Module Communications Network

1. Verify the customer concern by operating the system in question.
2. Visually inspect for obvious signs of electrical damage.

VISUAL INSPECTION CHART

Electrical
^ Battery junction box (BJB) Fuse 12(30A)
^ Wiring harness
^ Loose or Corroded connections
^ Anti-lock brake control module
^ Electronic automatic temperature control (EATC) module
^ Passive anti-theft system (PATS) nodule
^ Natural gas vehicle module (NGVM)
^ Electric crash sensor (ECS)
^ Driver door module (DDM)
^ Lighting control module (LCM)
^ Powertrain control module (PCM)

3. If the concern remains after the inspection, connect the scan tool to the DLC located beneath the instrument panel and select the vehicle to be tested from the scan tool menu. If the scan tool does not communicate with the vehicle:
^ Check that the program card is correctly installed.
^ Check that the correct version of the program card is installed.
^ Check the connections to the vehicle.
^ Check the ignition switch position.

If the scan tool still does not communicate with the vehicle, GO to Symptom Chart. Module Communications Network

4. GO to Pinpoint Test PC. Pinpoint Test PC (Precheck)