DTC P177A: Line Pressure Solenoid Valve A Stuck OFF, or Line Pressure Switch Stuck OFF
- Warm up the engine to normal operating temperature (the radiator fan comes on).
- Make sure that the transmission is filled to the proper level, and check for fluid leaks.
- Drain the ATF (see ATF REPLACEMENT
) through a strainer. Inspect the strainer for metal debris or excessive clutch material.
Does the strainer have metal debris or excessive clutch material?
YES - Replace the transmission.
NO - Replace the ATF (see ATF REPLACEMENT ), then go to step 4.
- With SH-AWD: Raise the vehicle on a lift, make sure it is securely supported, and allow all four wheels to rotate freely.
Without SH-AWD: Block the rear wheels, and raise the front of the vehicle, make sure it is securely supported, and allow the front wheels to rotate freely, or raise the vehicle on a lift.
- Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
- Clear the DTC with the HDS.
- Start the engine. With the brake pedal pressed, shift to D, then release the brake pedal.
- Monitoring the APP Sensor (%) with the HDS in the A/T Data List, 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 Pressure Switch signal with the HDS in the A/T Data List.
Is the Line Pressure 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 - Go to step 9.
- Select Line Pressure Solenoid A in the Miscellaneous Test Menu, and check that line pressure solenoid valve A operates with the HDS.
Is a clicking sound heard?
YES - Go to step 16.
NO - Go to step 10.
- Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
- Check for a blown No. 13 (15 A) fuse in the driver's under-dash fuse/relay box.
Is the No. 13 (15 A) fuse OK?
YES - Go to step 12.
NO - Repair a short to body ground in the wire between PCM connector terminal B2 and the driver's under-dash fuse/relay box.
- Jump the SCS line with the HDS.
- Disconnect PCM connector B (49P).
- Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
- Measure the voltage between PCM connector terminal B2 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES - Faulty line pressure solenoid valve A. Replace the secondary valve body (line pressure solenoid valve A) (see SECONDARY VALVE BODY REPLACEMENT ).
NO - Repair an open in the wire between PCM connector terminal B2 and the driver's under-dash fuse/relay box.
- Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
- Disconnect the line pressure switch connector.
- Connect a jumper wire between the line pressure switch connector terminal and body ground.
- Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
- Check the Line Pressure Pressure Switch signal with the HDS in the A/T Data List.
Is the Line Pressure Pressure Switch ON?
YES - Replace the line pressure switch (see LINE PRESSURE SWITCH REPLACEMENT ).
NO - Go to step 21.
- Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
- Remove the jumper wire.
- Jump the SCS line with the HDS.
- Disconnect PCM connector C (49P).
- Check for continuity between PCM connector terminal C35 and the line pressure switch connector terminal.Fig 3: Checking Continuity Between PCM Connector Terminal C35 And Line Pressure Switch Connector Terminal
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES - Replace the PCM (see ECM/PCM REPLACEMENT ).
NO - Repair an open in the wire between the line pressure switch connector terminal and PCM connector terminal C35.