Low battery or system voltage from a weak battery or poor charging; Corroded, loose or damaged connectors or terminals on the PC solenoid supply circuit or at the transmission harness connector; Open or high resistance in the power feed wiring, or a blown or poorly seated fuse or relay supplying the circuit (layout varies by model); Poor battery cable or earth connections causing voltage drop; Faulty PC solenoid or internal transmission harness shorting or drawing excess current; Fault inside the transmission control module.

P1831

PC Solenoid Power Circuit Low Voltage.

GMC
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

P1831 on a GMC means the transmission control module has seen low voltage on the power supply feeding the pressure control (PC) solenoid circuit. The PC solenoid sets line pressure in the automatic transmission, so the module compares the supply voltage it sees with what it expects and sets the code when it falls too low. Exact circuit layout, fuse and relay arrangement depend on the model, engine and transmission fitted.

Symptoms

Harsh, delayed or flared gear changes
Transmission stuck in one gear or in limp mode
Warning light on, possibly with a transmission warning message
Slipping or no drive in some gears
Poor or inconsistent shift feel that varies with battery voltage

Possible causes

Low battery or system voltage from a weak battery or poor charginglikely
Corroded, loose or damaged connectors or terminals on the PC solenoid supply circuit or at the transmission harness connectorlikely
Open or high resistance in the power feed wiring, or a blown or poorly seated fuse or relay supplying the circuit (layout varies by model)possible
Poor battery cable or earth connections causing voltage droppossible
Faulty PC solenoid or internal transmission harness shorting or drawing excess currentpossible
Fault inside the transmission control modulerare

How to diagnose

Read all stored and pending codes and note the freeze frame data, including battery voltage at the time the code set
Check battery condition and state of charge, then test charging system output against the manufacturer's specification
Inspect battery terminals, main cables and earth points for corrosion, looseness or damage
Check the relevant fuses and relays for the transmission control circuit, using the wiring diagram for the specific model
Inspect the transmission harness connector and the control module connector for water ingress, bent or corroded pins and poor terminal tension
Measure voltage at the PC solenoid supply while the circuit is live, and voltage drop along the feed and earth, comparing with the wiring diagram
Check PC solenoid resistance against the specification for the transmission fitted, and inspect the internal harness for chafing
Clear the code and road test, watching live voltage and solenoid data to confirm the fault does not return

How to fix

Replace or recharge a weak battery and repair any charging system fault
Clean or repair corroded terminals, battery cables and earth connections
Repair or replace damaged wiring or connectors in the PC solenoid supply circuit
Replace the faulty fuse or relay after finding why it failed
Replace the PC solenoid or internal transmission harness if testing shows it is faulty
Replace or repair the transmission control module only after wiring, supply and solenoid have been proven good

Can I keep driving?

Medium severity

The car may still drive, but shifting can be harsh or the transmission may go into limp mode, and continued use with poor line pressure can cause clutch wear. Get it checked soon and avoid heavy loads or towing until fixed.

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