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Home >> Oldsmobile >> 2001 >> Bravada >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Anti-Theft Systems >> Anti-Theft System >> Diagnostic Tests >> DTC P1626: Powertrain Control Module To Body Control Module Communications Fault >> Diagnostic Procedure
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Diagnostic Procedure

  1. If anti-theft system diagnostic system check has been performed, go to next step. If anti-theft system diagnostic system check has been performed, perform ANTI-THEFT SYSTEM DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM.
  2. Install scan tool. Momentarily rotate ignition switch to CRANK position. DO NOT start engine. Release ignition switch to ON position. Select PCM display DTCs function. If scan tool displays DTC P1626 as a current DTC, go to next step. If scan tool does not display DTC P1626 as a current code, diagnose and repair intermittent problem.
  3. Check Class 2 Serial Data circuit for an open in Class 2 Serial Data circuit (Yellow wire) between PCM and BCM, a short to ground, a short to voltage, or loose or damaged terminals at Data Link Connector (DLC), PCM or BCM. If problem is found, go to step  6 . If problem is not found, go to next step.
  4. Turn ignition off. Connect or install any connectors or components that were disconnected or removed. Clear all DTCs using scan tool. Turn ignition off for 15 seconds. Attempt to start engine. If DTC P1626 resets, go to step  8 . If DTC P1626 does not reset, go to next step.
  5. This DTC is intermittent. If any additional DTCs are stored, see DIAGNOSTIC TROUBLE CODE INDEX  . If no other DTCs are stored, check for and repair intermittent problem.
  6. Repair circuit at necessary and then go to next step.
    7. NOTE: Before clearing DTCs, monitor all DTC status parameters and note any additional DTCs.
  7. Turn ignition off. Connect or install any connectors or components that were disconnected or removed. Clear all PCM DTCs using scan tool. Turn ignition off for 15 seconds. Start engine and allow it to run. If DTC resets, go back to step  2 . If DTC does not reset, system is okay.
  8. Inspect for poor connections at BCM. If problem was found, repair as necessary. If problem was not found, go to next step.
  9. Replace BCM. See BODY CONTROL MODULE  under REMOVAL & INSTALLATION.
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