Bus +/- Signals Open Or No Response From Power Liftgate Module
NOTE:
After making any repairs, perform BODY VERIFICATION TEST under VERIFICATION TESTS.
NOTE:
Ensure there is PCI Bus communication with other modules on the vehicle before proceeding. If not, refer to the symptom list and repair as necessary. See DIAGNOSTIC TROUBLE CODE IDENTIFICATION table.
- Verify communication with other modules. If scan tool does not communicate with other modules, go to appropriate symptom testing procedure. See DIAGNOSTIC TROUBLE CODE IDENTIFICATION table under SELF-DIAGNOSTIC SYSTEM. Turn ignition off. Disconnect Power Liftgate Module (PLGM) connectors. See POWER LIFTGATE MODULE under REMOVAL & INSTALLATION. Using DVOM, measure voltage between ground and PLGM connector C1 terminal No. 5 (Yellow/Red wire). See Fig 1. If voltage is greater than 10 volts, go to next step. If voltage is 10 volts or less, repair open in Yellow/Red wire between PLGM and fuse No. 32 located in Intelligent Power Module (IPM). See Figure.
- Using a test light connected to battery voltage, probe PLGM connector C1 terminal No. 8 (Black/White wire) or PLGM connector C2 terminal No. 20 (Black/Light Green wire). If test light illuminates at both terminals, go to next step. If test light does not illuminate at any terminal, repair open in Black/White or Black/Light Green wire between PLGM and splice S329 or S331 located in left rear of vehicle. See Fig 2.
- Obtain Scope Input Cable (CH7058), Cable To Probe Adapter (CH7062) and Red and Black test probes. Connect scope input cable to channel 1 connector on scan tool. Connect Red and Black test probes and probe adapter to scope input cable. Select PEP MODULE TOOLS on scan tool. Select LAB SCOPE then LIVE DATA. Select 12V SQUARE WAVE. Press F2 for scope then enter to select channel. Press F2 again and use down arrow to set voltage range to 20 volts. Set probe to x10. Press F2 again to complete. Connect Black probe to ground and Red probe to PLGM connector C2 terminal No. 11 (White/Violet wire). Turn ignition on. Monitor scope on scan tool. If voltage pulses between zero and 7.5 volts, go to next step. If voltage does not pulse between zero and 7.5 volts, repair open in White/Violet wire (PCI bus circuit) between PLGM and diagnostic junction port terminal No. 12. See Figure.
- Turn ignition on. Using DVOM, measure resistance between ground and PLGM connector C2 terminal No. 19 (Violet/Yellow wire). If resistance is 50 ohms or less, go to next step. If resistance is greater than 50 ohms, go to step 8.
- Turn the ignition off. Disconnect Body Control Module (BCM) connector C2. See COMPONENT LOCATIONS . See Figure. Turn the ignition on. Using DVOM, measure voltage between ground and PLGM connector C2 terminal No. 19 (Violet/Yellow wire). If no voltage is present, go to next step. If any voltage is present, repair short to voltage in Violet/Yellow wire.
- Using DVOM, measure resistance between ground and PLGM connector C2 terminal No. 19 (Violet/Yellow wire). If resistance is greater than 100 ohms, go to next step. If resistance is 100 ohms or less, repair short to ground in Violet/Yellow wire.
- Replace PLGM. See POWER LIFTGATE MODULE under REMOVAL & INSTALLATION.
- Using DVOM, measure resistance of Violet/Yellow wire between BCM connector C2 terminal No. 17 and PLGM connector C2 terminal No. 19. See Figure. If resistance is greater than 5 ohms, repair open in Violet/Yellow wire. If resistance is 5 ohms or less, replace BCM. See BODY CONTROL MODULE under REMOVAL & INSTALLATION.