Damaged, chafed or corroded wiring in the PC solenoid power supply circuit; Poor connection at the transmission harness connector or internal gearbox connector, including corrosion or loose terminals; Blown fuse or faulty relay or ignition feed supplying the transmission control circuit; Low system voltage from a weak battery, poor earth or charging fault; Faulty PC solenoid or internal transmission wiring causing excess current draw and voltage drop; Fault inside the transmission control module.

P1831

PC Solenoid Power Circuit Low Voltage.

Oldsmobile
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 an Oldsmobile means the transmission control module has seen low voltage on the supply feeding the pressure control (PC) solenoid circuit. The PC solenoid sets line pressure in the automatic gearbox, so the module compares the supply voltage it expects with what it measures and sets the code when it falls too low. The exact circuit layout and supply source depend on the model and transmission fitted.

Symptoms

Harsh or flared gear changes
Transmission stuck in one gear or in a limp-home mode
Gearbox warning light or check engine light on
Delayed or slipping engagement of drive or reverse
Changes in shift feel that come and go with electrical load

Possible causes

Damaged, chafed or corroded wiring in the PC solenoid power supply circuitlikely
Poor connection at the transmission harness connector or internal gearbox connector, including corrosion or loose terminalslikely
Blown fuse or faulty relay or ignition feed supplying the transmission control circuitpossible
Low system voltage from a weak battery, poor earth or charging faultpossible
Faulty PC solenoid or internal transmission wiring causing excess current draw and voltage droppossible
Fault inside the transmission control modulerare

How to diagnose

Read all stored codes and freeze frame data, noting battery voltage, gear and whether the fault is current or history.
Check battery condition and charging voltage, and inspect battery terminals and main earth connections.
Inspect the fuses and relays supplying the transmission control circuit, using the wiring diagram for the specific model.
Visually inspect the transmission harness and connectors for chafing, heat damage, fluid contamination, corrosion and pushed-back terminals.
With the connector disconnected, check the PC solenoid supply for correct voltage and for voltage drop under load while wiggling the harness.
Measure the PC solenoid resistance and compare it with the specification for that transmission.
Check the circuit for shorts to earth or high resistance between the control module and the solenoid.
Only if everything else tests good, verify module power and earth supplies before suspecting the module.

How to fix

Repair or replace damaged wiring and terminals in the PC solenoid supply circuit.
Clean, reseat or replace the corroded or loose transmission connectors.
Replace the blown fuse after finding what caused it, or replace a faulty relay.
Restore correct system voltage by repairing the battery, earth or charging fault.
Replace the PC solenoid or internal harness if it tests out of specification or is drawing excess current.
Replace or repair the transmission control module only after confirming the fault is in the module.

Can I keep driving?

Medium severity

The car can usually be driven for a short time, but harsh shifts or limp mode can stress the gearbox, so get it checked soon. Avoid heavy loads or towing until the fault is fixed.

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