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.
2. 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.
3. Disconnect the X2, X4 harness connectors at the HSM.
4. Test for 850 Ohms - 300 kOhms between the signal circuit terminal 10 X4 and the low reference circuit terminal 7 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.
5. Connect the X1, X2, X4 harness connectors at the HSM.
6. Disconnect the harness connector at the seat back heater element/temperature sensor.
7. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground.
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 HSM.
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
HSM.
8. If all circuits test normal, replace the HSM.
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 HSM replacement, setup, and programming
HP2 or Dealer Installed W/O Memory
DTC B1925 or B2170 (HP2 or Dealer Installed w/o Memory)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC B1925 02
- Left Seat Heater Cushion Sensor Circuit Shorted to Ground
DTC B1925 05
- Left Seat Heater Cushion Sensor Circuit Shorted to Battery or Open
DTC B2170 02
- Right Seat Heater Cushion Sensor Circuit Shorted to Ground
DTC B2170 05
- Right Seat Heater Cushion Sensor Circuit Shorted to Battery or Open
Diagnostic Fault Information
