P0750
DTC P0750 SHIFT CONTROL SOLENOID VALVE A CIRCUIT MALFUNCTIONCOMPONENT LOCATION:
GENERAL DESCRIPTION
The Automatic transmission changes the gear position of the transmission by utilizing a combination of clutches and brakes, which are controlled by solenoid valves. This automatic transmission consists of a: LR (Low and Reverse Brake), 2ND (2nd Brake), UD (Under Drive Clutch), OD (Over Drive Clutch), REV (Reverse Clutch), and a RED (Reduction Brake, only for 5 speed transmissions). The LR Brake is engaged in the 1st gear and reverse gear positions.
DTC DESCRIPTION
The TCM checks the Low and Reverse Control Signal by monitoring the feedback signal from the solenoid valve drive circuit. If an unexpected signal is monitored (for example, high voltage is detected when low voltage is expected, or low voltage is detected when high voltage is expected), the TCM judges that the Low and Reverse control solenoid circuit is malfunctioning and sets this code.
DTC DETECTING CONDITION:
SPECIFICATION
Solenoid Valve for Pressure Control
^ Sensor type: Normal open 3-way
^ Operating temperature: -22-266 degrees F(-30 degrees C - 130 degrees C)
^ Frequency:
- LR, 2ND, UD, OD, RED: 61.27Hz (at the ATF temp. -200C above)
- DCC: 30.64Hz
- VFS: 600 ± 20Hzs
^ Internal resistance:
- 2.7-3.4 ohms (68 degrees F or 20 degrees C) - LR, 2ND, UD, OD, RED, DCC
- 4.35±0.35 ohms (68 degrees F or 20 degrees C) - VFS
^ Surge voltage: 56 V(except VFS)
SCHEMATIC DIAGRAM:
SIGNAL WAVEFORM:
MONITOR SCANTOOL DATA
1. Connect scan tool to data link connector(DLC).
2. Engine "ON".
3. Monitor the "LR SOL. VALVE" parameter on the scan tool.
4. Shift gear at each position.
5. Does "LR SOLENOID DUTY " follow the reference data?
YES Fault is intermittent caused by poor contact in the sensor's and/or TCM(PCM)'s connector or was repaired and TCM(PCM) memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration or damage. Repair or replace as necessary and go to "Verification of vehicle repair" procedure.
NO Go to "Terminal & connector inspection" procedure.
TERMINAL & CONNECTOR INSPECTION
1. Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES Repair as necessary and then go to "Verification of vehicle repair" procedure.
NO Go to "Power supply circuit inspection" procedure.
POWER SUPPLY CIRCUIT INSPECTION
1. Disconnect "A/T SOLENOID VALVE" connector.
2. Measure voltage between terminal "6" of the sensor harness connector and chassis ground.
3. Turn ignition switch OFF - ON.
4. Is voltage within specifications?
YES Go to "Signal circuit inspection" procedure.
NO
^ Check that A/T-20A fuse in engine room junction is installed or not blown.
^ Check for open in harness. Repair as necessary and go to "Verification of vehicle repair" procedure.
SIGNAL CIRCUIT INSPECTION
1. Check signal circuit open inspection
1) Ignition "OFF".
2) Disconnect A/T SOLENOID VALVE" connector and PCM/TCM" connector.
3) Measure resistance between terminal 11" of the ATM SOLENOID VALVE harness connector and terminal "22" of the PCM/TCM harness connector.
4) Is resistance within specifications?
YES Go to "Check signal circuit short inspection" procedure.
NO Check for open in harness. Repair as necessary and go to "Verification of vehicle repair" procedure.
2. Check signal circuit short inspection
1) Ignition "OFF".
2) Disconnect "A/T SOLENOID VALVE" connector and PCM/TCM connector.
3) Measure resistance between terminal 11" of the ATM SOLENOID VALVE harness and chassis ground.
4) Is resistance within specifications?
YES Go to "Component inspection" procedure.
NO Check for short to ground in harness. Repair as necessary and go to "Verification of vehicle repair" procedure.
COMPONENT INSPECTION
1. CHECK SOLENOID VALVE
1) Ignition "OFF".
2) Disconnect "A/T SOLENOID VALVE" connector.
3) Measure resistance between terminal "6" and terminal 11" of the ATM SOLENOID VALVE harness connector.
Specification: Approximately 2.7-3.4 ohms [20 degrees C(68 degrees F)]
4) Is resistance within specification?
YES Go to "CHECK PCM/TCM" as Wow.
NO Replace LR SOLENOID VALVE as necessary and go to "Verification of vehicle repair" procedure.
2. CHECK PCM/TCM
1) Connect scan tool to data link connector(DLC).
2) Ignition "ON" & Engine "OFF".
3) Select A/T solenoid valve actuator test and operate actuator test.
4) Can you hear operating sound for LR SOLENOID VALVE actuator testing function?
YES Go to "Verification of vehicle repair" procedure.
NO Replace PCM/TCM as necessary and go to "Verification of vehicle repair" procedure.
ACTUATOR TEST CONDITION
1. IG SWITCH ON
2. TRANSAXLE RANGE SWITCH is normal
3. P RANGE
4. Vehicle Speed 0mph(0km/h)
5. Throttle position sensor < 1V
6. IDLE SWITCH ON
7. ENGINE RPM 0
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.
2. Using a scan tool, Clear DTC.
3. Operate the vehicle within DTC Enable conditions in General information.
4. Are any DTCs present?
YES Go to the applicable troubleshooting procedure.
NO System performing to specification at this time.