Circuit Description

1999 GMC Forward Control 5.7 R, AutomaticSECTION Circuit Description
WARNING: This page is about a different car, the 2002 Pontiac Grand Am, 2002 Oldsmobile Alero, 2002 Chevrolet Monte Carlo, and 2002 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.

The Ignition Control (IC) module has independent power and ground circuits. The circuits between the IC module and the Powertrain Control Module (PCM) consist of the following circuits:

  • The IC timing signal.
  • The IC timing control.
  • The low resolution engine speed signal.
  • A low reference signal.

The Ignition Control (IC) module sends 3x signals to the Powertrain Control Module (PCM). The IC module controls the timing advance during engine cranking. The timing advance changes to PCM control after the following actions:

  • The PCM receives the second 3x signal.
  • The PCM applies 5 volts to the IC timing signal circuit.
  • The timing advance switches to PCM control.

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.
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