CONTINUOUSLY VARIABLE TRANSMISSION (DIAGNOSTICS) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)
DTC P0746 PRESSURE CONTROL SOLENOID "A" PERFORMANCE/STUCK OFF
DTC detecting condition:
Detected when two consecutive driving cycles with fault occur.
Trouble symptom:
• Shift control malfunction
• CVT chain slippage
Wiring diagram:
CVT control system CVT Control System">
STEP | CHECK | YES | NO |
1.CHECK DTC.
Read the DTC using Subaru Select Monitor.
Besides DTC P0746, is any of the DTCs P0842, P0843, P0962 and P0963 displayed?
Perform the diagnosis according to DTCs other than P0746.
Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0746 PRESSURE CONTROL SOLENOID "A" PERFORMANCE/STUCK OFF">Go to Step 2.
2.CHECK SECONDARY SOLENOID (ACTIVE TEST).
1) Turn the ignition switch to ON.
2) Using the Subaru Select Monitor, perform forced operation of the secondary solenoid. Active Test">
Does the indication of 0 > 500 mA appear repeatedly during forced operation, and does operating sound emit during indicating 500 mA?
Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0746 PRESSURE CONTROL SOLENOID "A" PERFORMANCE/STUCK OFF">Go to Step 5.
Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0746 PRESSURE CONTROL SOLENOID "A" PERFORMANCE/STUCK OFF">Go to Step 3.
3.CHECK SECONDARY SOLENOID.
1) Turn the ignition switch to OFF.
2) Disconnect the transmission connector.
3) Measure the resistance between transmission connector and transmission body.
Connector & terminal
(T4) No. 6 — Transmission body:
Is the resistance approx. 5 — 7 ?? (when cold)
Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0746 PRESSURE CONTROL SOLENOID "A" PERFORMANCE/STUCK OFF">Go to Step 7.
Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0746 PRESSURE CONTROL SOLENOID "A" PERFORMANCE/STUCK OFF">Go to Step 4.
4.CHECK HARNESS.
Check the transmission harness. (Open circuit, short circuit to power supply, short circuit to ground, and poor contact)
Is the check result OK?
Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0746 PRESSURE CONTROL SOLENOID "A" PERFORMANCE/STUCK OFF">Go to Step 7.
Repair the harness.
5.CHECK TRANSMISSION FLUID.
1) Connect the transmission connector.
2) Check the amount of ATF. CVTF > ADJUSTMENT">
Is the check result OK?
Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0746 PRESSURE CONTROL SOLENOID "A" PERFORMANCE/STUCK OFF">Go to Step 6.
Adjust the amount of ATF. CVTF > ADJUSTMENT">
6.CHECK TRANSMISSION FLUID.
Check the condition of ATF. CVTF > CONDITION CHECK">
Is the check result OK?
Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0746 PRESSURE CONTROL SOLENOID "A" PERFORMANCE/STUCK OFF">Go to Step 7.
Check according to the “Corrective action” of ATF (CVTF) “CONDITION CHECK”. CVTF > CONDITION CHECK">
7.CHECK INPUT SIGNAL FOR TCM.
1) Lift up the vehicle.
2) Start the engine.
3) Warm up until the ATF temperature reaches to 40 — 70°C (104 — 158°F).
4) Depress the brake pedal, and shift the select lever to “D” range.
5) Shift the select lever to “P” range.
6) Stabilize the engine speed at idle.
7) Read the data of «Actual Secondary Pressure» using Subaru Select Monitor.
Is the «Actual Secondary Pressure» 0.5 — 1.5 MPa?
Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0746 PRESSURE CONTROL SOLENOID "A" PERFORMANCE/STUCK OFF">Go to Step 8.
Replace the control valve body. Control Valve Body">
8.CHECK INPUT SIGNAL FOR TCM.
1) Keep the engine speed at 3,000 rpm.
2) Read the data of «Actual Secondary Pressure» using Subaru Select Monitor.
Is the «Actual Secondary Pressure» higher than step 7 value? Does the value change according to the engine speed, within the range of 1.5 — 2.5 MPa?
Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0746 PRESSURE CONTROL SOLENOID "A" PERFORMANCE/STUCK OFF">Go to Step 9.
Replace the control valve body. Control Valve Body">
9.CHECK TCM INPUT SIGNAL (STALL TEST).
1) Apply the parking brake.
2) Set the select lever to “D” range.
3) Depress the brake pedal firmly.
4) Slowly open the accelerator fully, and stabilize the engine speed.
5) Read the data of «Actual Secondary Pressure» using Subaru Select Monitor.
CAUTION:
Do not perform a stall test for over 5 seconds at a time.
Is the «Actual Secondary Pressure» higher than step 8 value? Does the value change according to the engine speed, within the range of 4.5 — 6.0 MPa?
Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0746 PRESSURE CONTROL SOLENOID "A" PERFORMANCE/STUCK OFF">Go to Step 10.
Replace the control valve body. Control Valve Body">
10.DRIVING CHECK BY INSPECTION MODE.
1) Turn the ignition switch to OFF.
2) Perform a drive check based on the “Inspection Mode”. Inspection Mode">
Does the AT OIL TEMP light blink and is DTC P0746 displayed?
Perform the secondary pressure test. Secondary Pressure (Line Pressure) Test">
Current condition is normal. It is possible that temporary poor contact occurs.
1. OUTLINE OF DIAGNOSIS
• Detect the malfunction of transmission line pressure solenoid and hydraulic circuit (stuck to low pressure side).
• Judge as NG if “Target line pressure − Actual line pressure” becomes the predetermined value or more, while the actual line pressure is equal to or more than the predetermined value.
2. EXECUTION CONDITION
Secondary Parameters | Execution condition |
12 V battery system voltage | ≥ 10 V |
Engine speed | ≥ 1000 rpm |
Measured line pressure control solenoid valve current | ≤ 0.78 A |
3. DIAGNOSTIC METHOD
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Malfunction Criteria | Threshold Value |
Measured line pressure | < Map1 kPa |
Engine speed (rpm) | ||||||||
0 | 500 | 1000 | 1500 | 2000 | 2500 | 3000 | ||
Transmission fluid temperature (degC) | − 40 | 0 | 0 | 340 | 404 | 478 | 558 | 643 |
− 20 | 0 | 0 | 340 | 404 | 478 | 558 | 643 | |
0 | 0 | 0 | 324 | 382 | 454 | 532 | 616 | |
20 | 0 | 0 | 366 | 425 | 490 | 565 | 649 | |
40 | 0 | 0 | 345 | 400 | 466 | 536 | 613 | |
60 | 0 | 0 | 341 | 389 | 447 | 512 | 591 | |
80 | 0 | 0 | 319 | 371 | 429 | 488 | 571 | |
100 | 0 | 0 | 298 | 356 | 412 | 476 | 551 | |
120 | 0 | 0 | 271 | 329 | 384 | 451 | 519 | |
140 | 0 | 0 | 243 | 302 | 357 | 425 | 487 |
Engine speed (rpm) | ||||||||
3500 | 4000 | 4500 | 5000 | 5500 | 6000 | 6500 | ||
Transmission fluid temperature (degC) | − 40 | 751 | 883 | 1042 | 1167 | 1264 | 1292 | 1274 |
− 20 | 751 | 883 | 1042 | 1167 | 1264 | 1342 | 1424 | |
0 | 722 | 840 | 991 | 1135 | 1240 | 1319 | 1395 | |
20 | 751 | 861 | 1000 | 1160 | 1258 | 1350 | 1417 | |
40 | 708 | 817 | 943 | 1103 | 1223 | 1312 | 1385 | |
60 | 677 | 779 | 906 | 1064 | 1187 | 1266 | 1339 | |
80 | 652 | 748 | 874 | 1000 | 1135 | 1223 | 1299 | |
100 | 629 | 719 | 831 | 947 | 1069 | 1181 | 1251 | |
120 | 593 | 678 | 780 | 880 | 990 | 1109 | 1171 | |
140 | 557 | 637 | 728 | 813 | 911 | 1037 | 1090 |
Time Needed for Diagnosis: 5 seconds
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.
Precautions against vehicle modification
Always consult your SUBARU dealer if
you want to install any accessory parts to
your vehicle.
CAUTION
Do not perform any of the following
modifications. Such modifications
can interfere with proper operation
of the seatbelt pretensioners.
Attachment of any equipment
(bush bar, winches, ...
Dtc b28a6 internal stereo camera communication 1
EyeSight (DIAGNOSTICS) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)DTC B28A6 INTERNAL STEREO CAMERA COMMUNICATION 1Detected when communication error occurs inside the stereo camera.DTC DETECTING CONDITION:Communication error occurs inside the stereo camera.TROUBLE SYMPTOM:All functio ...
Removal
SECURITY AND LOCKS > IG Relay2 (Push Button Start)REMOVALCAUTION:Before handling the airbag system components, refer to “CAUTION” of “General Description” in “AIRBAG SYSTEM”. General Description > CAUTION">1. Disconnect the ground cable from battery ...