Transmission Fluid Pressure Sensor/Switch A Circuit Intermittent
What does P0844 mean?
The P0844 code means the vehicle's onboard diagnostic system has detected: Transmission Fluid Pressure Sensor/Switch A Circuit Intermittent. This is a moderate severity code.
Common Symptoms
- Check Engine Light illuminated intermittently
- Occasional harsh shifts or flares
- Sporadic limp mode activation
- Transmission performance varies between drives
Probable Causes (Ranked by Likelihood)
- Loose connector at pressure sensor A Very High
- Intermittent wiring fault from vibration High
- Failing pressure sensor with intermittent output Moderate
- Intermittent internal transmission pressure fluctuation Low
Step-by-Step Diagnostic Procedure
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Perform a wiggle test on the sensor connector while monitoring live data
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Inspect wiring for chafing near the transmission bell housing
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Data-log pressure sensor readings over multiple drive cycles
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Check for TSBs related to intermittent pressure sensor faults
Frequently Asked Questions
Why does P0844 come and go?
Intermittent codes are caused by faults that only occur under certain conditions, such as vibration, temperature changes, or specific driving situations. The fault may not be present during a static inspection.
Should I replace the sensor if the code is intermittent?
Not immediately. Check the connector and wiring first. If those are in good condition and the code persists, then replace the sensor.
Can an intermittent pressure sensor cause transmission damage?
Over time, yes. Intermittent pressure readings can cause the TCM to make incorrect shift decisions, leading to clutch wear and overheating.