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GTECH Calibration
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P1562

Cruise Vacuum Solenoid.

  • Buick
  • Powertrain
  • Manufacturer code
  • Low severity

How this code is built

P
SystemPowertrain
1
Defined byThe manufacturer
5
AreaVehicle speed, idle control and auxiliary inputs
62
FaultThe specific fault in that area

What it means

On Buick models, P1562 relates to the cruise vacuum solenoid circuit. The control unit has detected a fault in this circuit, such as an open circuit, a short or a signal that does not match what it commanded. The exact set conditions and test thresholds vary by model and year, so check the manufacturer's data for the specific vehicle.

Symptoms

  • Cruise control will not engage or drops out unexpectedly
  • Cruise control surges or fails to hold speed
  • Cruise control warning or service light on, where fitted
  • Engine management light on
  • Cruise control works intermittently

Possible causes

  • Faulty cruise vacuum solenoid (vent or vacuum control valve)likely
  • Damaged, chafed or corroded wiring to the solenoidlikely
  • Loose, corroded or damaged connector at the solenoid or control modulelikely
  • Split, disconnected or leaking vacuum hose or cruise servopossible
  • Brake or clutch switch fault affecting the cruise circuit, or a blown fusepossible
  • Fault within the control module driver circuitrare

How to diagnose

  1. Read all stored and pending codes and note the freeze frame data, then check for other cruise or brake switch codes
  2. Check the fuse supplying the cruise circuit against the wiring diagram for the model
  3. Inspect the solenoid, its connector and the wiring for chafing, corrosion, heat damage and pushed-back pins
  4. Inspect the vacuum hoses and the servo or actuator for splits, loose fittings and leaks
  5. Test the solenoid coil resistance and compare it with the manufacturer's specification
  6. Check for supply voltage and ground at the solenoid connector with the ignition on, following the wiring diagram
  7. Check the brake and clutch switch operation, as they can interrupt the cruise circuit
  8. Back-probe the control signal to confirm the module is switching the solenoid, and test the circuit for continuity and shorts

How to fix

  • Replace the cruise vacuum solenoid if it fails its resistance or operation test
  • Repair or replace damaged wiring and fix any short or open circuit
  • Clean, repair or replace the faulty connector or terminals
  • Replace perished, split or leaking vacuum hoses or a faulty servo
  • Replace a faulty brake or clutch switch or a blown fuse after finding why it failed
  • Repair or replace the control module only after all wiring and component faults have been ruled out

Can I keep driving?

Low severity

The car is normally safe to drive, but cruise control may not work. Book it in for repair at your convenience.

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

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