Wiring short to ground or chafed insulation on the stator temperature switch circuit; Faulty stator temperature switch or its internal connection; Corroded, damaged or contaminated connector at the transmission or control module, including fluid wicking into the harness; Overheated transmission fluid or a genuine high converter temperature condition causing the switch to change state; Internal transmission harness or case connector fault; Faulty transmission control module.

P1873

TCC Stator Temp. Switch Circuit Low.

Buick
Powertrain
Manufacturer code
Medium severity

How this code is built

P: SystemPowertrain
1: Defined byThe manufacturer
8: AreaTransmission
73: FaultThe specific fault in that area

What it means

P1873 on a Buick means the transmission control module saw a low voltage signal from the torque converter clutch (TCC) stator temperature switch circuit. The switch is used to monitor converter temperature and help manage TCC operation. A low signal outside the expected range for the operating conditions sets the code. The exact circuit layout and switch location depend on the model and transmission.

Symptoms

Check engine light or transmission warning light on
Torque converter clutch not applying, or applying at odd times
Poorer fuel economy at cruising speeds
Transmission running hotter than normal
Harsh or inconsistent converter lock-up feel
Transmission may default to a limited operating strategy

Possible causes

Wiring short to ground or chafed insulation on the stator temperature switch circuitlikely
Faulty stator temperature switch or its internal connectionlikely
Corroded, damaged or contaminated connector at the transmission or control module, including fluid wicking into the harnesspossible
Overheated transmission fluid or a genuine high converter temperature condition causing the switch to change statepossible
Internal transmission harness or case connector faultpossible
Faulty transmission control modulerare

How to diagnose

Read all stored codes and freeze frame data, noting transmission temperature, speed and load when the code set
Check transmission fluid level and condition, looking for a burnt smell, dark colour or debris
Inspect the wiring and connectors between the transmission and control module for chafing, corrosion, fluid contamination and pushed-back pins
Check the circuit for a short to ground and for continuity against the manufacturer's wiring diagram
Test the stator temperature switch against the manufacturer's specification, as the expected switch state varies by model and transmission
Monitor live data for TCC command, slip and fluid temperature to see if the signal matches real conditions
Check the transmission for signs of overheating, such as a blocked or restricted cooler circuit
Check for technical service bulletins for your model and transmission before condemning the control module

How to fix

Repair or replace damaged wiring and fix any short to ground
Clean or replace corroded or damaged connectors and terminals
Replace the stator temperature switch or affected internal harness if it fails testing
Correct the fluid level or change the fluid and filter if it is degraded, and fix any cooler flow problem
Repair the cause of any genuine overheating before clearing the code
Replace or reprogram the control module only after all other causes are ruled out and as the manufacturer directs

Can I keep driving?

Medium severity

The car can usually be driven for a short time, but avoid heavy loads or towing and book it in soon. If the transmission is running hot or the converter is slipping, stop driving to avoid damage.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.