P0995
Transmission Fluid Pressure Sensor/Switch F Circuit High
Powertrain Transmission Control Pressure Sensor Circuit 🟡 Moderate — Fix within a week
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What This Actually Means
In plain language — no jargon

The transmission fluid pressure sensor is sending a signal that's too high, like a gauge needle stuck at maximum. The ECU thinks pressure is higher than physically possible, indicating a wiring or sensor problem.

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Symptoms You May Notice
3 known symptoms for this code
Check Engine Light (CEL) illuminated
Transmission shifting harshly or delayed shifts
Transmission may go into limp mode or safe mode
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Embedded Systems Insight
What the ECU/ECM is actually computing

The ECU monitors the voltage signal from the transmission fluid pressure sensor to verify actual hydraulic pressure. When the sensor voltage exceeds the maximum expected threshold (typically 4.8-5.0V), the ECU flags a high circuit fault. This usually indicates a short to power, corroded connector, or failed sensor.

Voltage & Parameter Thresholds

Parameter Normal Range Fault Condition
Sensor Voltage 0.5V - 4.5V (proportional to pressure) >4.8V (stuck high or shorted)
Pressure Range 10-400 PSI depending on gear Signal indicates impossible pressure value
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Diagnostic & DIY Fix Guide
Check these in order — from cheapest to most complex
1
Connector and wiring harness
Inspect the sensor connector for corrosion, loose pins, or moisture and clean or reseat connections.
2
Transmission Fluid Pressure Sensor
Replace the sensor if voltage remains high after cleaning connectors and checking wiring for shorts.
3
Transmission Control Module (TCM) wiring
Check the circuit wiring between sensor and TCM for pinched, damaged, or shorted wires.