The P0873: Transmission Fluid Pressure Sensor/Switch ‘C’ Circuit High fault code indicates that the transmission fluid pressure sensor or switch ‘C’ is detecting higher-than-expected voltage. This can result in transmission performance issues, improper shifting, or even potential damage to internal transmission components. The problem may be caused by a faulty sensor, wiring issues, or a malfunctioning transmission control module (TCM).
P0873 – Quick Overview
| Code | Information |
|---|---|
| Meaning | P0873: Transmission Fluid Pressure Sensor/Switch ‘C’ Circuit High |
| Is it serious? | Yes, it can cause improper transmission operation and lead to shifting problems. |
| Possible causes | – High voltage in the transmission fluid pressure sensor/switch ‘C’ circuit – Faulty sensor or wiring – Faulty transmission control module (TCM) |
| How to diagnose? | – Test the circuit for high voltage – Inspect wiring and connectors – Replace faulty components if needed |
P0873 Meaning
The P0873: Transmission Fluid Pressure Sensor/Switch ‘C’ Circuit High code indicates that the voltage in the transmission fluid pressure sensor/switch ‘C’ circuit is above the specified range. This high voltage can cause the transmission fluid pressure to be improperly monitored, which could lead to shifting issues or damage to the transmission.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to check for additional related codes that may provide further insight into the problem. | OBD-II Scanner |
| Test the Circuit for High Voltage | Use a multimeter to measure the voltage in the transmission fluid pressure sensor/switch ‘C’ circuit and compare it with manufacturer specifications. | Multimeter |
| Inspect the Sensor and Wiring | Visually inspect the transmission fluid pressure sensor and wiring for signs of damage, wear, corrosion, or loose connections. Replace or repair as necessary. | Flashlight, Multimeter |
| Test the Transmission Control Module (TCM) | Use a diagnostic tool to ensure that the TCM is functioning correctly and communicating properly with the sensor. | Diagnostic Tool |
| Replace Faulty Components | If the sensor, wiring, or TCM is found to be faulty, replace the necessary components to restore normal transmission fluid pressure operation. | Replacement Parts, Basic Tools |
| Clear the Code and Test Drive | After repairs, clear the code using an OBD-II scanner and take the vehicle for a test drive to ensure normal transmission operation. | OBD-II Scanner, Vehicle Owner’s Manual |
| Recheck for Codes | After the test drive, re-scan the system to confirm that the P0873 code does not return. | OBD-II Scanner |
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I test OBD-II scanners and make DIY Engine diagnostics guides to help you solve your car problems without having to depend on the mechanic. A lot of them will try to scam you or are just no help at all. About Juraj Lukacko