P1231 Buick Injector Circuit Cylinder 4 Intermittent

P1232 Buick Fuel Pump Speed Primary Circuit Malfunction

Possible causes
  • Open or shorted low fuel pump (LFP) circuit.
  • Open VPWR to the low speed fuel pump relay.
  • Damaged low speed fuel pump relay.
  • Damaged PCM.

    • Symptoms
    – Engine Light ON (or Service Engine Soon Warning Light)
    P1232 Buick Description

    The PCM monitors the low speed fuel pump (LFP) primary circuit output from the PCM. The test fails if: the LFP circuit is commanded ON (grounded), and excessive current draw is detected on the LFP circuit; or, the LFP circuit is commanded OFF, and voltage is not detected on the LFP circuit. The PCM expects to detect VPWR voltage through the low speed fuel pump relay coil to the LFP circuit.

    Buick Vehicle:Buick Regal – ?Buick Riviera – ?Buick LaCrosse – ?David Dunbar Buick – Buick Century – Buick LaCrosse – Buick LeSabre – Buick Lucerne – Buick Park Avenue – Buick Regal – Buick Verano – Buick Enclave – Buick Encore – Buick Rainier – Buick Rendezvous – Buick Terraza – Buick Riviera