DTC DETECTION LOGIC AND CONDITIONS [L8, LF, L3]

id0102a1100300

CMP Timing

CMP timing over-advanced (P0011)

•  The actual valve timing is over-advanced by 17 ° from the target valve timing for specified period when the oil control valve (OCV) is controlled in the maximum valve timing retard condition.

―  Engine speed is below 4,000 rpm

―  Engine coolant temperature is 70—110 °C {158—230 °F}

CMP timing over-retarded (P0012)

•  Actual valve timing is over-retarded by 19 ° from the target valve timing for specified period when the oil control valve (OCV) system control is within the feedback range.

―  Engine speed is below 4,000 rpm

―  Engine coolant temperature is 70—110 °C {158—230 °F}

A/F Sensor Heater, HO2S Heater

A/F sensor heater control circuit problem (P0030)

•  OBD system monitors the output signal voltage from A/F sensor which is proportion to the element impedance of A/F sensor.

•  If the output signal voltage isn’t between 0.75 V and 1.5 V after specified time from engine start, heater performance considered failed.

―  Battery voltage: 10—18 V

―  Time from engine start is 74 s or more

A/F sensor heater circuit low input (P0031)

•  The PCM monitors the A/F sensor heater output voltage. if the PCM turns the A/F sensor heater off or on but the A/F sensor heater circuit remains low voltage, the PCM determines that the A/F sensor heater circuit has a malfunction.

A/F sensor heater circuit high input (P0032)

•  The PCM monitors the A/F sensor heater output voltage. if the PCM turns the A/F sensor heater off or on but the A/F sensor heater circuit remains high voltage, the PCM determines that the A/F sensor heater circuit has a malfunction.

HO2S heater circuit low input (P0037)

•  The PCM monitors the HO2S heater output voltage. if the PCM turns the HO2S heater off or on but the HO2S heater circuit remains low voltage, the PCM determines that the HO2S heater circuit has a malfunction.

HO2S heater circuit high input (P0038)

•  The PCM monitors the HO2S heater output voltage. if the PCM turns the HO2S heater off or on but the HO2S heater circuit remains high voltage, the PCM determines that the HO2S heater circuit has a malfunction.

MAF Sensor

MAF circuit range/performance problem (P0101)

•  PCM monitors mass intake air flow amount when the engine is running.

―  If the mass intake air flow amount is above 44 l/s (L8, LF), 50 l/s (L3) for 5 s and the engine speed is below 2,000 rpm with the engine running, the PCM determines that the detected mass intake air flow amount is too high.

―  If the mass intake air flow amount is below 6—43 l/s (L8, LF), 6—57.8 l/s (L3) (The value depends on engine speed.) for 5 s and the engine speed is above 1,000 rpm with the engine running and the throttle opening angle above 50 %, the PCM determines that detected the mass intake air flow amount is too low.

MAF sensor circuit low input (P0102)

•  The PCM monitors input voltage from the MAF sensor when the engine running. If the input voltage is below 0.21 V, the PCM determines that the MAF circuit has a malfunction.

MAF sensor circuit high input (P0103)

•  The PCM monitors the input voltage from the MAF sensor when the engine running. If the input voltage is above 4.9 V, the PCM determines that the MAF circuit has a malfunction.

MAP Sensor

MAP sensor circuit low input (P0107)

•  The PCM monitors the input voltage from the MAP sensor when intake air temperature is above –10 °C {14 °F}. If the input voltage is below 0.1 V, the PCM determines that the MAP sensor circuit has a malfunction.

MAP sensor circuit high input (P0108)

•  The PCM monitors the input voltage from the MAP sensor when intake air temperature is above –10 °C {14 °F}. If input the voltage is above 4.9 V, the PCM determines that the MAP sensor circuit has a malfunction.

―  Calculated load: 13—32 %

Intake Air Temperature (IAT) Sensor

IAT circuit range/performance problem (P0111)

•  If the intake air temperature is higher than the engine coolant temperature by 40 °C {72 °F} for 60 s with key on, the PCM determines that there is a IAT sensor performance problem.

IAT sensor circuit low input (P0112)

•  The PCM monitors the IAT sensor signal. If the PCM detects that the IAT sensor voltage is below 0.16 V, the PCM determines that the IAT sensor circuit has a malfunction.

IAT sensor circuit high input (P0113)

•  The PCM monitors the IAT sensor signal. If the PCM detects that the IAT sensor voltage is above 4.8 V, the PCM determines that IAT sensor circuit has a malfunction.

Engine Coolant Temperature (ECT) Sensor

ECT sensor circuit low input (P0117)

•  The PCM monitors the ECT sensor signal. If the PCM detects that the ECT sensor voltage is below 0.2 V, the PCM determines that the ECT sensor circuit has a malfunction.

ECT sensor circuit high input (P0118)

•  The PCM monitors the ECT sensor signal. If the PCM detects that the ECT sensor voltage is above 4.6 V, the PCM determines that the ECT sensor circuit has a malfunction.

Excessive time to enter closed loop fuel control (P0125)

•  The PCM monitors the ECT sensor signal after engine is started while the engine is cold. If the engine coolant temperature does not reach the expected temperature for a specified period, the PCM determines that it has taken an excessive amount of time for the engine coolant temperature to reach the temperature necessary to start closed-loop fuel control.

Throttle Position (TP) Sensor

TP sensor No.1 circuit low input (P0122)

•  If the PCM detects that the TP sensor voltage is below 0.2 V while the engine is running, the PCM determines that the TP circuit has a malfunction.

TP sensor No.1 circuit high input (P0123)

•  If the PCM detects the TP sensor No.1 voltage is to be above 4.85 V after ignition switch to the ON position, PCM determines that TP circuit has a malfunction.

TP sensor No.2 circuit low input (P0222)

•  If PCM detects TP sensor No.2 voltage is to be below 0.2 V after the ignition switch to the ON position, the PCM determines that TP circuit has a malfunction.

TP sensor No.2 circuit high input (P0223)

•  If the PCM detects the TP sensor No.2 voltage is to be above 4.85 V after the ignition switch to the ON position, the PCM determines that the TP circuit has a malfunction.

TP sensor No.1/No.2 voltage correlation problem (P2135)

•  The PCM compares the input voltage from TP sensor No.1 with the input voltage from TP sensor No.2 when the engine is running. If the difference is more than the specification, the PCM determines that there is a TP sensor No.1/No.2 voltage correlation problem.

A/F sensor

A/F sensor circuit low input (P0131)

•  The PCM monitors the input voltage from the A/F sensor while the engine is running. If the input voltage is above 1.0 V for 2 s, the PCM determines that the A/F sensor circuit voltage is low.

A/F sensor circuit high input (P0132)

•  The PCM monitors the input voltage from the A/F sensor when the engine is running. If the input voltage is less than 1.0 V for 2 s, the PCM determines that the A/F sensor circuit voltage is high.

A/F sensor circuit problem (P0133)

•  A/F sensor malfunction is detected by measuring of the average frequency of A/F sensor signal, time required to pass from rich to lean, time required to pass from lean to rich.

•  The average frequency of A/F sensor signal is more than the threshold value.

―  A/F sensor heater, HO2S heater, A/F sensor, HO2S, and TWC Repair Verification Drive Mode

―  Following conditions are met:

•  A/F sensor heater monitor is completed.

•  Fuel system loop status is closed loop fuel control.

―  ECT sensor and A/F sensor heater and normal.

―  Engine speed: 1410—3500 rpm

―  Charging efficiency: 15—59 % (MTX), 20—59 % (ATX)

―  Engine coolant temperature above 70 °C {158 °F}

A/F sensor no activity detected (P0134)

•  The PCM monitors the input voltage from A/F sensor when the following conditions are met. Under the following monitoring conditions, the input voltage more than 3.22 V, the PCM determines that the A/F sensor is not activated.

―  A/F sensor heater, HO2S heater, A/F sensor, HO2S and TWC Repair Verification Drive Mode

―  Following conditions are met

•  A/F sensor heater is turned on for more than 30 s.

•  Battery voltage: 10 —18 V

A/F sensor signal stuck lean (P2195)

•  The PCM monitors the A/F sensor output current when the following conditions are met. If the average output current is more than 1.2 A for 25 s, the PCM determines that the A/F sensor signal remains lean.

MONITORING CONDITION

―  ECT: more than 70 °C {158 °F}

―  Engine speed: 1,000—3,200 rpm

―  Charging efficiency: 20—62.5%

―  Output voltage from the HO2S: more than 0.2 V

A/F sensor signal stuck rich (P2196)

•  The PCM monitors the A/F sensor output current when the following conditions are met. If the average output current is less than 0.85 A for 25 s, the PCM determines that the A/F sensor signal remains rich.

MONITORING CONDITION

―  ECT: more than 70 °C {158 °F}

―  Engine speed: 1,000—3,200 rpm

―  Charging efficiency: 20—62.5%

―  Output voltage from the HO2S: less than 0.8 V

A/F sensor positive current control circuit open (P2237)

•  The PCM monitors A/F sensor positive current control circuit voltage. If the voltage is not changed against the PCM control value while the engine running, the PCM determines that the A/F sensor positive current control circuit is open.

A/F sensor negative current control circuit open (P2251)

•  The PCM monitors A/F sensor negative current control circuit voltage. If the voltage is not changed against the PCM control value while the engine running, the PCM determines that the A/F sensor negative current control circuit is open.

HO2S

HO2S circuit high input (P0138)

•  The PCM monitors input voltage from HO2S. If the input voltage from the HO2S is above 1.2 V for 0.8 s, the PCM determines that circuit input is high.

HO2S no activity detected (P0140)

•  The PCM monitors the input voltage from the HO2S when the following conditions are met. Under the following monitoring conditions, if the input voltage from the HO2S does not even exceed 0.55 V though the short term fuel trim is controlled up to 20.5 % for 9.6 s, the PCM determines that sensor circuit is not activated.

―  A/F sensor heater, HO2S heater, A/F sensor, HO2S and TWC repair verification drive mode

―  Following conditions are met for above 20.8 s

•  Engine speed is above 1,500 rpm.

•  Engine coolant temperature is above 70 °C {158 °F}.

Misfire Monitor

Random misfire detected (P0300), Cylinder misfire detection (P0301, P0302, P0303, P0304)

•  The PCM monitors CKP sensor input signal interval time. The PCM calculates the change of interval time for each cylinder. If the change of interval time exceeds the preprogrammed criteria, the PCM detects a misfire in the corresponding cylinder. While the engine is running, the PCM counts the number of misfires that occurred at 200 crankshaft revolutions and 1,000 crankshaft revolutions and calculates the misfire ratio for each crankshaft revolution. If the ratio exceeds the preprogrammed criteria, the PCM determines that a misfire, which can damage the catalytic converter or affect emission performance, has occurred.

Knock Sensor

KS circuit low input (P0327)

•  The PCM monitors input signal from the KS when the engine is running. If the input voltage is below 0.06 V the PCM determines that the KS circuit has a malfunction.

KS circuit high input (P0328)

•  The PCM monitors the input signal from the KS when the engine is running. If the input voltage is above 4.9 Vthe PCM determines that KS circuit has a malfunction.

Crankshaft Position (CKP) Sensor

CKP sensor circuit malfunction (P0335)

•  If the PCM does not receive the input voltage from the CKP sensor for 4.2 s while the MAF is 1.95 g/s {0.25 lb/min.} or above, the PCM determines that the CKP sensor circuit has a malfunction.

Camshaft Position (CMP) Sensor

Camshaft position (CMP) sensor circuit malfunction (P0340)

•  The PCM monitors the input voltage from the CMP sensor when the engine is running. If the PCM does not receive the input voltage from the CMP sensor while the PCM receives the input signal from the CKP sensor, the PCM determines that the CMP circuit has a malfunction.

EGR Valve

EGR valve (stepper motor) circuit problem (P0403)

•  The PCM monitors the input voltage from EGR valve. If the voltage remain low or high, the PCM determines that the EGR valve circuit has a malfunction.

Catalyst System

Warm up catalyst system efficiency below threshold (P0420)

•  PCM compares number of A/F sensor and HO2S inversions for a predetermined time. PCM monitors number of inversions rear sides performs while front side inverts for specified number of times when the following monitoring conditions are met. detects inversion ratio is below threshold, PCM determines that catalyst system has deteriorated.

―  Calculated TWC temperature: more than 400 °C {752 °F}

―  Engine speed: 1,500—3,000 rpm

―  LOAD: 17—50 % (MTX), 20—50 % (ATX) (at engine speed 2,000 rpm)

Purge Solenoid Valve

Purge solenoid valve circuit problem (P0443)

•  The PCM monitors the input voltages from the purge solenoid valve. If the voltage remains low or high, the PCM determines that the purge solenoid valve circuit has a malfunction.

Fan Control System

Fan relay No.1 control circuit malfunction (P0480)

•  PCM monitors cooling fan relay No.1 control signal. If voltage remains low or high, PCM determines that fan relay No.1 circuit has a malfunction.

Fan relay No.2 and No.3 control circuit malfunction (P0481)

•  PCM monitors cooling fan relay No.2 and No.3 control signal. If voltage remains low or high, PCM determines that fan relay No.2 and No.3 circuit has a malfunction.

Fan relay No.4 control circuit malfunction (P0482)

•  PCM monitors cooling fan relay No.4 control signal. If voltage remains low or high, PCM determines that fan relay circuit has a malfunction.

Vehicle Speed Sensor (VSS)

VSS circuit problem (P0500)

With ABS/DSC

•  If an error in the wheel speed signal from the ABS/DSC HU/CM is detected by CAN, the PCM detects a malfunction in the vehicle speed signal.

Without ABS/DSC

•  Vehicle speed signal from vehicle speed sensor is below 3.7 km/h {2.3 mph} when the following conditions are met:

―  Neutral switch and clutch pedal position switch are OFF

―  Load is above 40 %

―  Engine speed is 2,000 rpm or above

―  Brake switch is OFF

Idle Air Control (IAC) Valve

IAC system problem (P0505)

•  The PCM cannot control idle speed toward target idle speed while KOER self test.

Idle control system RPM lower than expected (P0506)

•  Actual idle speed is lower than expected by 100 rpm for 14 s, when brake pedal is depressed (brake switch is on) and steering wheel is held straight ahead (power steering pressure (PSP) switch is off).

Note

•  If intake air temperature is below –10 °C {14 °F}, the PCM cancels diagnosis of P0506.

Idle control system RPM higher than expected (P0507)

•  Actual idle speed is higher than expected by 200 rpm for 14 s, when the brake pedal is depressed (brake switch is on) and steering wheel is held straight ahead (power steering pressure (PSP) switch is off).

Note

•  If intake air temperature is below –10 °C {14 °F}, the PCM cancels diagnosis of P0507.

Power Steering Pressure (PSP) Switch

PSP switch circuit malfunction (P0550)

•  The PCM monitors PSP switch signal. If input voltage is low voltage (switch stays on) for 1 min. when the VSS is above 60 km/h {37 mph} and ECT is above 60 °C {140 °F}, the PCM determines that PSP switch circuit has a malfunction.

Cruise Control Switch

Cruise control switch circuit malfunction (P0564)

•  The PCM monitors the cruise control switch signal. If the PCM detects that any one of following switches (Main, CANCEL, SET/COAST, RESUME/ACCEL) remains on for 2 min, the PCM determines that the cruise control switch circuit has a malfunction.

PCM Configuration

PCM memory check sum error (P0601)

•  PCM internal memory check sum error

PCM programming error (P0602)

•  No configuration data in the PCM

Note

•  If the “PCM CONFIGURATION” is successful, the PCM stores DTC P0602 and illuminates the MIL (system is normal). Clear DTC P0602 using the WDS or equivalent after the “PCM CONFIGURATION”.

•  The MIL goes out after three drive cycles with no failure (DTCs remain in PCM).

PCM RAM error (P0604)

•  PCM internal RAM malfunction.

ECM/PCM processor (P0606)

•  The PCM internal CPU malfunction

PCM performance problem (P0607)

•  PCM internal malfunction.

PCM vehicle options error (P0610)

•  PCM data configuration error

PCM B+ voltage low (P2507)

•  The PCM monitors the voltage of back-up battery positive terminal. If the PCM detects battery positive terminal voltage below 2.5 V for 2 s, the PCM determines that the backup voltage circuit has a malfunction.

Throttle Actuator

Throttle actuator control circuit range/performance problem (P0638)

•  The PCM compares the actual TP with the target TP when the engine is running. If the difference is more than the specification, the PCM determines that there is a throttle actuator control circuit range/performance problem.

Throttle actuator circuit open (P2100)

•  The PCM monitors the electronic throttle valve motor current. If the PCM detects that the electronic throttle valve motor current is below the threshold current, the PCM determines that the electronic throttle valve motor circuit has a malfunction.

Throttle actuator circuit range/performance (P2101)

•  If any of the following conditions continue for a specified period of time or more the PCM detects a malfunction in the throttle actuator.

―  The voltage of the motor power supply is 4 V or less while the motor relay is on

―  There is a system error in the electrical throttle control system of the PCM

―  The temperature of the electrical throttle control system in the PCM is 180 °C {356 °F} or more

Throttle actuator circuit low input (P2102)

•  PCM monitors the throttle actuator circuit current. If the PCM detects that the throttle actuator circuit current is excessively low, the PCM determines that the throttle actuator circuit was a malfunction.

Throttle actuator circuit high input (P2103)

•  PCM monitors the throttle actuator circuit current. If the PCM detects that the throttle actuator circuit current is excessively high, the PCM determines that the electronic throttle actuator circuit has a malfunction.

Throttle actuator control module processor error (P2107)

•  Throttle actuator control module internal processor error

Throttle actuator control module performance error (P2108)

•  If the PCM detects either of the following conditions, the PCM determines that throttle actuator control system has a malfunction.

―  TP sensor power supply voltage below 4.4 V

―  TP sensor No.1 output voltage below 0.20 V or above 4.85 V (DTC P0122 or P0123)

―  TP sensor No.2 output voltage below 0.20 V or above 4.85 V (DTC P0222 or P0223)

―  PCM internal circuit for TP sensor No.1 input circuit malfunction.

Throttle actuator control throttle body range/performance problem (P2119)

•  The PCM compares the TP with the default TP when the ignition switch is off. If the TP is higher than the default TP, the PCM determines that there is a throttle actuator control throttle body range/performance problem.

Variable Intake-air System (VIS) Control Solenoid Valve

Variable intake-air solenoid valve circuit low input (P0661)

•  The PCM monitors the variable intake-air solenoid valve control signal. If the PCM turns variable intake-air solenoid valve off but voltage still remains low, the PCM determines that variable intake-air solenoid valve circuit has a malfunction.

Variable intake-air solenoid valve circuit high input (P0662)

•  The PCM monitors the variable intake-air solenoid valve control signal. If the PCM turns variable intake-air solenoid valve on but voltage still remains high, the PCM determines that the variable intake-air solenoid valve circuit has a malfunction.

Brake Switch

Brake switch circuit problem (P0571)

•  The PCM monitors switching in conjunction with brake switches No.1 and No.2. If either No.1 or No.2 do not switch for a continuous five times even though either No.1 or No.2 is switched from off to on or from on to off, P0571 is detected.

Brake switch input circuit problem (P0703)

•  The PCM monitors changes in input voltage from the brake switch No.1. If the PCM does not the voltage changes while alternately accelerating and decelerating 8 times, the PCM determines that the brake switch No.1 circuit has a malfunction.

Clutch Switch

Clutch pedal position (CPP) switch input circuit problem (P0704)

•  The PCM monitors changes in input voltage from the CPP switch. If the PCM does not detect the voltage changes while the vehicle runs with vehicle speed above 30 km/h {19 mph} and stops 8 times alternately, the PCM determines that the CPP switch circuit has a malfunction.

Neutral Switch

Neutral switch input circuit problem (P0850)

•  The PCM monitors changes in input voltage from the neutral switch. If the PCM does not detect the voltage changes while driving the vehicle at a vehicle speed above 30 km/h {19 mph} and clutch pedal turns press and depress 10 times repeatedly, the PCM determines that the neutral switch circuit has a malfunction

Variable Tumble Control System

Variable tumble solenoid valve circuit low input (P2009)

•  The PCM monitors variable tumble solenoid valve control signal. If the PCM turns variable tumble solenoid valve off but voltage still remains low, the PCM determines that variable tumble solenoid valve circuit has a malfunction.

Variable tumble solenoid valve circuit high input (P2010)

•  The PCM monitors the variable tumble solenoid valve control signal. If the PCM turns variable tumble solenoid valve on but the voltage still remains high, the PCM determines that the variable tumble solenoid valve circuit has a malfunction.

Oil Control Valve

Oil control valve (OCV) circuit low (P2088)

•  The PCM monitors the OCV voltage. If the PCM detects the OCV control voltage (calculated from the OCV) is below the threshold voltage (calculated from the battery positive voltage), the PCM determines that the OCV circuit has a malfunction.

Oil control valve (OCV) circuit high (P2089)

•  The PCM monitors the OCV voltage. If the PCM detects that the OCV control voltage (calculated from the OCV) is above the threshold voltage (calculated from battery positive voltage), the PCM determines that the OCV circuit has a malfunction.

Fuel System

Target A/F feedback system too lean (P2096)

•  The PCM monitors the target A/F fuel trim when under the target A/F feedback control. If the fuel trim is more than the specification, the PCM determines that the target A/F feedback system is too lean.

Target A/F feedback system too rich (P2097)

•  The PCM monitors the target A/F fuel trim when under the target A/F feedback control. If the fuel trim is less than specification, the PCM determines that the target A/F feedback system is too rich.

Fuel system too lean at off idle (P2177)

•  PCM monitors short term fuel trim (SHRTFT), long term fuel trim (LONGFT) during closed loop fuel control at off-idle. If the LONGFT and the sum total of these fuel trims exceed preprogrammed criteria, the PCM determines that fuel system is too lean at off-idle.

Fuel system too rich at off idle (P2178)

•  PCM monitors short term fuel trim (SHRTFT), long term fuel trim (LONGFT) during closed loop fuel control at off-idle. If the LONGFT and the sum total of these fuel trims exceed the preprogrammed criteria, the PCM determines that fuel system is too rich at off-idle.

Fuel system too lean at idle (P2187)

•  The PCM monitors short term fuel trim (SHRTFT) and long term fuel trim (LONGFT) during closed loop fuel control at idle. If the LONGFT and the sum total of these fuel trims exceed the preprogrammed criteria, the PCM determines that fuel system is too lean at idle.

Fuel system too rich at idle (P2188)

•  PCM monitors short term fuel trim (SHRTFT), long term fuel trim (LONGFT) during closed loop fuel control at idle. If the LONGFT and the sum total of these fuel trims exceed preprogrammed criteria, the PCM determines that fuel system is too rich at idle.

Accelerator Pedal Position Sensor

Accelerator pedal position (APP) sensor No.1 circuit low input (P2122)

•  The PCM monitors the input voltage from APP sensor No.1 when the engine is running. If the input voltage is less than 0.2 V, the PCM determines that the APP sensor No.1 circuit input voltage is low.

Accelerator pedal position (APP) sensor No.1 circuit high input (P2123)

•  The PCM monitors the input voltage from APP sensor No.1 when the engine is running. If the input voltage is above 4.5 V, the PCM determines that the APP sensor No.1 circuit input voltage is high.

APP sensor No.2 circuit low input (P2127)

•  The PCM monitors the input voltage from APP sensor No.2 when the engine is running. If the input voltage is less than 0.2 V, the PCM determines that the APP sensor No.2 circuit has a malfunction.

APP sensor No.2 circuit high input (P2128)

•  The PCM monitors the input voltage from APP sensor No.2 when the engine is running. If the input voltage is more than 4.5 V, the PCM determines that the APP sensor No.2 circuit has a malfunction.

APP sensor No.1/No.2 voltage correlation problem (P2138)

•  The PCM compares the input voltage from APP sensor No.1 with the input voltage from APP sensor No.2 when the engine is running. If the difference is more than the specification, the PCM determines that there is an APP sensor No.1/No.2 angle correlation problem.

Generator

Charging system voltage problem (P2502)

•  The PCM determines that the generator output voltage is above 17 V or battery voltage is below 11 V while the engine is running.

Charging system voltage low (P2503)

•  The PCM needs more than 20 A from the generator, and determines that the generator output voltage is be below 8.5 V while the engine running.

Charging system voltage high (P2504)

•  The PCM determines that the generator output voltage is above 18.5 V or battery voltage is above 16.0 V while the engine running.

Variable air duct (VAD) solenoid valve

Variable air duct (VAD) solenoid valve circuit low input (P2676)

•  The PCM monitors the VAD solenoid valve control signal. If the PCM turns the VAD solenoid valve off but the voltage still remains low, the PCM determines that the VAD solenoid valve circuit has a malfunction.

Variable air duct (VAD) solenoid valve circuit high input (P2677)

•  The PCM monitors the VAD solenoid valve control signal. If the PCM turns the VAD solenoid valve on but the voltage still remains high, the PCM determines that the VAD solenoid valve circuit has a malfunction.