Circuit Description

1998 Oldsmobile Achieva 3.1 M, 4T40E/MN4SECTION Circuit Description

Output Driver Modules (ODM) are used by PCM to turn on current-driven devices needed to control various engine and transaxle functions. Each ODM can control up to 7 outputs, including fan 1 relay, by supplying ground to device PCM is commanding on. ODMs can diagnose each circuit individually. If ODM "B" output 1 (fan 1 relay driver circuit) detects an improper voltage level, P1651 is set.

Conditions required to set DTC are:

  • Ignition is on.
  • An improper voltage level detected on fan 1 relay driver circuit.
  • Condition present for at least 30 seconds.
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.