SYSTEM DESCRIPTION
- SYSTEM DESCRIPTION The ECT (Electronic controlled automatic transmission/transaxle) is an automatic transmission/transaxle that electronically controls shift timing using the ECM. The ECM detects electrical signals that indicate engine and driving conditions, and controls the shift point, based on driver habits and road conditions. As a result, fuel efficiency and power transmission performance are improved. Shift shock has been reduced by controlling the engine and transmission simultaneously. In addition, the ECT has features such as follows: Diagnostic function. Fail-safe function when a malfunction occurs.
DESCRIPTION
The park/neutral position switch detects the shift lever position and sends signals to the ECM.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0705 | Any 2 or more signals of the following are ON simultaneously (2-trip detection logic) P input signal is ON. N input signal is ON. R input signal is ON. D input signal is ON. 3 input signal is ON. 2 input signal is ON. Any 2 or more signals of the following are ON simultaneously (2-trip detection logic) NSW (STAR) input signal is ON. R input signal is ON. D input signal is ON. 3 input signal is ON. 2 input signal is ON. All switches are OFF simultaneously for NSW (STAR), P, R, N, D, 3, 2 positions (2-trip detection logic). Both 1 and 2 conditions are met (2-trip detection logic) One of the following conditions are met NSW (STAR) input signal is ON. P input signal is ON. N input signal is ON. R input signal is ON. One of the following conditions are met 4 input signal is ON. L input signal is ON. | Short in park/neutral position switch circuit Park/neutral position switch ECM |
DTC DETECTION CONDITION AND TROUBLE AREA
MONITOR DESCRIPTION
These DTCs indicate a problem with the park/neutral position switch and the wire harness in the park/ neutral position switch circuit.
The park/neutral position switch detects the shift lever position and sends a signal to the ECM.
For security, the park/neutral position switch detects the shift lever position so that engine can be started only when the shift lever is in the P or N position
The park/neutral position switch sends a signal to the ECM according to the shift position (P, R, N or D).
The ECM determines that there is a problem with the switch or related parts if in receives more than 1 position signal simultaneously. The ECM will turn on the MIL and store the DTC.
The ATF (Automatic Transmission Fluid) temperature sensor converts the fluid temperature into a resistance value which is input into the ECM.
The ECM applies a voltage to the temperature sensor through ECM terminal THO1.
The sensor resistance changes with the transmission fluid temperature. As the temperature becomes higher, the sensor resistance decreases.
One terminal of the sensor is grounded so that the sensor resistance decreases and the voltage goes down as the temperature becomes higher.
The ECM calculates the fluid temperature based on the voltage signal.
Scheme 1
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0710 | (a) and (b) are detected momentarily within 0.5 sec. when neither P0712 nor P0713 is detected (1-trip detection logic) ATF temperature sensor resistance is less than 79 ohms. ATF temperature sensor resistance is more than 156 kohms. HINT: Within 0.5 sec, the malfunction switches from (a) to (b) or from (b) to (a) | Open or short in ATF temperature sensor circuit Transmission wire (ATF temperature sensor) ECM |
| P0712 | ATF temperature sensor resistance is less than 79 ohms for 0.5 sec. or more (1 -trip detection logic) | Short in ATF temperature sensor circuit Transmission wire (ATF temperature sensor) ECM |
| P0713 | ATF temperature sensor resistance is more than 156 kohms when 15 minutes or more have elapsed after the engine start DTC is detected for 0.5 sec. or more (1-trip detection logic) | Open in ATF temperature sensor circuit Transmission wire (ATF temperature sensor) ECM |
DTC DETECTION CONDITION AND TROUBLE AREA
These DTCs indicate an open or short in the automatic transmission fluid (ATF) temperature sensor (TFT sensor) circuit. The automatic transmission fluid (ATF) temperature sensor converts ATF temperature to an electrical resistance value. Based on the resistance, the ECM determines the ATF temperature, and the ECM detects an opens or shorts in the ATF temperature circuit. If the resistance value of the ATF temperature is less than 79 ohms *1 or more than 156 kohms *2 , the ECM interprets this as a fault in the ATF sensor or wiring. The ECM will turn on the MIL and store the DTC.
*1: 150°C (302°F) or more is indicated regardless of the actual ATF temperature.
*2: -40°C (-40°F) is indicated regardless of the actual ATF temperature.
HINT
The ATF temperature can be checked on the OBD II scan tool or intelligent tester display.
The ATF (Automatic Transmission Fluid) temperature sensor converts the fluid temperature into a resistance value which is input into the ECM.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0711 | Both (a) and (b) are detected: (2-trip detection logic) Intake air and engine coolant temperatures are more than -10°C (14°F) at engine start After normal driving for over 19 min. and 9 km (6 mile) or more, ATF temp, is less than 20°C (68°F) When engine coolant temp, is less than 35°C (95°F) at engine start, the ATF temp, is 110°C (230°F) or more after 17 min. of engine start (2-trip detection logic). | Transmission wire (ATF temperature sensor) |
DTC DETECTION CONDITION AND TROUBLE AREA
The ATF temperature sensor converts the ATF temperature to an electrical resistance value. Based on the resistance, the ECM determines the ATF temperature and detects an open or short in the ATF temperature circuit or a fault in the ATF temperature sensor.
After running the vehicle for a certain period, the ATF temperature should increase. If the ATF temperature is below 20°C (68°F) after running the vehicle for a certain period, the ECM interprets this as a fault, and turns on the MIL.
When the ATF temperature is 110°C (230°F) or more after 17 minutes of engine cold start, the ECM also determines this as a fault, turns on the MIL, and stores the DTC.
This sensor detects the rotation speed of the input turbine. By comparing the input turbine speed signal (NT) with the counter gear speed sensor signal (NC), the ECM detects the shift timing of the gears and appropriately controls the engine torque and hydraulic pressure according to various conditions. Thus, providing smooth gear shift.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0717 | ECM detects conditions (a), (b) and (c) continuously for 5 sec. or more: (1-trip detection logic) Vehicle speed: 50 km/h (31 mph) or more Park/neutral position switch (NSW (STAR) and R) is OFF Speed sensor (NT): less than 300 rpm | Open or short in transmission revolution sensor NT (speed sensor NT) circuit Transmission revolution sensor NT (speed sensor NT) ECM Automatic transaxle assembly |
DTC DETECTION CONDITION AND TROUBLE AREA
Reference (Using an oscilloscope)
Check the waveform between terminals NT+ and NT- of the ECM connector.
Standard: Refer to the illustration.
| Terminal | NT+ - NT |
|---|---|
| Tool setting | 5 V/DIV., 0.5 ms./DIV. |
| Vehicle condition | Vehicle speed 20 km/h (12 mph) |
WAVEFORM REFERENCE
The NT terminal of the ECM detects a revolution signal from the speed sensor (NT) (input RPM). The ECM calculates a gearshift comparing the speed sensor (NT) with the speed sensor (NC).
While the vehicle is operating in 2nd, 3rd, 4th or 5th gear in the shift position of D, if the input shaft revolution is less than 300 rpm *1 although the output shaft revolution is more than 1,000 rpm *2 , the ECM detects the trouble, illuminates the MIL and stores the DTC.
*1: Pulse is not output or is irregularly output.
*2: The vehicle speed is 50 km/h (31 mph) or more.
The purpose of this circuit is to prevent the engine from stalling while driving in lock-up condition when brakes are suddenly applied.
When the brake pedal is depressed, this switch sends a signals to the ECM. Then the ECM cancels the operation of the lock-up clutch while braking is in progress.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0724 | The stop light switch remains ON even when the vehicle is driven in a STOP (less than 3 km/h (2 mph) and GO (30 km/h (19 mph) or more) fashion 5 times. (2-trip detection logic). | Short in stop light switch circuit Stop light switch ECM |
DTC DETECTION CONDITION AND TROUBLE AREA
This DTC indicates that the stop light switch remains on. When the stop light switch remains ON during "stop and go" driving, the ECM interprets this as a fault in the stop light switch and the MIL comes on and the ECM stores the DTC. The vehicle must stop (less than 3 km/h (2 mph)) and go (30 km/h (19 mph) or more) 5 times for two driving cycles in order to detect a malfunction.
The ECM uses the signals from the throttle position sensor, air-flow meter, turbine (input) speed sensor, intermediate (counter) shaft speed sensor and crankshaft position sensor to monitor the engagement condition of the lock-up clutch.
Then the ECM compares the engagement condition of the lock-up clutch with the lock-up schedule in the ECM memory to detect a mechanical problems of the shift solenoid valve DSL, valve body and torque converter clutch.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0741 | Lock-up does not occur when driving in the lock-up range (normal driving at 80 km/h [50 mph]), or lock up remains ON in the lock-up OFF range. (2-trip detection logic) | Shift solenoid valve DSL remains open or closed Valve body is blocked Torque converter clutch Automatic transaxle (clutch, brake or gear etc.) Line pressure is too low |
DTC DETECTION CONDITION AND TROUBLE AREA
Torque converter lock-up is controlled by the ECM based on the speed sensor (NT), speed sensor (NC), engine rpm, engine load, engine temperature, vehicle speed, transmission temperature, and gear selection. The ECM determines the lock-up status of the torque converter by comparing the engine rpm (NE) to the input turbine rpm (NT). The ECM calculates the actual transmission gear by comparing input turbine rpm (NT) to counter gear rpm (NC). When conditions are appropriate, the ECM requests "lock-up" by applying control voltage to the shift solenoid DSL. When the DSL is turned on, it applies pressure to the lock-up relay valve and locks the torque converter clutch.
If the ECM detects no lock-up after lock-up has been requested or if it detects lock-up when it is not requested, the ECM interprets this as a fault in the shift solenoid valve DSL or lock-up system performance. The ECM will turn on the MIL and store the DTC.
HINT
Example
When any of the following is met, the system judges it as a malfunction.
- There is a difference in rotation between the input side (engine speed) and output side (input turbine speed) of the torque converter when the ECM commands lock-up. (Engine speed is at least 100 rpm greater than input turbine speed.)
- There is no difference in rotation between the input side (engine speed) and output side (input turbine speed) of the torque converter when the ECM commands lock-up off. (The difference between engine speed and input turbine speed is less than 35 rpm.)
The ECM uses signals from the vehicle speed sensor to detect the actual gear position (1st, 2nd, 3rd, 4th or 5th gear).
Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical problems of the shift solenoid valves, valve body or automatic transaxle (clutch, brake or gear etc.).
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0746 | The gear required by the ECM does not match the actual gear when driving (2-trip detection logic) | Shift solenoid valve SL1 remains open or closed Valve body is blocked Automatic transaxle (clutch, brake or gear etc.) |
DTC DETECTION CONDITION AND TROUBLE AREA
The ECM commands gear shifts by turning the shift solenoid valves "ON/OFF". According to the input shaft revolution, intermediate (counter) shaft revolution and output shaft revolution, the ECM detects the actual gear position (1st, 2nd, 3rd, 4th or 5th gear position). When the gear position commanded by the ECM and the actual gear position are not the same, the ECM illuminates the MIL.
HINT
Example
When either condition (a) or (b) is met, the ECM detects a malfunction.
- The ECM commands the 1st gear, but the actual gear is 2nd.
- The ECM commands the 2nd gear, but the actual gear is 1st.
Shifting from 1st to 5th is performed in combination with "ON" and "OFF" operation of the shift solenoid valves SL1, SL2, SL3, S4 and SR which are controlled by the ECM. If an open or short circuit occurs in either of the shift solenoid valves, the ECM controls the remaining normal shift solenoid valves to allow the vehicle to be operated smoothly (Fail safe function).
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0748 | The ECM checks for an open or short in the shift solenoid valve SL1 circuit while driving and shift gears. {1 -trip detection logic) Output signal duty equals to 100 %. (NOTE: SL1 output signal duty is less than 100 % under normal condition.) | Open or short in shift solenoid valve SL1 circuit Shift solenoid valve SL1 ECM |
DTC DETECTION CONDITION AND TROUBLE AREA
The ECM commands gear shifts by turning the shift solenoid valves "ON/OFF". When there is an open or short circuit in any shift solenoid valve circuit, the ECM detects the problem and illuminates the MIL and stores the DTC. And the ECM performs the fail-safe function and turns the other normal shift solenoid valves "ON/OFF" (In case of an open or short circuit, the ECM stops sending current to the circuit.) (See DATA LIST / ACTIVE TEST ).
The ECM uses signals from the vehicle speed sensor to detect the actual gear position (1st, 2nd, 3rd, 4th or 5th gear).
Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical problems of the shift solenoid valves, valve body or automatic transaxle (clutch, brake or gear etc.).
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0766 | The gear required by the ECM does not match the actual gear when driving (2-trip detection logic) | Shift solenoid valve S4 remains open or closed Valve body is blocked Automatic transaxle (clutch, brake or gear etc.) |
DTC DETECTION CONDITION AND TROUBLE AREA
The ECM commands gear shifts by turning the shift solenoid valves "ON/OFF". According to the input shaft revolution, intermediate (counter) shaft revolution and output shaft revolution, the ECM detects the actual gear position (1st, 2nd, 3rd, 4th or 5th gear position). When the gear position commanded by the ECM and the actual gear position are not the same, the ECM illuminates the MIL and stores the DTC.
The ECM uses signals from the vehicle speed sensor to detect the actual gear position (1st, 2nd, 3rd, 4th or 5th gear).
Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical problems of the shift solenoid valves, valve body or automatic transaxle (clutch, brake or gear etc.).
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0771 | The gear required by the ECM does not match the actual gear when driving (2-trip detection logic) | Shift solenoid valve SR remains open or closed Valve body is blocked Automatic transaxle (clutch, brake or gear etc.) |
DTC DETECTION CONDITION AND TROUBLE AREA
The ECM commands gear shifts by turning the shift solenoid valves "ON/OFF". According to the input shaft revolution, intermediate (counter) shaft revolution and output shaft revolution, the ECM detects the actual gear position (1st, 2nd, 3rd, 4th or 5th gear position). When the gear position commanded by the ECM and the actual gear position are not the same, the ECM illuminates the MIL and stores the DTC.
The ECM uses signals from the vehicle speed sensor to detect the actual gear position (1st, 2nd, 3rd, 4th or 5th gear).
Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical problems of the shift solenoid valves, valve body or automatic transaxle (clutch, brake or gear etc.).
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0776 | The gear required by the ECM does not match the actual gear when driving (2-trip detection logic) | Shift solenoid valve SL2 remains open or closed Valve body is blocked Automatic transaxle (clutch, brake or gear etc.) |
DTC DETECTION CONDITION AND TROUBLE AREA
The ECM commands gear shifts by turning the shift solenoid valves "ON/OFF". According to the input shaft revolution, intermediate (counter) shaft revolution and output shaft revolution, the ECM detects the actual gear position (1st, 2nd, 3rd, 4th or 5th gear position). When the gear position commanded by the ECM and the actual gear position are not the same, the ECM illuminates the MIL and stores the DTC.
Shifting from 1st to 5th is performed in combination with "ON" and "OFF" operation of the shift solenoid valves SL1, SL2, SL3, S4 and SR which are controlled by the ECM. If an open or short circuit occurs in either of the shift solenoid valves, the ECM controls the remaining normal shift solenoid valves to allow the vehicle to be operated smoothly (Fail safe function).
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0778 | ECM checks for an open or short circuit in shift solenoid valves SL2 (1-trip detection logic) Hybrid IC for solenoid indicates fail. | Open or short in shift solenoid valve SL2 circuit Shift solenoid valve SL2 ECM |
DTC DETECTION CONDITION AND TROUBLE AREA
The ECM commands gear shifts by turning the shift solenoid valves "ON/OFF". When there is an open or short circuit in any shift solenoid valve circuit, the ECM detects the problem and illuminates the MIL and stores the DTC. And the ECM performs the fail-safe function and turns the other normal shift solenoid valves "ON/OFF" (In case of an open or short circuit, the ECM stops sending current to the circuit.) (See DATA LIST / ACTIVE TEST ).
This sensor detects the rotation speed of the counter gear. By comparing the counter gear speed signal (NC) with the direct clutch speed sensor signal (NT), the ECM detects the shift timing of the gears and appropriately controls the engine torque and hydraulic pressure according to various conditions. Thus smooth gear shifting is performed.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0793 | ECM detects conditions (a), (b) and (c) continuously for 5 sec. or more: (1-trip detection logic) Vehicle speed: 50 km/h (31 mph) or more Park/neutral position switch (NSW (STAR)) is OFF Speed sensor (NC): less than 300 rpm | Open or short in transmission revolution sensor NC (speed sensor NC) circuit Transmission revolution sensor NC (speed sensor NC) ECM |
DTC DETECTION CONDITION AND TROUBLE AREA
Reference (Using an oscilloscope)
Check the waveform between terminals NC+ and NC- of the ECM connector.
Scheme 2
Standard: Refer to the illustration.
| Terminal | NC+-NC |
|---|---|
| Tool setting | 1 V/DIV, 1ms./DIV |
| Vehicle condition | Vehicle speed 30 km/h (19 mph): (3rd gear) Engine speed 1,400 rpm |
WAVEFORM REFERENCE
The NC terminal of the ECM detects a revolution signal from the speed sensor (NC) (counter gear rpm). The ECM calculates a gearshift comparing the speed sensor (NT) with the speed sensor (NC). While the vehicle is operating in 2nd, 3rd, 4th or 5th gear in the shift position of D, if the counter gear revolution is less than 300 rpm *1 although the output shaft revolution is more than 1,000 rpm *2 , the ECM detects the trouble, illuminates the MIL and stores the DTC.
*1: Pulse is not output or is irregularly output.
*2: The vehicle speed is 50 km/h (31 mph) or more.
The ECM uses signals from the vehicle speed sensor to detect the actual gear position (1st, 2nd, 3rd, 4th or 5th gear).
Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical troubles of the shift solenoid valves and valve body.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0796 | The gear required by the ECM does not match the actual gear when driving (2-trip detection logic) | Shift solenoid valve SL3 remains open or closed Valve body is blocked Automatic transaxle (clutch, brake or gear etc.) |
DTC DETECTION CONDITION AND TROUBLE AREA
The ECM commands gear shifts by turning the shift solenoid valves "ON/OFF". According to the input shaft revolution, intermediate (counter) shaft revolution and output shaft revolution, the ECM detects the actual gear position (1st, 2nd, 3rd, 4th or 5th gear position). When the gear position commanded by the ECM and the actual gear position are not the same, the ECM illuminates the MIL and stores the DTC.
Shifting from 1st to 5th is performed in combination with "ON" and "OFF" operation of the shift solenoid valves SL1, SL2, SL3, S4 and SR which are controlled by the ECM. If an open or short circuit occurs in either of the shift solenoid valves, the ECM controls the remaining normal shift solenoid valves to allow the vehicle to be operated smoothly (Fail safe function).
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0798 | The ECM checks for an open or short in the shift solenoid valve SL3 circuit while driving and shifting gears. (1-trip detection logic) Output signal duty equals to 100 %. (NOTE: SL3 output signal duty is less than 100 % under normal condition.) | Open or short in shift solenoid valve SL3 circuit Shift solenoid valve SL3 ECM |
DTC DETECTION CONDITION AND TROUBLE AREA
The ECM commands gear shifts by turning the shift solenoid valves "ON/OFF". When there is an open or short circuit in any shift solenoid valve circuit, the ECM detects the problem and illuminates the MIL and stores the DTC. And the ECM performs the fail-safe function and turns the other normal shift solenoid valves "ON/OFF" (In case of an open or short circuit, the ECM stops sending current to the circuit.) (See DATA LIST / ACTIVE TEST ).
Shifting from 1st to 5th is performed in combination with "ON" and "OFF" operation of the shift solenoid valves SL1, SL2, SL3, S4 and SR which are controlled by the ECM. If an open or short circuit occurs in either of the shift solenoid valves, the ECM controls the remaining normal shift solenoid valves to allow the vehicle to be operated smoothly (Fail safe function).
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0982 | ECM detects short in solenoid valve S4 circuit 2 times when solenoid valve S4 is operated (1-trip detection logic) | Short in shift solenoid valve S4 circuit Shift solenoid valve S4 ECM |
| P0983 | ECM detects open in solenoid valve S4 circuit 2 times when solenoid valve S4 is not operated (1-trip detection logic) | Open in shift solenoid valve S4 circuit Shift solenoid valve S4 ECM |
DTC DETECTION CONDITION AND TROUBLE AREA
The ECM commands gear shifts by turning the shift solenoid valves "ON/OFF". When there is an open or short circuit in any shift solenoid valve circuit, the ECM detects the problem and illuminates the MIL and stores the DTC. And the ECM performs the fail-safe function and turns the other normal shift solenoid valves "ON/OFF" (In case of an open or short circuit, the ECM stops sending current to the circuit.) (See DATA LIST / ACTIVE TEST ).
Shifting from 1st to 5th is performed in combination with "ON" and "OFF" operation of the shift solenoid valves SL1, SL2, SL3, S4 and SR which are controlled by the ECM. If an open or short circuit occurs in either of the shift solenoid valves, the ECM controls the remaining normal shift solenoid valves to allow the vehicle to be operated smoothly (Fail safe function).
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0985 | ECM detects short in solenoid valve SR circuit 2 times when solenoid valve SR is operated (1-trip detection logic) | Short in shift solenoid valve SR circuit Shift solenoid valve SR ECM |
| P0986 | ECM detects open in solenoid valve SR circuit 2 times when solenoid valve SR is not operated (1-trip detection logic) | Open in shift solenoid valve SR circuit Shift solenoid valve SR ECM |
DTC DETECTION CONDITION AND TROUBLE AREA
The ECM commands gear shifts by turning the shift solenoid valves "ON/OFF". When there is an open or short circuit in any shift solenoid valve circuit, the ECM detects the problem and illuminates the MIL and stores the DTC. And the ECM performs the fail-safe function and turns the other normal shift solenoid valves "ON/OFF" (In case of an open or short circuit, the ECM stops sending current to the circuit.) (See DATA LIST / ACTIVE TEST ).
The linear solenoid valve (SLT) controls the transmission line pressure for smooth transmission operation based on signals from the throttle position sensor and the vehicle speed sensor. The ECM adjusts the duty ratio (*) of the SLT solenoid valve to control hydraulic line pressure coming from the primary regulator valve. Appropriate line pressure assures smooth shifting with varying engine outputs.
(*): Duty Ratio
The duty ratio is the ratio of the period of continuity in one cycle. For example, if A is the period of continuity in one cycle, and B is the period of non-continuity, then Duty Ratio=A/(A+B) x 100(%)
Scheme 3
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P2714 | ECM detects a malfunction on SLT (ON side) according to the revolution difference of the turbine, intermediate and the output shaft, and also by the oil pressure. (2-trip detection logic) | Shift solenoid valve SLT remains closed Valve body is blocked Automatic transaxle (clutch, brake or gear, etc.) |
DTC DETECTION CONDITION AND TROUBLE AREA
In any forward position, when the difference between the revolutions of the turbine, Intermediate and output shaft exceeds the specified value (varies with Intermediate, output speed) determined by the ECM, the ECM illuminates the MIL and store the DTC.
When shift solenoid valve SLT remains on, the oil pressure goes down and the clutch engagement force decreases.
Note. If you continue driving under these conditions, the clutch will burn out and the vehicle will no longer be drivable.
The linear solenoid valve (SLT) controls the transmission line pressure for smooth transmission operation based on signals from the throttle position sensor and the vehicle speed sensor. The ECM adjusts the duty cycle of the SLT solenoid valve to control hydraulic line pressure coming from the primary regulator valve. Appropriate line pressure assures smooth shifting with varying engine outputs.
(*): Duty Ratio
The duty ratio is the ratio of the period of continuity in one cycle.
For example, if A is the period of continuity in one cycle, and B is the period of non-continuity, then Duty Ratio = A/(A + B) x 100(%)
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P2716 | Open or short is detected in shift solenoid valve SLT circuit for 1 second or more while driving (1-trip detecting logic). | Open or short in shift solenoid valve SLT circuit Shift solenoid valve SLT ECM |
DTC DETECTION CONDITION AND TROUBLE AREA
Scheme 4
When an open or short in the linear solenoid valve (SLT) circuit is detected, the ECM interprets this as a fault. The ECM will turn on the MIL and store the DTC.
The shift solenoid valve DSL is turned "ON" and "OFF" by signals from the ECM in order to control the hydraulic pressure operation, the lock-up relay valve, which then controls operation of the lock-up clutch.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P2769 | ECM detects short in solenoid valve DSL circuit (0.1 sec.) when solenoid valve DSL is operated (2-trip detection logic) | Short in shift solenoid valve DSL circuit Shift solenoid valve DSL ECM |
| P2770 | ECM detects open in solenoid valve DSL circuit (0.1 sec.) when solenoid valve DSL is not operated (2-trip detection logic) | Open in shift solenoid valve DSL circuit Shift solenoid valve DSL ECM |
DTC DETECTION CONDITION AND TROUBLE AREA
Torque converter lock-up is controlled by the ECM based on engine rpm, engine load, engine temperature, vehicle speed, transmission temperature, and shift range selection. The ECM determines the lock-up status of the torque converter by comparing the engine rpm (NE) to the input turbine rpm (NT). The ECM calculates the actual transmission gear by comparing input turbine rpm (NT) to counter gear rpm (NC). When conditions are appropriate, the ECM requests "lock-up" by applying control voltage to the shift solenoid DSL. When the DSL is opened, it applies pressure to the lock-up relay valve and locks the torque converter clutch. If the ECM detects an open or short in the DSL solenoid circuit, the ECM interprets this as a fault in the DSL solenoid or circuit. The ECM will turn on the MIL and store the DTC.
See also:
• REGISTRATION