P0745

Code

Generic P — Powertrain

Pressure Control Solenoid A

Brand: Generic

Type: P — Powertrain

Views: UK: 38 EN: 46 RU: 57

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Page language: EN

Causes

Faulty pressure control solenoid A (stuck, shorted, open or intermittent)
Damaged wiring or poor connector connection (open, short to ground/voltage, corrosion)
Low or contaminated transmission fluid
Faulty transmission range sensor or transmission control module
Valve body or internal hydraulic failure (stuck valve, debris)
Intermittent ground or battery supply issue

Symptoms

Check Engine / Transmission warning light illuminated
Harsh, delayed, or erratic shifting
Transmission slipping or inability to hold gear
Limp-home mode (reduced shift schedule)
Unusual transmission noise or harsh engagement
Poor drivability, degraded fuel economy

What to check

Read freeze frame and live data with a scan tool; note transmission-related data and solenoid command/status
Visually inspect transmission fluid level and condition (burnt smell, debris)
Inspect wiring harness and connector for damage, corrosion, loose terminals, or water intrusion
Backprobe solenoid connector to check reference voltage, ground and control signal while commanding solenoid ON/OFF
Measure solenoid coil resistance with ohmmeter (compare to spec or similar solenoids)
Perform wiggle test on harness while monitoring live data to find intermittent faults

Signal parameters

Solenoid coil resistance: typically about 10–50 ohms (varies by manufacturer) — compare to OEM spec
Control method: PCM/TCM uses PWM (pulse-width modulation); typical frequency range 50–300 Hz (varies by design)
Command duty cycle: 0–100% depending on requested pressure
Supply amplitude: signal referenced to battery voltage; control is usually a pulsed ground or pulsed positive driven by module
Expected behavior: resistance within spec, control signal present when commanded, and measurable pressure change when activated

Diagnostic algorithm

Verify the code and note any other transmission codes. Scan for pending/frozen frame data and check for related codes.
Inspect transmission fluid level and condition. Top or replace fluid if low/contaminated; retest.
Visually inspect solenoid connector and wiring for damage, corrosion, pin push-out, or water intrusion. Repair as necessary.
With ignition ON (engine off), disconnect connector and measure solenoid coil resistance. Compare to spec. Replace solenoid if out of range or open/shorted.
Backprobe the connector with a scan tool while commanding the solenoid ON/OFF. Verify proper control signal (PWM) and reference voltage/ground. Check for intermittent signal while wiggling harness.
If control signal present but solenoid does not actuate, bench-test or replace solenoid. If no control signal, check fuse/relay and PCM/TCM output circuit for shorts/open or poor ground.
If wiring suspect, perform continuity and short-to-power/ground tests between PCM/TCM and solenoid connector. Repair any wiring faults.
If electrical and fluid are good, check valve body/pressure circuits (hydraulic test) for stuck valves or contamination; perform transmission pressure test with gauge to confirm regulation.
After repairs, clear codes, perform relearn procedures if required, and road test to confirm fix. Re-scan for recurrence.

Likely causes

Wiring harness chafed at frame or near connector
Corroded or bent solenoid connector pins
Solenoid coil internal failure (open or short)
Low fluid level or heavy contamination causing sticking
PCM/TCM driver output failure (less common)

Fault status

⚠️ Status

PCM detected a malfunction in the transmission pressure control solenoid A circuit or its operation. This may result in improper hydraulic pressure regulation and can trigger limp mode or degraded shift performance.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1-3 hours