Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2000 Cadillac DeVille BaseFACTORY OEM SERVICE PROCEDURE
Lumbar Support Inoperative
NOTE:
This procedure applies to vehicles equipped with memory systems (A45). For option code definition, see REGULAR PRODUCTION OPTION CODES
under DESCRIPTION.
- If power seats diagnostic system check was performed, go to next step. If power seats diagnostic system check was not performed, go to POWER SEATS DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC TESTS.
- Using DVOM connected to ground, backprobe and measure voltage at driver's lumbar switch connector terminal "G" (Orange wire). See Fig 1 . If voltage is 9-16 volts, go to next step. If voltage is not 9-16 volts, go to step 6 .
- If lumbar moves when memory recall function is performed, go to next step. If lumbar does not move when memory recall function is performed, go to step 5 .
- Check for poor connections at driver's lumbar switch connector. If connections are okay, go to step 7 . If faulty connections are found and repaired, go to step 9 .
- Check for poor connections at Memory Seat Module (MSM) connector. See Figure . If connections are okay, go to step 8 . If faulty connections are found and repaired, go to step 9 .
- Repair open in Orange wire between lumbar switch and rear fuse block located under rear seat cushion. See Figure . After repairs, go to step 9 .
- Replace driver's lumbar switch. See DRIVER'S POWER SEAT SWITCH under REMOVAL & INSTALLATION. After repairs, go to step 9 .
- Replace MSM. See MEMORY SEAT MODULE under REMOVAL & INSTALLATION. After repairs, go to next step.
- Recheck power lumbar operation. If power lumbar malfunction is still present, go to step 2 . If power lumbar malfunction is no longer present, repair is complete.
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.