4. Test for 3.5 - 11.5 Ohms between control circuit terminal 14 and control circuit terminal 1.
锟斤拷 If less than the specified range, test for a short between the control circuits. If the circuits test normal, replace the seat back heater element.
锟斤拷 If greater than the specified range, test the control circuits for an open/high resistance. If the circuits test normal, replace the seat back
heater element.
5. Disconnect the X2, X5 harness connectors at the MSM.
6. Test for 850 Ohms - 300 kOhms between the signal circuit terminal 4 X5 and the low reference circuit terminal 2 X2.
锟斤拷 If less than the specified range, test for a short between the signal and low reference circuits. If the circuits test normal, replace the seat
back heater element/temperature sensor.
锟斤拷 If greater than the specified range, test the signal and low reference circuits for a short to voltage or an open/high resistance. If the circuits
test normal, replace the seat back heater element/temperature sensor.
7. Connect the X1, X2, X5 harness connectors at the MSM.
8. Disconnect the harness connector at the seat back heater element/temperature sensor.
9. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground.
锟斤拷 If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the
MSM.
锟斤拷 If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the MSM.
10. If all circuits test normal, replace the MSM.
B2180 0A, B2180 0B, B2180 0C, B2180 0D, B2180 0E, B2180 04, or B2180 1F
1. Ignition OFF, disconnect the X3 harness connector at the MSM.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 5 and ground.
锟斤拷 If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
3. Ignition OFF, connect the X3 harness connector at the MSM and disconnect the X1 harness connector at the MSM.
Important: Element resistance must be measured twice to ensure that all failure conditions are simulated. First with the seat
unoccupied, then with the seat occupied.
4. Test for 3.5 - 11.5 Ohms between control circuit terminal 6 and control circuit terminal 4.
锟斤拷 If less than the specified range, test for a short between the control circuits. If the circuits test normal, replace the seat back heater element.
锟斤拷 If greater than the specified range, test the control circuits for an open/high resistance. If the circuits test normal, replace the seat back
heater element.
5. Disconnect the X2, X5 harness connectors at the MSM.
6. Test for 850 Ohms - 300 kOhms between the signal circuit terminal 3 X5 and the low reference circuit terminal 5 X2.
锟斤拷 If less than the specified range, test for a short between the signal and low reference circuits. If the circuits test normal, replace the seat
back heater element/temperature sensor.
锟斤拷 If greater than the specified range, test the signal and low reference circuits for a short to voltage or an open/high resistance. If the circuits
test normal, replace the seat back heater element/temperature sensor.
7. Connect the X1, X2, X5 harness connectors at the MSM.
8. Disconnect the harness connector at the seat back heater element/temperature sensor.
9. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground.
锟斤拷 If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the
MSM.
锟斤拷 If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the MSM.
10. If all circuits test normal, replace the MSM.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Driver or Passenger Seat Back Cushion Heater Replacement (Escalade with HP2) ()Driver or Passenger Seat Back Cushion Heater
Replacement (Tahoe with HP2) ()Driver or Passenger Seat Back Cushion Heater Replacement (without HP2) ()
* Control Module References (See: Testing and Inspection/Programming and Relearning) for the MSM replacement, setup, and programming
