P093A

Code

Generic P — Powertrain

Hydraulic Accumulator Solenoid Circuit/Open

Brand: Generic

Type: P — Powertrain

Views: UK: 29 EN: 72 RU: 33

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Page language: EN

Causes

Open or broken wiring in solenoid circuit
Corroded, damaged, or loose connector/pins at solenoid
Failed hydraulic accumulator solenoid coil
Faulty ground or power feed (blown fuse, bad relay)
Intermittent wiring fault caused by chafing or heat damage
Faulty transmission control module (TCM) or PCM driver stage

Symptoms

Check Engine / Transmission warning lamp illuminated
Transmission may enter limp/limitation mode or fail-safe
Harsh, delayed, or incomplete shifts
Unstable line pressure or erratic shift timing
Possible inability to engage gears or reduced drivability

What to check

Retrieve freeze frame and live PID data with scan tool; confirm P093A presence and related codes
Visually inspect solenoid connector and wiring for damage, corrosion, or pushed-out pins
Check related fuses and relays for power to transmission/accumulator circuits
Backprobe solenoid connector while commanding solenoid on/off with scan tool to verify activation signal and voltage
Measure solenoid coil resistance with multimeter (unplugged) and compare to specification
Perform continuity checks between solenoid connector pins and control module pins

Signal parameters

Typical coil resistance: approximately 5–40 ohms (varies by design) — compare to OEM spec
Command voltage when activated: PWM switching to near battery voltage (0–12 V) with duty cycle control; static power feed may be constant 12 V with ground switching depending on design
Current draw when activated: typically 0.5–2 A (depends on coil resistance and PWM)
Open-circuit symptom: infinite/very high resistance on coil measurement; Short symptom: near 0 ohms or excessive current draw
Intermittent fault: fluctuating signal or drop-out when harness is moved

Diagnostic algorithm

Record DTCs, freeze-frame data, and vehicle symptom history. Note related codes (TCM/voltage).
Visually inspect solenoid connector, wiring harness, and transmission area for damage, corrosion, or fluid intrusion. Repair obvious issues.
Check fuses/relays supplying solenoid power and restore as needed.
With ignition off, disconnect solenoid connector and measure coil resistance across solenoid terminals; compare to OEM spec. Replace solenoid if out-of-range.
Check continuity between solenoid connector and the TCM/PCM control connector; repair any open/shorts. Verify good chassis/transmission ground.
Reconnect and backprobe while commanding the solenoid ON with a scan tool. Verify expected PWM/voltage is present and that the solenoid responds. Use an oscilloscope for intermittent/PWM analysis if available.
If the control module is not commanding or output is out of spec but wiring and solenoid are good, test or replace the control module driver stage per manufacturer procedures.
After repairs, clear codes and perform a road or dyno test to confirm the fault does not return. Monitor live data for correct pressure/shift behavior.

Likely causes

Connector corrosion or bent pins at solenoid
Broken wire at harness flex point or near transmission mount
Solenoid coil open (high resistance) or internally shorted
Blown fuse or poor fused power supply to solenoid
Poor ground at transmission case or chassis ground strap

Fault status

⚠️ Status

Module reports Hydraulic Accumulator Solenoid Circuit/Open: control module detects an open or abnormal signal in the accumulator solenoid circuit when the solenoid is commanded.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.5 hours