Circuit/System Testing

B1825, B2355, B2365, B2375

1. Ignition OFF, disconnect the X2 harness connector at the seat adjuster motor for which the DTC set.
2. Ignition OFF, test for less than 5 ohms of resistance between the appropriate low reference circuit terminal listed below and ground.
   • Seat horizontal motor sensor terminal C
   • Seat front vertical motor sensor terminal C
   • Seat rear vertical motor sensor terminal A
   • Seat recline motor sensor terminal 1
   • If greater than 5 ohms, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the MSM.
3. Ignition ON, test for 4.8-5.2 volts between the appropriate 5-volt reference circuit terminal listed below and ground.
   • Seat horizontal motor sensor terminal A
   • Seat front vertical motor sensor terminal A
   • Seat rear vertical motor sensor terminal C
   • Seat recline motor sensor terminal 3
   • If less than 4.8 volts, 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 5.2 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the MSM.
4. Verify the appropriate scan tool Driver Seat Sensor parameter is less than 2 volts.
   • If greater than 2 volts, test the appropriate signal circuit listed below for a short to voltage. If the circuit tests normal, replace the MSM.
     • Seat horizontal position sensor terminal B
     • Seat front vertical position sensor terminal B
     • Seat rear vertical position sensor terminal B
     • Seat recline motor sensor terminal 2
5. Install a 3A fused jumper wire between the appropriate signal circuit terminal and the 5-volt reference circuit terminal listed below. Verify the related scan tool Driver Seat position sensor parameter is greater than 4.75 volts.
   • Seat horizontal position sensor terminal A and terminal B
   • Seat front vertical position sensor terminal A and terminal B
   • Seat rear vertical position sensor terminal B and terminal C
   • Seat recline motor sensor terminal 2 and terminal 3
   • If less than 4.75 volts, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.
6. If all circuits test normal, test or replace the seat adjuster motor.

B1850

1. Ignition OFF, disconnect the X1 harness connector at the lumbar horizontal motor.
2. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal C and ground.
   • If greater than 5 ohms, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the MSM.
3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal D and ground.
   • If less than 4.8 volts, 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 5.2 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the MSM.
4. Verify the scan tool Lumbar Sensor parameter is less than 2 volts.
   • If greater than 2 volts, test the signal circuit for a short to voltage. If the circuit tests normal, replace the MSM.
5. Install a 3A fused jumper wire between the signal circuit terminal E and the 5-volt reference circuit terminal D. Verify the scan tool Lumbar Sensor parameter is greater than 4.75 volts.
   • If less than 4.75 volts, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the MSM.
6. If all circuits test normal, test or replace the lumbar motor assembly.