Code Definition

P0890 — TCM Power Relay Sense Circuit Low

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About P0890

P0890 is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P0890 is stored, the module has detected a signal or supply voltage lower than the expected operating range.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P0890 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The fault code P0890 is set when the control module detects a low signal condition in the Transmission Control Module (TCM) power relay sense circuit. This low signal condition suggests that the voltage in the sense circuit, which is responsible for monitoring the status of the TCM power relay, is below the normal operational threshold. A low signal in this circuit can indicate problems in the relay's operation or in the circuit itself, potentially affecting the proper power supply to the TCM and impacting transmission performance.

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