Damaged or chafed wiring harness between the PCM and the transmission PC solenoid; Corroded or loose electrical connector at the transmission pass-through or solenoid body; Faulty PC solenoid with an internal short or open winding; Low transmission fluid level or contaminated fluid affecting solenoid operation; Failed transmission control module (TCM) or PCM driver circuit; Poor ground connection for the transmission or PCM

DTC codes / GM codes / P1831

P1831 · GMPC Solenoid Power Circuit Low Voltage

Q: What does code P1831 mean?

PC Solenoid Power Circuit Low Voltage. P1831 on a GM vehicle means the powertrain control module (PCM) has detected low voltage on the power circuit feeding the pressure control (PC) solenoid inside the automatic transmission. The PCM commands a current to the solenoid to regulate line pressure, and when the voltage on that circuit falls below the expected threshold, it sets this code and may default the transmission to a higher line pressure strategy.

P1831 on a GM vehicle means the powertrain control module (PCM) has detected low voltage on the power circuit feeding the pressure control (PC) solenoid inside the automatic transmission. The PCM commands a current to the solenoid to regulate line pressure, and when the voltage on that circuit falls below the expected threshold, it sets this code and may default the transmission to a higher line pressure strategy.

SystemPowertrain

Code typeGM specific

SeverityMedium

Fix difficultyIntermediate

AreaTransmission

Symptoms you may notice

Illuminated check engine light or transmission warning message on the dash
Harsh or delayed shifts, especially when the transmission is cold
Transmission may default to a fixed line pressure, causing firm engagements
Slipping or flaring during gear changes under load
Often no symptoms besides the warning light, particularly in early stages

Common causes, most likely first

Damaged or chafed wiring harness between the PCM and the transmission PC solenoid
Corroded or loose electrical connector at the transmission pass-through or solenoid body
Faulty PC solenoid with an internal short or open winding
Low transmission fluid level or contaminated fluid affecting solenoid operation
Failed transmission control module (TCM) or PCM driver circuit
Poor ground connection for the transmission or PCM

How to diagnose and fix it

Check transmission fluid level and condition; top off or service as needed
Inspect the transmission wiring harness and connectors for chafing, corrosion, or loose pins
Measure resistance of the PC solenoid at the transmission connector and compare to specification
Check voltage drop on the power circuit from the PCM to the solenoid while commanding the solenoid on
Verify ground integrity for the transmission and PCM
If wiring and solenoid test good, test the PCM driver circuit with a lab scope or substitute a known-good PCM
Replace the faulty PC solenoid or repair the wiring as needed, then clear codes and verify operation

PC Solenoid Circuit Checks Most Techs Skip

A low-voltage code on the PC solenoid circuit is often caused by a poor ground rather than a failed solenoid, so always load-test the ground circuit before condemning parts.
Transmission fluid that is low or contaminated with debris can cause the solenoid to draw excessive current, mimicking a circuit fault and setting P1831.
The PCM may set P1831 intermittently due to a wiring harness that rubs only during certain engine torque conditions, so wiggle-test the harness while monitoring live data.
Replacing the PC solenoid without checking the pass-through connector for corrosion often leads to a repeat failure within a few thousand miles.
This code does not always mean the solenoid is bad; a weak battery or charging system can cause low voltage on the circuit and trigger P1831 along with other low-voltage codes.

Can I keep driving with P1831?

You can usually drive the vehicle with P1831 set, but expect firmer shifts and possible transmission default to high line pressure. Avoid heavy towing or aggressive acceleration until the fault is repaired, and have it diagnosed soon to prevent transmission wear.

Tools that help

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Guidance is general and written for GM vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.