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P1852

Brake Band Apply Solenoid Low Voltage.

  • GMC
  • Powertrain
  • Manufacturer code
  • Medium severity

How this code is built

P
SystemPowertrain
1
Defined byThe manufacturer
8
AreaTransmission
52
FaultThe specific fault in that area

What it means

P1852 on a GMC means the transmission control module saw a low voltage or open/short-to-ground condition on the brake band apply solenoid circuit. The module commands the solenoid and monitors the circuit, and the voltage did not match what it expected. This is a GM-specific definition and it mainly applies to older automatic transmissions that use a band; the exact layout depends on the model and transmission.

Symptoms

  • Warning light on, such as the check engine light or a transmission warning
  • Harsh, delayed or missing gear changes
  • Transmission stuck in one gear (limp mode)
  • Slipping or flare between certain gears
  • Poor fuel economy or reduced performance
  • Fault may come and go with temperature or vibration

Possible causes

  • Damaged, chafed or corroded wiring between the transmission connector and control module (open circuit or short to ground)likely
  • Poor connection or corrosion at the transmission internal harness connector or control module pluglikely
  • Faulty brake band apply solenoid with a failed or shorted coillikely
  • Contaminated or degraded transmission fluid affecting the solenoid or internal harnesspossible
  • Low or unstable system voltage from a weak battery or poor earthpossible
  • Faulty transmission control module driver circuitrare

How to diagnose

  1. Read all stored codes and freeze frame data, noting any other transmission or voltage codes, then clear and see if P1852 returns
  2. Check battery condition and charging voltage, and inspect main earth connections
  3. Check transmission fluid level and condition, looking for burnt smell, debris or contamination
  4. Visually inspect the external transmission harness and connector for chafing, heat damage, water ingress and corrosion
  5. Wiggle test the harness and connector with live data or a monitor to see if the fault appears
  6. Using the manufacturer wiring diagram for the specific model and transmission, test the solenoid circuit for continuity, short to ground and supply voltage
  7. Measure the solenoid coil resistance and compare with the specification for that transmission
  8. Check for any relevant technical bulletins or control module software updates for the vehicle

How to fix

  • Repair or replace damaged wiring and terminals in the solenoid circuit
  • Clean or replace the corroded or loose connector at the transmission or control module
  • Replace the faulty brake band apply solenoid or the solenoid assembly, as the transmission design requires
  • Change contaminated transmission fluid and filter, and repair the source of the contamination
  • Repair the charging system, battery or earths 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 carefully for a short time, but the transmission may go into limp mode and shift harshly. Have it checked soon, as continued slipping or harsh shifting can damage the transmission.

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

This code for other makes

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