DTC P177A
DTC P177A : Line Pressure Solenoid Valve A Or Line Pressure Switch Stuck OFF
| DTC Description | Confirmed DTC | Pending DTC | Freeze Frame |
|---|---|---|---|
| P177A Line Pressure Solenoid Valve A Or Line Pressure Switch Stuck OFF |
DTC (A/T)
- ATF check
-1. Warm up the engine to normal operating temperature (the radiator fan comes on).
-2. Make sure that the transmission is filled to the proper level, and check for fluid leaks.
-3. Drain the ATF through a strainer. Inspect the strainer for metal debris or excessive clutch material.
Does the strainer have metal debris or excessive clutch material?
YES
NO
Replace the ATF , then go to step 2.
- Problem verification
-1. Raise the vehicle on a lift. Make sure it is securely supported, and allow all four wheels to rotate freely.
-2. Turn the vehicle to the ON mode.
-3. Clear the DTC with the HDS.
-4. Start the engine.
-5. Monitoring the APP Sensor (%) with the HDS, press (2 % opened) and release (0 % opened) the accelerator pedal every 2 seconds. Then check the Line Pressure Sol VLV. A signal and the Line Pressure Switch signal with the HDS.
Signal Current conditions Values Unit APP Sensor (%) Line Pressure Sol VLV. A Line Pressure Switch Is the Line Pressure Switch ON when Line Pressure Sol VLV. A is ON, and OFF when Line Pressure Sol VLV. A is OFF?
YES
Intermittent failure, the system is OK at this time. Check for poor connections and loose terminals between the line pressure switch and the PCM.
NO
The failure is duplicated. Go to step 3.
- Determine possible failure area (IG1(VBSOL) line, others)
-1. Select the Line Pressure Solenoid Test in the Miscellaneous Test Menu, and check that line pressure solenoid valve A operates with the HDS.
Line Pressure Solenoid Test
Is a clicking sound heard?
YES
Go to step 6.
NO
Go to step 4.
- Fuse check
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Check the following fuse.
Fuse No. C1 (15 A) Location Under-hood fuse/relay box Is the fuse OK?
YES
The fuse is OK. Go to step 5.
NO
Replace the No. C1 (15 A) fuse, and recheck. If the fuse blows again, repair a short to ground on the No. C1 (15 A) fuse circuit, and recheck.
- Open wire check (IG1(VBSOL) line)
-1. Jump the SCS line with the HDS.
-2. Disconnect the following connector.
PCM connector B (51P) -3. Turn the vehicle to the ON mode.
-4. Measure the voltage between test points 1 and 2.
Test condition Vehicle ON mode PCM connector B (51P): disconnected Test circuit IG1(VBSOL) Test point 1 PCM connector B (51P) No. 1 (TAN) Test point 2 Body ground Is there battery voltage?
YES
The IG1(VBSOL) wire is OK. Faulty line pressure solenoid valve A. Replace the secondary valve body (line pressure solenoid valve A) .
NO
Repair an open in the IG1(VBSOL) wire between the PCM and the No. C1 (15 A) fuse in the under-hood fuse/relay box.
- Line pressure switch check
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Disconnect the following connector.
Line pressure switch 1P connector -3. Connect terminals A and B with a jumper wire.
Terminal A Line pressure switch 1P connector No. 1 (BRN) Terminal B Body ground -4. Turn the vehicle to the ON mode.
-5. Check the parameter(s) below with the HDS.
Signal Threshold Current conditions Values Unit Values Unit Line Pressure Switch ON Do the current condition(s) match the threshold?
YES
Replace the line pressure switch .
NO
The line pressure switch is OK. Go to step 7.
- Open wire check (OPPLSW line)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Remove the jumper wire.
-3. Jump the SCS line with the HDS.
-4. Disconnect the following connector.
PCM connector B (51P) -5. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Line pressure switch 1P connector: disconnected PCM connector B (51P): disconnected Test circuit OPPLSW Test point 1 Line pressure switch 1P connector No. 1 (BRN) Test point 2 PCM connector B (51P) No. 37 (BRN) Is there continuity?
YES
The OPPLSW wire is OK. Replace the PCM .
NO
Repair an open in the OPPLSW wire between the line pressure switch and the PCM.