P094C

Code

Generic P — Powertrain

Hydraulic Pump Performance/Stuck Off

Brand: Generic

Type: P — Powertrain

Views: UK: 32 EN: 42 RU: 32

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Low or contaminated hydraulic/transmission fluid
Clogged suction/pickup or filter
Failed or mechanically seized hydraulic pump
Control valve or solenoid stuck in the off position
Wiring harness connector fault or open/short to pump/solenoid
Faulty pressure sensor or incorrect pressure reading

Symptoms

MIL (Check Engine/Transmission) or lamp illuminated
Transmission slipping, delayed or no gear engagement
Transmission limp-home mode or reduced functionality
Unusual whining/growling from hydraulic pump area
Loss of hydraulic-assisted functions (if applicable)
Transmission fluid overheating, foaming, or unusual smell

What to check

Read and record all stored codes and freeze frame data from PCM/TCM
Check transmission/hydraulic fluid level and inspect fluid condition (metal, smell, color, contamination)
Visually inspect wiring and connectors to pump, pressure sensor, and solenoids for damage, corrosion, or loose pins
Listen for pump noise at key on/engine idle and during commanded operation
Scan live data: monitor pressure sensor reading, pump command and actual duty cycle, and related CAN/TCM messages
Check for service bulletins related to pump/calibration for the vehicle

Signal parameters

Hydraulic/transmission pressure (psi or bar) from pressure sensor
Pump supply voltage (battery voltage) and ground integrity
Pump command signal (duty cycle or on/off from TCM/PCM)
Solenoid control voltage/duty cycle for pressure control valves
Pump motor current draw (A) under operation
Engine RPM vs commanded pressure response

Diagnostic algorithm

Retrieve complete DTC list and freeze frame; note related transmission codes
Verify fluid level and condition; if low or severely contaminated, top-up or replace fluid and filter per service procedure
Inspect harness/connectors to pump, solenoid(s), and pressure sensor; repair any damaged wiring or poor connections
Check for pump mechanical noise at key-on and engine idle; note if pump runs and whether sound changes under load
Using a scan tool, command the pump/solenoid (if possible) and observe command vs actual pressure and solenoid response
Measure pump motor current while commanded; compare to spec to detect seizing or internal short/open
Install a manual hydraulic/transmission pressure gauge at the test port and measure line pressure at key test conditions (idle, commanded on, during shifts); compare to specs
If pressure is low but electrical commands present and current normal, inspect suction/pickup/filter for blockage; remove and clean/replace as required
If pump does not run electrically but has proper voltage/ground, replace pump assembly; if solenoid is stuck off, replace solenoid/valve body as required
Replace faulty pressure sensor if it reads out of range and wiring checks good
Clear codes and perform a controlled road test to confirm repair; re-scan for return or new codes

Likely causes

Low fluid level or severely contaminated fluid restricting pump flow
Clogged pickup or filter causing cavitation/low flow
Pump internal failure (bearing or vane wear) resulting in loss of pressure
Control solenoid/valve stuck open/off due to contamination or electrical fault
Open/short in pump/solenoid power or control wiring
Faulty pressure sensor sending incorrect low-pressure signal

Fault status

⚠️ Status

DTC P094C — Hydraulic Pump Performance / Stuck Off. Control module detected inadequate hydraulic pressure or pump not operating as commanded. MIL may be set and vehicle may be in limp mode until system pressure is restored.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1-4 hours