Open circuit, high resistance or short to ground in the wiring feeding the PC solenoid power supply; Corroded, damaged or loose connector at the transmission harness or control module; Blown fuse or faulty relay in the transmission control power supply (location varies by model); Failed PC solenoid with internal short or low resistance, pulling the supply voltage down; Weak battery or charging system fault causing low system voltage; Internal fault in the transmission control module driver circuit.

P1831

PC Solenoid Power Circuit Low Voltage.

GM
Powertrain
Manufacturer code
Medium severity

How this code is built

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

What it means

On GM vehicles, P1831 means the transmission control module has detected low voltage on the supply feeding the pressure control (PC) solenoid. The PC solenoid sets line pressure in the automatic transmission, so the module watches its power feed. If the voltage is lower than expected, the module logs the code and may default to a fixed, high line pressure.

Symptoms

Harsh or slammed gear changes
Delayed or flared shifts
Transmission stuck in one gear (limp mode)
Gearbox warning light or check engine light on
Poor fuel economy or reduced performance
Intermittent shifting problems that come and go

Possible causes

Open circuit, high resistance or short to ground in the wiring feeding the PC solenoid power supplylikely
Corroded, damaged or loose connector at the transmission harness or control modulelikely
Blown fuse or faulty relay in the transmission control power supply (location varies by model)possible
Failed PC solenoid with internal short or low resistance, pulling the supply voltage downpossible
Weak battery or charging system fault causing low system voltagepossible
Internal fault in the transmission control module driver circuitrare

How to diagnose

Read all stored codes and freeze frame data, noting battery voltage and conditions when the code set, and check for other voltage or solenoid codes
Test battery condition and charging voltage, as low system voltage can set this code
Check the relevant fuses and relays for the transmission control supply, using the wiring diagram for the specific model
Inspect the transmission harness and connectors for chafing, corrosion, fluid contamination and bent or pushed-out pins
Wiggle-test the harness with live data or a voltage monitor running to catch intermittent faults
Measure supply voltage at the PC solenoid connector with the ignition on and compare with battery voltage
Measure PC solenoid resistance and compare with the manufacturer specification for that transmission
Check for continuity and shorts to ground on the supply wire between the module and the solenoid

How to fix

Repair or replace damaged wiring and correct any short or open circuit
Clean, repair or replace corroded or damaged connectors and terminals
Replace the blown fuse or faulty relay after finding out why it failed
Replace the PC solenoid if its resistance is out of specification or it is shorted
Repair the battery or charging system fault if system voltage is low
Replace or repair the transmission control module only after wiring and solenoid faults are ruled out

Can I keep driving?

Medium severity

The car can usually be driven short distances, but expect harsh shifts or limp mode, and high line pressure can accelerate transmission wear. Get it diagnosed soon and avoid heavy loads or towing until it is fixed.

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