P093B

Code

Generic P — Powertrain

Hydraulic Accumulator Solenoid Circuit Low

Brand: Generic

Type: P — Powertrain

Views: UK: 17 EN: 30 RU: 29

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Page language: EN

Causes

Short to ground or low-voltage condition in the solenoid circuit
Open circuit or high resistance in wiring or connector
Corroded, bent, or loose connector pins
Failed hydraulic accumulator solenoid (coil open or shorted)
Blown fuse or weak battery/poor charging system
Poor ground at solenoid or control module

Symptoms

Malfunction indicator lamp (MIL) or transmission warning lamp illuminated
Transmission limp mode or reduced performance
Delayed, harsh, or inconsistent gear engagement
Stored diagnostic trouble codes related to hydraulic or transmission circuits
Possible loss of hydraulic pressure for functions controlled by the accumulator

What to check

Retrieve freeze frame and live data with a capable scan tool; note related codes and accumulator/pressure readings
Visually inspect solenoid connector and wiring for corrosion, damage, or water intrusion
Check for blown fuses and verify battery/charging system voltage
Backprobe the solenoid connector and measure voltage with key ON/engine OFF and while commanded ON by the scan tool
Measure solenoid coil resistance with an ohmmeter and compare to specification
Check continuity and resistance from solenoid connector to the PCM/TCM pin (verify no short to ground or VIN)

Signal parameters

Expected coil resistance (typical range): ~6–50 ohms — consult vehicle service data for exact value
Standby voltage at solenoid feed: battery voltage (~11–14.5 V) with key ON
Command signal: PWM duty cycle 0–100% or switched 0–12 V depending on design
Typical PWM frequency range: ~20–300 Hz (varies by manufacturer)
When commanded ON, voltage at solenoid should change according to specification (either pulled to ground or switched to voltage)
No continuity to ground (open circuit) or short to ground should be present at rest

Diagnostic algorithm

Confirm DTC: Connect a scan tool, read codes and freeze frame. Note related hydraulic or transmission codes.
Visual inspection: Inspect solenoid connector, wiring harness, and nearby components for damage, corrosion, or fluid contamination.
Power/ground check: With key ON, verify battery voltage at the solenoid power feed and verify solid ground at the solenoid ground terminal.
Measure coil resistance: Unplug solenoid and measure ohms across coil. Compare to service spec. Open or drastically low resistance indicates a faulty solenoid.
Command test: Backprobe the control pin and command the solenoid ON with the scan tool while monitoring voltage or duty cycle. Verify the control follows the command.
Circuit isolation: If control signal is present but solenoid does not actuate or coil resistance is out of range, replace the solenoid. If no control signal, check continuity from the control module to the solenoid and inspect for shorts to ground/Vb.
Check module output: If wiring is good and solenoid is good but no proper command is present, test the PCM/TCM output driver per manufacturer procedures or consider module fault after confirming wiring and components.
Re-test: Clear codes and perform road test/functional test to ensure the circuit operates correctly and the code does not return.
If intermittent: Perform wiggle tests, inspect for harness chafing, and monitor long-term data to capture intermittent faults.

Likely causes

Corroded or loose connector at the solenoid
Open or shorted wiring between the solenoid and control module
Failed solenoid coil (open or low resistance)
Poor ground connection for solenoid circuit

Fault status

⚠️ Status

Control module detected low voltage/low signal on the hydraulic accumulator solenoid circuit. The fault may trigger a transmission or powertrain warning and can cause reduced hydraulic control or limp mode. Further electrical and component testing is required.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0 - 3.0 hours