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Test 13C - No Bus Bias

NOTE: For connector terminal identification, see CONNECTOR IDENTIFICATION  . For appropriate wiring diagram, see WIRING DIAGRAMS  at end of article.
CAUTION: Always turn ignition switch to OFF position prior to disconnecting or connecting any module connector.
  1. Ignition off during bus test is the most common cause for these messages. Turn ignition on, engine off. Disconnect DRB-II. Using an external voltmeter, check voltage between CCD data link connector CCD bus positive circuit (Violet/Brown wire) and ground. If voltage is not 2.3-2.6 volts, go to step 4).
  2. If voltage is 2.3-2.6 volts, check voltage between CCD data link connector CCD bus negative circuit (White/Black wire) and ground.
  3. If voltage is not 2.3-2.6 volts, go to next step. If voltage is 2.3-2.6 volts, replace DRB-II cable or cartridge as necessary. Perform VERIFICATION PROCEDURE VER-1.
  4. Disconnect Body Control Module (BCM). BCM is located behind right kick panel. Using an external ohmmeter, check resistance between BCM pins No. 14 and 15. See Figure . If resistance is not 100-140 ohms, replace BCM. Perform VERIFICATION PROCEDURE VER-1.
  5. If resistance is 100-140 ohms, check resistance between BCM Black connector terminal No. 7 and CCD data link connector CCD bus positive circuit (Violet/Brown wire). If resistance is more than 5 ohms, repair open circuit in Violet/Brown wire. Perform VERIFICATION PROCEDURE VER-1.
  6. If resistance is less than 5 ohms, check resistance between BCM Black connector terminal No. 20 and CCD data link connector CCD bus negative circuit (White/Black wire). If resistance is more than 5 ohms, repair open circuit in White/Black wire. Perform VERIFICATION PROCEDURE VER-1.
  7. If resistance is less than 5 ohms, reconnect DRB-II and place in voltmeter mode. Check voltage on BCM Black connector terminal No. 8, fused battery feed circuit (Pink/Light Blue wire). If voltage is not more than 10 volts, repair Pink/Light Blue wire as necessary. Perform VERIFICATION PROCEDURE VER-1.
  8. If voltage is more than 10 volts, check voltage on BCM Black connector terminal No. 6, fused ignition feed run/start circuit (Dark Blue/White wire). If voltage is not more than 10 volts, repair Dark Blue/White wire as necessary. Perform VERIFICATION PROCEDURE VER-1.
  9. If voltage is more than 10 volts, change DRB-II to ohmmeter mode. Check resistance of BCM Black connector terminal No. 19, ground circuit (Black/Light Green wire). If resistance is more than 15 ohms, repair open to ground in Black/Light Green wire. Perform VERIFICATION PROCEDURE VER-1.
  10. If resistance is less than 15 ohms, check resistance of BCM case ground. If resistance is more than 5 ohms, repair BCM case ground as necessary. Perform VERIFICATION PROCEDURE VER-1. If resistance is less than 5 ohms, replace BCM. Perform VERIFICATION PROCEDURE VER-1.
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