DESCRIPTION
The ECM monitors its internal operation and it stores this DTC when it detects an internal malfunction.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P062F | An ECM internal error (EEPROM) (1 trip detection logic) | ECM |
MONITOR DESCRIPTION
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 Techstream.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0630 | When either of following conditions is met (1 trip detection logic): VIN is not stored in ECM Input VIN in ECM is not accurate | ECM |
The ECM monitors the output voltage to the throttle actuator. This self-check ensures that the ECM functioning properly. The output voltage is usually 0 V when the engine switch is turned Off. If the output voltage is higher than 7 V when the engine switch is turned off, the ECM will illuminate the MIL and set a DTC when the engine switch is turned on (IG).
| DTC | DTC Setting Condition | Trouble Area |
|---|---|---|
| P0657 | Throttle actuator power supply error (1 trip detection logic) | ECM |
The high pressure side fuel pump is attached to the insulator, which is attached to the cylinder head cover. The pump activates according to the position of the cam on the exhaust side camshaft (right bank).
The high pressure side fuel pump increases the pressure of the fuel supplied from the fuel pump in the fuel tank to 4 to 13 MPa (40.8 to 132.6 kgf/cm, 580 to 1886 psi) according to the operating condition, and it feeds the fuel to the fuel delivery pipe.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P1235 | Open or short in high pressure side fuel pump circuit for 1 second or more (1 trip detection logic) | Open or short in fuel pump for high pressure Fuel pump for high pressure Injector driver (EDU) ECM |
The injector driver has the integrated circuit (IC) which monitors the electrical circuit between the spill control valve and injector driver. If an open circuit is detected, the IC sends the malfunction signal (FPD) to the ECM. Then, the ECM illuminates the MIL and sets a 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 standard, the ECM will illuminate the MIL and set a DTC immediately.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P1607 | ECM CPUs malfunction (1 trip detection logic) | ECM |
The Swirl Control Valves (SCV) are built into the intake air surge tank assembly. The swirl control valves use a position sensor and a DC motor. A swirl control valve is located at one side of each pair of independent intake ports. Depending on signals from the ECM, the DC motor opens and closes the swirl control valves. The position sensor detects the opening angle of the swirl control valves. When the swirl control valves close, the velocity of the intake air flow that passes through the port on the other side of the independent intake port will become faster, enhancing lateral turbulent flow in the combustion chamber. As a result, when engine coolant temperature is low, atomization of fuel will be enhanced, stabilizing combustion in the cylinder. Also fuel consumption is decreased due to increased combustion efficiency when the engine is running at a low speed with a light load.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P2004 | The swirl control valve opening angle is 20°CA or more after requesting the swirl control valve full close (2 trip detection logic) | Intake air control valve actuator for swirl control valve circuit Intake air surge tank assembly (intake air control valve actuator for swirl control valve) Swirl control valve position sensor Swirl control valve ECM |
| P2006 | The swirl control valve opening angle is less than 35°CA after requesting the swirl control valve full open (2 trip detection logic) |
HINT
After confirming DTC P2004 or P2006, use Techstream to confirm the IAC Sensor Voltage (SCV position sensor output voltage) while performing Control the SCV Duty Ratio of the Active Test.
| Control the SCV Duty Ratio operation | IAC Sensor Voltage |
|---|---|
| 100% | 3.2 to 4.8 V |
| 100% | 0.2 to 1.0 V |
REFERENCE (NORMAL CONDITION)
When the ECM has requested a swirl control valve close operation but the swirl control valve's actual opening angle is 20°CA or more for 10 seconds, DTC P2004 is output. When the ECM has requested a swirl control valve open operation but the swirl control valve's actual opening angle is less than 35°CA for 10 seconds, DTC P2006 is output.
The ECM activates the intake air control valve actuator for Swirl Control Valve (SCV), which opens and closes swirl control valve. The ECM activates the DC motor based on engine speed, coolant temperature, engine load signals and other conditions.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P2009 | Both of the following conditions continue for 0.5 seconds (1 trip detection logic): (a) The output duty of the intake air control valve actuator for swirl control valve is 100% or more. (b) The current of the intake air control valve actuator for swirl control valve is less than 0.35 A. | Open or short in intake air control valve actuator for swirl control valve circuit Intake air surge tank assembly (intake air control valve actuator for swirl control valve) ECM |
| P2010 | Either of the following conditions continues for 6 times or more (1 trip detection logic). (a) The motor drive IC is overcurrent. (b) The motor drive IC overheats. |
When the voltage of the DC motor (intake air control valve actuator) deviates from the standard range, the ECM determines that a malfunction has occurred and sets a DTC.
The Swirl Control Valve (SCV) position sensor is a non-contact type.
The position sensor measures the opening angle of the SCV. The sensor is reliable and accurate, as it is electrically controlled by Hall elements.
Scheme 36
| DTC No. | DTC Detection Connection | Trouble Area |
|---|---|---|
| P2014 | Swirl control valve position sensor output voltage flutters up and down beyond the normal operating range (Less than 0.2 V, or more than 4.8 V for more than 0.5 seconds) (Open or short) (1 trip detection logic) | Open or short in swirl control valve position sensor circuit Swirl control valve position sensor ECM |
| P2016 | Swirl control valve position sensor output voltage is less than 0.2 V for more than 0.5 seconds (Short) (1 trip detection logic) | Short in swirl control valve position sensor circuit Swirl control valve position sensor ECM |
| P2017 | Swirl control valve position sensor output voltage is more than 4.8 V for more than 0.5 seconds (Open) (1 trip detection logic) | Open in swirl control valve position sensor circuit Swirl control valve position sensor ECM |
HINT
After confirming DTC P2014, P2016 or P2017, use Techstream to confirm the IAC Sensor Voltage (Swirl control valve position sensor output voltage) by entering the following menus: Powertrain / Engine / Data List / All Data / IAC Sensor Voltage.
| IAC Sensor Voltage | Malfunction |
|---|---|
| 0.2 V or less | IAC1 circuit short VC circuit open |
| 4.8 V or more | VC and IAC1 circuit short-circuited IAC1 circuit open E2 circuit open |
The ECM's IAC1 terminal voltage increases in correlation with the opening angle of the swirl control valve. When the swirl control valve is fully closed, approximately 0.6 V is applied to the IAC1 terminal. When the swirl control valve is fully open, approximately 3.6 V is applied to the IAC1 terminal.
When the output voltage of the IAC1 terminal deviates from the standard range, the ECM determines that a malfunction has occurred in the position sensor 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 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 does not use a throttle cable.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P2102 | Both of the following conditions continue for 2 seconds (1 trip detection logic): (a) Throttle actuator drive duty cycle is 80% or more (b) Throttle actuator current is less than 0.5 A | Open in throttle actuator circuit Throttle actuator ECM |
| P2103 | Either condition is met (1 trip detection logic): Hybrid IC diagnosis signal failure Hybrid IC high current limiter port failure | Short in throttle actuator circuit Throttle actuator Throttle valve Throttle body assembly ECM |
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.
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, 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 Electronic Throttle Control System (ETCS) does not use a throttle cable.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P2111 | The ECM signals the throttle actuator to close, but the actuator is stuck (1 trip detection logic). | Throttle actuator Throttle body assembly Throttle valve Wire harness or connector ECM |
| P2112 | The ECM signals the throttle actuator to close, but the actuator is stuck (1 trip detection logic). | Throttle actuator Throttle body assembly Throttle valve Wire harness or connector ECM |
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 (ETCS) 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 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 engine switch off. The ECM then allows the current to flow to the throttle actuator so that it can be restarted.
HINT
This electronic throttle control system does not use a throttle cable.
Scheme 37
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P2118 | An open in electronic throttle control system power source (+BM) circuit (1 trip detection logic) | Open in ETCS power source circuit Battery Battery terminals ETCS fuse ECM |
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.
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.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P2119 | Throttle valve opening angle continues to vary greatly from the target opening angle (1 trip detection logic). | Electronic Throttle Control System (ETCS) Wire harness or connector 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 the DTC.
HINT
- These DTCs are related to the accelerator pedal sensor assembly.
- This ETCS (Electronic Throttle Control System) does not use a throttle cable.
The Accelerator Pedal Position (APP) 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 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 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 38
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P2120 | VPA fluctuates rapidly beyond upper and lower malfunction thresholds for 0.5 seconds or more (1 trip detection logic) | Accelerator Pedal Position (APP) sensor ECM |
| P2122 | VPA 0.4 V or less for 0.5 seconds or more when accelerator pedal depressed (1 trip detection logic) | APP sensor Open in VCP1 circuit Open or ground short in VPA circuit ECM |
| P2123 | VPA 4.8 V or more for 2.0 seconds or more (1 trip detection logic) | APP sensor Open in EPA circuit ECM |
| P2125 | VPA2 fluctuates rapidly beyond upper and lower malfunction thresholds for 0.5 seconds or more (1 trip detection logic) | APP sensor ECM |
| P2127 | VPA2 is 1.2 V or less for 0.5 seconds or more when accelerator pedal depressed (1 trip detection logic) | APP sensor Open in VCP2 circuit Open or ground short in VPA2 circuit ECM |
| P2128 | Conditions (a) and (b) continue for 2.0 seconds or more (1 trip detection logic): (a) VPA2 is 4.8 V or more (b) VPA is between 0.4 V and 3.45 V | APP sensor Open in EPA2 circuit ECM |
| P2138 | Condition (a) or (b) continues for 2.0 seconds or more (1 trip detection logic): (a) Difference between VPA and VPA2 is 0.02 V or less (b) VPA 0.4 V or less and VPA2 is 1.2 V or less | Short between VPA and VPA2 circuits APP sensor ECM |
HINT
When any of these DTCs are set, check the APP sensor voltage by entering the following menus on Techstream: Powertrain / Engine / Data List / All Data / Accel Sensor Out No. 1 and Accel Sensor Out No. 2.
| Trouble Area | Accelerator Pedal Fully Released | Accelerator Pedal Fully Depressed | ||
|---|---|---|---|---|
| Accel Sensor Out No. 1 | Accel Sensor Out No. 2 | Accel Sensor Out No. 1 | Accel Sensor Out No. 2 | |
| Open in VCP circuit | 0 to 0.2 V | 0 to 0.2 V | 0 to 0.2 V | 0 to 0.2 V |
| Open or ground short in VPA circuit | 0 to 0.2 V | 1.2 to 2.0 V | 0 to 0.2 V | 3.4 to 4.75 V |
| Open or ground short in VPA2 circuit | 0.5 to 1.1 V | 0 to 0.2 V | 2.6 to 4.5 V | 0 to 0.2 V |
| Open in EPA circuit | 4.5 to 4.98 V | 4.5 to 4.98 V | 4.5 to 4.98 V | 4.5 to 4.98 V |
| Normal condition | 0.5 to 1.1 V | 1.2 to 2.0 V | 2.6 to 4.5 V | 3.4 to 4.75 V |
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 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 is less than 0.4 V for more than 0.5 seconds when the accelerator pedal is fully depressed, DTC P2122 is stored.
HINT
This DTC relates to the accelerator pedal position sensor.
Refer to DTC P2120. Refer to DESCRIPTION.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P2121 | Either of following conditions 1 or 2 met for 0.5 seconds (1 trip detection logic) 1. Difference between VPA and VPA2 is less than 0.4 V, or higher than 1.2 V. (learned value of accelerator off position) 2. Difference between VPA and VPA2 is greater than or equal to the specified value. | Accelerator Pedal Position (APP) sensor ECM |
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 set 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 level, 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 the planar type and is integrated with the 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 into 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 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 39
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P2195 P2197 | Conditions (a) and (b) continue for 5 seconds or more (2 trip detection logic): (a) Air fuel ratio sensor voltage more than 3.8 V (b) Heated oxygen sensor voltage is 0.21 V or more | Open or short in air fuel ratio sensor (bank 1, 2 sensor 1) circuit Air fuel ratio sensor (bank 1, 2 sensor 1) Fuel pressure (low pressure side) Fuel pressure (high pressure side) Air induction system Fuel injector assembly Fuel pressure sensor ECM |
| While fuel-cut operation performed (during vehicle deceleration), air fuel ratio sensor current is 2.2 mA or more for 3 seconds (2 trip detection logic) | Air fuel ratio sensor (bank 1, 2 sensor 1) ECM | |
| P2196 P2198 | Conditions (a) and (b) continue for 5 seconds or more (2 trip detection logic): (a) Air fuel ratio sensor voltage less than 2.8 V (b) Heated oxygen sensor voltage is less than 0.59 V | Open or short in air fuel ratio sensor (bank 1, 2 sensor 1) circuit Air fuel ratio sensor (bank 1, 2 sensor 1) Fuel pressure (low pressure side) Fuel pressure (high pressure side) Air induction system Fuel injector assembly Fuel pressure sensor ECM |
| While fuel-cut operation performed (during vehicle deceleration), air fuel ratio sensor current is less than 0.47 mA for 3 seconds (2 trip detection logic) | Air fuel ratio sensor (bank 1, 2 sensor 1) ECM |
HINT
- DTCs P2195 and P2196 indicate malfunctions related to the bank 1 air fuel ratio sensor circuit.
- DTCs P2197 and P2198 indicate malfunctions related to the bank 2 air fuel ratio sensor circuit.
- When any of these DTCs are set, check the air fuel ratio sensor output voltage by entering the following menus: Powertrain / Engine / Data List / All Data / AFS Voltage B1S1 or AFS Voltage B2S1.
- Short-term fuel trim values can also be read using the Techstream.
- The ECM regulates the voltages at the A1A+, A2A+, A1A- and A2A- terminals of the ECM to a constant level. Therefore, the air fuel ratio sensor output voltage cannot be confirmed without using the Techstream.
- If an air fuel ratio sensor malfunction is detected, the ECM sets a DTC.
Sensor Voltage Detection Monitor
Under air fuel ratio feedback control, If the air fuel ratio sensor output voltage is less than 2.8 V (very rich condition) for 5 seconds despite the heated oxygen sensor output voltage being less than 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 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 2.2 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 stores DTC P2195 or P2197 (stuck on high side). If the air fuel ratio sensor output is less than 0.47 mA for more than 3 seconds of cumulative time, the ECM stores DTC P2196 or P2198 (stuck on low side).
Scheme 40
These DTCs are set when there is an open or short in the A/F sensor circuit, or if A/F sensor output drops. To detect these problems, the voltage of the A/F sensor is monitored when turn 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 A/F 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 A/F sensor. If the same malfunction is detected in next driving cycle, the MIL will be illuminated and a DTC will be stored.
The A/F 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 0.6V and 4.5V 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 41
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P2237 P2240 | Open in the circuit between terminals A1A+ (A2A+) and A1A- (A2A-) of the air fuel ratio sensor while engine running (2 trip detection logic) | Open or short in A/F sensor (bank 1, 2 sensor 1) circuit A/F sensor (bank 1, 2 sensor 1) ECM |
| P2238 P2241 | Case 1: Condition (a) or (b) continues for 5.0 seconds or more(2 trip detection logic):(a) Voltage at terminal A1A+ (A2A+) is 0.5 V or less(b) Voltage difference between terminals A1A+ (A2A+) and A1A- (A2A-) is 0.1 V or less Case 2: Air fuel ratio sensor admittance: Less than 0.0074 1/ohms(2 trip detection logic) | Open or short in A/F sensor (bank 1, 2 sensor 1) circuit A/F sensor (bank 1, 2 sensor 1) ECM |
| P2239 P2242 | A1A+ (A2A+) voltage is more than 4.5 V (2 trip detection logic) | Open or short in A/F sensor (bank 1, 2 sensor 1) circuit A/F sensor (bank 1, 2 sensor 1) ECM |
| P2252 P2255 | A1A- (A2A-) voltage is 0.5 V or less (2 trip detection logic) | Open or short in A/F sensor (bank 1, 2 sensor 1) circuit A/F sensor (bank 1, 2 sensor 1) ECM |
| P2253 P2256 | A1A- (A2A-) voltage is more than 4.5 V (2 trip detection logic) | Open or short in A/F sensor (bank 1, 2 sensor 1) circuit A/F sensor (bank 1, 2 sensor 1) ECM |
These DTCs are output when there is an open or short in the A/F sensor circuit, or if A/F sensor output drops. To detect these problems, the voltage of the A/F sensor is monitored when turn 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 A/F sensor is between 0.5 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 A/F 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 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 (Evaporative Emission) system. The ECM monitors for leaks and actuator malfunctions based on the EVAP pressure.
HINT
*: If the engine coolant temperature is not less than 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 less than 35°C (95°F) 7 hours after the engine switch is turned off, the monitor check starts 2.5 hours later.
| Sequence | Operation | Description | Duration |
|---|---|---|---|
| ECM activation | Activated by soak timer, 5 hours (7 or 9.5 hours) after engine switch is turned off. | ||
| A | Atmospheric pressure measurement | Vent valve is turned off (vent) and EVAP system pressure is measured by ECM in order to register atmospheric pressure. If pressure in EVAP system is not between 70 kPa(abs) and 110 kPa(abs) [525 mmHg(abs) and 825 mmHg(abs)], ECM cancels EVAP system monitor. | 60 seconds |
| B | First reference pressure measurement | In order to determine reference pressure, leak detection pump creates negative pressure (vacuum) through reference orifice and then ECM checks if leak detection pump and vent valve operate normally. | 60 seconds |
| C | EVAP system pressure measurement | Vent valve is turned on (closed) to shut EVAP system. Negative pressure (vacuum) is created in EVAP system, and then EVAP system pressure is measured. Write down measured value as they will be used in leak check. If EVAP pressure does not stabilize within 15 minutes, ECM cancels EVAP system monitor. | 15 minutes* |
| D | Purge VSV monitor | Purge VSV is opened and then EVAP system pressure is measured by ECM. Large increase indicates normal. | 10 seconds |
| E | Second reference pressure measurement | After second reference pressure measurement, leak check is performed by comparing first and second reference pressure measurements. If stabilized system pressure is higher than second reference pressure, ECM determines that there is a leak in EVAP system. | 60 seconds |
| Final check | Atmospheric pressure is measured and then monitoring result is recorded by ECM. |
*: If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.
Scheme 42
P2420: Vent valve stuck open (vent)
In operation C, the vent valve turns on (closed) 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 43
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 witch can only be performed after the engine is stopped. The soak timer is built into the ECM.
Scheme 44
- 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.
- 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).
The engine control unit and the Transmission Control Module (TCM) are located inside the ECM. The engine control unit intercommunicates with the TCM through the Controller Area Network (CAN).
If there is a problem in this intercommunication, the ECM sets a DTC.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| U0101 | Following conditions are met for 2 seconds (1 trip detection logic): Engine switch on (IG) Battery voltage is 10.5 V or more No intercommunication between ECM and TCM | ECM |
When the engine switch is turned on (IG), the battery voltage is applied to terminal IGSW of the ECM. The ECM MREL output signal causes a current to flow to the coil, closing the contacts of the EFI MAIN relay and supplying power to terminal +B and +B1 of the ECM.
Scheme 45
The ECM constantly produces 5 V from the battery voltage supplied to the +B (BATT) terminal to operate its microprocessor. The ECM also provides this power to the sensors through the VC output circuit.
Scheme 46
When the VC circuit is shorted, the microprocessor in the ECM and sensors that are supplied 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 when the engine switch is turned on (IG). The MIL goes off when the engine is started.
Scheme 47
Scheme 48
Refer to DTC P0230. Refer to DTC P0230: Fuel Pump Primary Circuit.
The cranking holding control system provides current to the starter when the ECM detects the engine switch's start signal (STSW). When the ECM performs a firing judgment, the system cuts current to the starter. When an ECM receives the STSW signal, it turns on the ST CUT relay, which prevents flickering of the combination meter, clock, audio system, etc. Also, the ECM sends a signal to the ECM's STAR terminal. Then the STAR output signal travels through the park/neutral position (PNP) switch to the STARTER relay, causing the starter to activate.
When the engine is cranking, the starter operation signal is sent to the ECM's STA terminal.
Scheme 49
The cold start injector is attached to the intake air surge tank and is designed to improve startability when the engine is cold. It operates when the engine coolant temperature is -12°C or less, and the starter signal is ON.
Scheme 50
When the Intake Air Control Valve (IACV) opens and closes, the Acoustic Control Induction System (ACIS) control circuit causes the engine load intake efficiency to increase. When the engine is running at 2450 to 4100 rpm and the throttle valve opening angle is 30° or more, current flows through the ACIS control circuit and the IACV closes. For all other situations, current does not flow through the ECM and the IACV is open.
Scheme 51
Scheme 52
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 53
Activation Conditions
- Vehicle is running at or above the specified speed.
- 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
- 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 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
- 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 malfunction detections by the ECM.
By turning the engine switch 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 turned on (IG), the MIL should be illuminated and should then turn off after engine is started. If the MIL remains illuminated or is not illuminated, conduct the following troubleshooting procedure using Techstream.
