B1850 01, B1850 06, B1860 01 or B1860 06
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the harness connector at the appropriate lumbar position sensor.
- Test for less than 2 ohms between the appropriate low reference circuit listed below and ground.
- Lumbar horizontal sensor terminal 3
- Lumbar vertical sensor terminal 1
- If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the MSM.
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit listed below and ground.
- Lumbar horizontal sensor terminal 1
- Lumbar vertical sensor terminal 3
- If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.
- If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the MSM.
- Verify the appropriate scan tool lumbar sensor parameter is less than 1 volt.
- If greater than the specified range, test the signal circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the MSM.
- Install a 3A fused jumper wire between the signal circuit terminal 2 and the appropriate 5-volt reference circuit listed below. Verify the appropriate scan tool lumbar sensor parameter is greater than 4.75 volts.
- Lumbar horizontal position sensor terminal 1
- Lumbar vertical position sensor terminal 3
- If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.
- If all circuits test normal, test or replace the lumbar position sensor.