P0745: Pressure Control Solenoid "A"

What does P0745 mean?

Common causes

• A connector or harness fault, checked first because it is outside the pan, not because the code has been shown to be electrical
• The gear-ratio fault ATSG 05-10 says must be fixed before the solenoid on a 5R55N or 5R55W/S with P0745 and P0733
• A pressure-control solenoid that fails the electrical test in a chart that actually defines P0745 as electrical
• Valve-body wear or a stuck pressure-regulator valve, when the chart's hydraulic branch is the one that failed
• Low line pressure from the pump or from internal leakage, measured with the gauge and the chart for this transmission
• The wrong part ordered because solenoid A was assumed to be the line-pressure solenoid

Symptoms

• Check engine light with P0745, with or without a gear-ratio code
• The shift this chart assigns to solenoid A delayed, harsh, or missing
• Harsh shifts in every range, on a unit whose solenoid A is the line-pressure solenoid and pressure is not being controlled
• A failsafe gear, which is the gear this calibration holds
• Burnt-smelling fluid, when the level check finds it
• A solenoid that tests in range and a ratio code that remains, which is the outcome ATSG 05-10 describes on the 5R55 units

Diagnostic steps

1. 1.Read the definition in this service manual before any part is ordered. If P0745 is paired with a gear-ratio code, follow that hydraulic procedure. On a 5R55N or 5R55W/S, ATSG 05-10 says to fix the third-gear ratio fault rather than replacing pressure control A and expecting the code to leave.
2. 2.Identify solenoid A in the application chart. Write down which clutch or which pressure it controls. On the Toyota transmissions cited under P0748, 'A' is shift solenoid SL1, not the line-pressure solenoid. The Ford 6F35 line-pressure solenoid is the part in that unit's P0748 pinpoint.
3. 3.Check fluid level and condition with this transmission's procedure. Temperature and engine speed change the reading. A unit with no dipstick is checked at the plug the procedure names.
4. 4.Ignition off. Inspect the case connector, then measure the solenoid against this chart's resistance specification. A passing reading does not end a performance diagnosis. ATSG 05-10 records solenoid replacement that left the code in place on the 5R55 units.
5. 5.If several gears are wrong, a shop measures line pressure with the gauge and the chart for this transmission. The 6F35 procedure uses gauge 307-004. Do not invent a psi limit, and do not follow a low reading with a stall-speed test.
6. 6.Open the pan only after the external circuit and the chart's next branch say to. Use a lift or stands. Let the fluid cool. Debris in the pan changes the decision from a solenoid to the valve body.
7. 7.Verify with a recorded drive: commanded gear or commanded pressure against the ratio. A passenger reads the tool. Confirm the ratio code, if there was one, is gone.

Repair cost

$300 – $900 (simple solenoid replacement)

Use this pair only when the diagnosed part is a simple solenoid. AutoZone's 'Bad Torque Converter vs Bad Transmission' prices that job at $300–$900 parts and labor. A 5R55 gear-ratio repair, a valve body, and a line-pressure pump are different jobs and were not given a national price here. AutoZone's rebuild band is $1,800–$3,500 and its replacement band is $4,000–$8,000. RepairPal's fluid-change average, updated 3 September 2026, is $294–$356, which is a service, not this code's repair. ATSG 05-10 says a solenoid replacement alone did not clear P0745 on the 5R55N and 5R55W/S.

DIY vs shop

Leave this one to a qualified shop. The barrier here is internal hydraulic and mechanical work, fluid handling at temperature, and an adaptive relearn afterwards without which a correct repair still shifts badly. DIY attempts often produce a more expensive problem than the original code.

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