to «REMOVAL»(ref-524262-S27580867712013012800000)
31. REPLACE VVT SENSOR (FOR EXHAUST SIDE OF BANK 2). Refer to «REMOVAL»(ref-524262-S27580867712013012800000)
32. REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR. Refer to «REMOVAL»(ref-524262-S01653891792013012800000)

The fuel pump circuit consists of the ECM, fuel pump and fuel pump ECU (which operates the fuel pump). Based on the engine output, the ECM determines the fuel pump speed. The speed is then converted to a duty signal and sent to the fuel pump ECU. Based on the signal sent from the ECM, the fuel pump ECU adjusts the fuel pump operation speed among 3 settings.

Scheme 62

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

Scheme 63

While the engine is being cranked, current flows from terminal STAR of the power management control ECU to the park/neutral position switch and also flows to terminal STA of the ECM (STA signal).

Scheme 64

This circuit opens and closes the Intake Air Control Valve (IACV) in response to the engine load in order to increase the intake efficiency (ACIS: Acoustic Control Induction System).

Scheme 65

Scheme 66

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 67

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 the detection of vehicle malfunctions by the ECM. When the engine switch is turned on (IG), 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 engine switch is first turned on (IG), the MIL should be illuminated and should then turn off when the engine is started. If the MIL remains illuminated or is not illuminated, conduct the following troubleshooting procedure using the Techstream.

Scheme 68

See also:
• ON-VEHICLE INSPECTION - Step 2
• ON-VEHICLE INSPECTION - Step 3
• ON-VEHICLE INSPECTION - Step 1
• REMOVAL
• ON-VEHICLE INSPECTION - Step 3
• ON-VEHICLE INSPECTION - Step 2
• ON-VEHICLE INSPECTION