Seat Heating System & Seat Cooling System Cadillac Escalade GMT900

Fastener Tightening Specifications

Scheme 100

Scheme 101

Scheme 102

Scheme 103

Scheme 104

Scheme 105

Scheme 106

Scheme 107

Scheme 108

Scheme 109

Scheme 110

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit/System Description

The heated seat temperature sensor that set this diagnostic trouble code (DTC) is located in the seat cushion just under the seat cover with the seat heating element. The temperature sensor is a 2 wire thermistor and resistance through the sensor varies with temperature. The signal circuit is referenced from 5 V within the memory seat module (MSM) and the temperature of the seat surface determines the signal circuit voltage. Once the seat reaches the set temperature, the MSM will then cycle the control circuits of the heating elements ON and OFF in order to maintain the desired seat temperature based on the feedback voltage from the sensors.

Conditions for Running the DTC

The MSM must be powered.

B1925 02 or B2170 02

The temperature sensor voltage drops below 0.80 V for more than 1 second.

B1925 05 or B2170 05

The temperature sensor voltage is greater than 5 Vs for more than 1 second.

Action Taken When the DTC Sets

The heated seat function for the affected seat will be disabled.

Conditions for Clearing the DTC

1. The current DTC will clear 3 seconds after the reference voltage returns to normal operating range, and the ignition is cycled OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Reference Information

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Verify the type of vehicle and the heated seat system for which the DTC set.

1. If the DTC set in a vehicle equipped with memory, refer to Circuit/System Testing below.
2. If the DTC set in a hybrid or a non-hybrid vehicle without memory, refer to DTC B1925 or B2170 (HP2 or dealer installed w/o memory).
3. If the DTC set in the rear heated seat module, refer to DTC B1925 or B2170 (Rear seat).

Circuit/System Testing

B1925 02 or B1925 05

1. Ignition OFF, disconnect the X2, X5 harness connectors at the MSM.
2. Test for 850 ohms - 300 kohms between the signal circuit terminal 1 X5 and the low reference circuit terminal 3 X2. 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 cushion heater element/temperature sensor. 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 cushion heater element/temperature sensor.
3. Connect the X2, X5 harness connectors at the MSM.
4. Disconnect the harness connector at the seat cushion heater element/temperature sensor.
5. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground. 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. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the MSM.
6. If all circuits test normal, replace the MSM.

B2170 02 or B2170 05

1. Ignition OFF, disconnect the X2, X5 harness connectors at the MSM.
2. Test for 850 ohms - 300 kohms between the signal circuit terminal 2 X5 and the low reference circuit terminal 6 X2. 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 cushion heater element/temperature sensor. 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 cushion heater element/temperature sensor.
3. Connect the X2, X5 harness connectors at the MSM.
4. Disconnect the harness connector at the seat cushion heater element/temperature sensor.
5. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground. 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. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the MSM.
6. If all circuits test normal, replace the MSM.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver or Passenger Seat Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Cushion Heater Replacement (with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
2. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the MSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The heated seat temperature sensor that set this diagnostic trouble code (DTC) is located in the seat cushion just under the seat cover with the seat heating element. The heated seat module (HSM) supplies a 5 V reference voltage through the temperature sensor signal circuit and a ground through the low reference circuit to the sensor. The module monitors the voltage of the sensor signal circuit to determine the temperature of the seat. The temperature sensor varies in resistance based on the temperature of the heating element causing the signal voltage to change. Once the seat reaches the set temperature, the module will then cycle the control circuit of the heating elements ON and OFF in order to maintain the desired seat temperature based on the feedback voltage from the sensor.

The HSM must be powered.

The temperature sensor voltage drops below 0.80 V for more than 1 second.

The temperature sensor voltage is greater than 5 V for more than 1 second.

The heated seat function for the affected seat will be disabled.

1. The current DTC will clear 3 seconds after the reference voltage returns to normal operating range, and the ignition is cycled OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Verify the type of vehicle and the heated seat system for which the DTC set.

1. If the DTC set in a hybrid or a non-hybrid vehicle without memory, refer to Circuit/System Testing below.
2. If the DTC set in a vehicle equipped with memory, refer to DTC B1925 or B2170 (w/o HP2 with memory).
3. If the DTC set in the rear heated seat module, refer to DTC B1925 or B2170 (Rear seat).

B1925 02, B1925 05

1. Ignition OFF, disconnect the X2, X4 harness connectors at the HSM.
2. Test for 850 ohms - 300 kohms between the signal circuit terminal 9 X4 and the low reference circuit terminal 6 X2. 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 cushion heater element/temperature sensor. 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 cushion heater element/temperature sensor.
3. Connect the X2, X4 harness connectors at the HSM.
4. Disconnect the harness connector at the seat cushion heater element/temperature sensor.
5. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground. 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. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HSM.
6. If all circuits test normal, replace the HSM.

B2170 02 or B2170 05

1. Ignition OFF, disconnect the X2, X4 harness connectors at the HSM.
2. Test for 850 ohms - 300 kohms between the signal circuit terminal 20 X4 and the low reference circuit terminal 8 X2. 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 cushion heater element/temperature sensor. 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 cushion heater element/temperature sensor.
3. Connect the X2, X4 harness connectors at the HSM.
4. Disconnect the harness connector at the seat cushion heater element/temperature sensor.
5. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground. 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. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HSM.
6. If all circuits test normal, replace the HSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver or Passenger Seat Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Cushion Heater Replacement (with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
2. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the HSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The heated seat temperature sensor that set this diagnostic trouble code (DTC) is located in the seat cushion just under the seat cover with the seat heating element. The rear heated seat module (RHSM) supplies a 5 V reference voltage through the temperature sensor signal circuit and a ground through the low reference circuit to the sensor. The RHSM monitors the voltage of the sensor signal circuit to determine the temperature of the seat. The temperature sensor varies in resistance based on the temperature of the heating element causing the signal voltage to change. Once the seat reaches the set temperature, the RHSM will then cycle the control circuit of the heating elements ON and OFF in order to maintain the desired seat temperature based on the feedback voltage from the sensor.

The RHSM must be powered.

The temperature sensor voltage drops below 0.80 V for more than 1 second.

The temperature sensor voltage is greater than 5 V for more than 1 second.

The heated seat function for the affected seat will be disabled.

1. The current DTC will clear 3 seconds after the reference voltage returns to normal operating range, and the ignition is cycled OFF then back to ACC or RUN.
2. A history DTC will clear after 50 ignition cycles or with a scan tool using the clear DTCs function.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Verify the type of vehicle and the heated seat system for which the DTC set.

1. If the DTC set in the rear heated seat module, refer to Circuit/System Testing below.
2. If the DTC set in a vehicle equipped with memory, refer to DTC B1925 or B2170 (w/o HP2 with memory).
3. If the DTC set in a hybrid or a non-hybrid vehicle without memory, refer to DTC B1925 or B2170 (HP2 or dealer installed w/o memory).

B1925 02, B1925 05

1. Ignition OFF, disconnect the X2, X4 harness connectors at the RHSM.
2. Test for 850 ohms - 300 kohms between the signal circuit terminal 9 X4 and the low reference circuit terminal 6 X2. 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 cushion heater element/temperature sensor. 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 cushion heater element/temperature sensor.
3. Connect the X2, X4 harness connectors at the RHSM.
4. Disconnect the harness connector at the seat cushion heater element/temperature sensor.
5. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground. 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 RHSM. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the RHSM.
6. If all circuits test normal, replace the RHSM.

B2170 02 or B2170 05

1. Ignition OFF, disconnect the X2, X4 harness connectors at the RHSM.
2. Test for 850 ohms - 300 kohms between the signal circuit terminal 20 X4 and the low reference circuit terminal 8 X2. 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 cushion heater element/temperature sensor. 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 cushion heater element/temperature sensor.
3. Connect the X2, X4 harness connectors at the RHSM.
4. Disconnect the harness connector at the seat cushion heater element/temperature sensor.
5. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground. 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 RHSM. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the RHSM.
6. If all circuits test normal, replace the RHSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Rear Seat Cushion Heater Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
2. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the RHSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When the heated seat function is active, the memory seat module (MSM) supplies battery voltage through the element supply voltage circuit to the seat heater elements. The module controls the seat temperature by providing a PWM ground through the heated seat element control circuit to the seat heater elements. The module then monitors the current flow through the heating element and the temperature sensor rate of change to verify correct operation.

The MSM must be powered and the heated seat must be enabled.

B1935 04 or B2180 04

The module does not detect a temperature change within 210 seconds.

B1935 0A or B2180 0A

The module detects that the set point temperature has not been reached within 8.5 minutes.

B1935 0B, B1935 0E, B2180 0B, or B2180 0E

By measuring output current, the module calculates that the heating element resistance is below the minimum resistance.

B1935 0C, B1935 0D, B2180 0C, or B2180 0D

By measuring output current, the module calculates that the heating element resistance is above the maximum resistance.

B1935 1F or B2180 1F

The temperature sensor voltage is erratic or changes suddenly.

The heated seat back function for the affected seat will be disabled.

1. The current DTC clears when the malfunction is no longer present and the power mode changes to OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Verify the type of vehicle and the heated seat system for which the DTC set.

1. If the DTC set in a vehicle equipped with memory, refer to Circuit/System Testing below.
2. If the DTC set in a hybrid vehicle without memory, refer to DTC B1935 or B2180 (HP2 w/o memory).
3. If the DTC set in a non-hybrid vehicle without memory, refer to DTC B1935 or B2180 (Dealer installed).

B1935 0A, B1935 0B, B1935 0C, B1935 0D, B1935 0E, B1935 04, or B1935 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. 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.
4. Test for 3.5 - 11.5 ohms between control circuit terminal 14 and control circuit terminal 1. 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. 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. 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. 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. 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. 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. 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.
4. Test for 3.5 - 11.5 ohms between control circuit terminal 6 and control circuit terminal 4. 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. 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. 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. 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. 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. 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.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver or Passenger Seat Back Cushion Heater Replacement (Escalade with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (Tahoe with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system__driver-or-passenger-seat-back-cushion)
2. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the MSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When the heated seat function is active, the heated seat module (HSM) supplies battery voltage through the element supply voltage circuit to the seat heater elements. The module controls the seat temperature by providing a PWM ground through the heated seat element control circuit to the seat heater elements. The module then monitors the current flow through the heating element and the temperature sensor rate of change to verify correct operation.

The HSM must be powered and the heated seat must be enabled.

The module does not detect a temperature change within 210 seconds.

The module detects that the set point temperature has not been reached within 8.5 minutes.

By measuring output current, the module calculates that the heating element resistance is below the minimum resistance.

By measuring output current, the module calculates that the heating element resistance is above the maximum resistance.

The temperature sensor voltage is erratic or changes suddenly.

The heated seat back function for the affected seat will be disabled.

1. The current DTC clears when the malfunction is no longer present and the power mode changes to OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Verify the type of vehicle and the heated seat system for which the DTC set.

1. If the DTC set in a hybrid vehicle without memory, refer to Circuit/System Testing below.
2. If the DTC set in a vehicle equipped with memory, refer to DTC B1935 or B2180 (w/o HP2 with memory).
3. If the DTC set in a non-hybrid vehicle without memory, refer to DTC B1935 or B2180 (Dealer installed).

B1935 0A, B1935 0B, B1935 0C, B1935 0D, B1935 0E, B1935 04, or B1935 1F

1. Ignition OFF, disconnect the X1 harness connector at the HSM.
2. Test for 3.5 - 11.5 ohms between control circuit terminal 6 and control circuit terminal 1. 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. 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 19 X4 and the low reference circuit terminal 5 X2. 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. 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. 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. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HSM.
8. If all circuits test normal, replace the HSM.

B2180 0A, B2180 0B, B2180 0C, B2180 0D, B2180 0E, B2180 04, or B2180 1F

1. Ignition OFF, disconnect the X1 harness connector at the HSM.
2. Test for 3.5 - 11.5 ohms between control circuit terminal 3 and control circuit terminal 4. 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. 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 - 300 kohms between the signal circuit terminal 10 X4 and the low reference circuit terminal 7 X2. 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. 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. 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. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HSM.
8. If all circuits test normal, replace the HSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver or Passenger Seat Back Cushion Heater Replacement (Escalade with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (Tahoe with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system__driver-or-passenger-seat-back-cushion)
2. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the HSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When the heated seat function is active, the heated seat module (HSM) supplies battery voltage through the element supply voltage circuit to the seat heater elements. The module controls the seat temperature by providing a PWM ground through the heated seat element control circuit to the seat heater elements. The module then monitors the current flow through the heating element and the temperature sensor rate of change to verify correct operation.

The HSM must be powered and the heated seat must be enabled.

The module does not detect a temperature change within 210 seconds.

The module detects that the set point temperature has not been reached within 8.5 minutes.

By measuring output current, the module calculates that the heating element resistance is below the minimum resistance.

By measuring output current, the module calculates that the heating element resistance is above the maximum resistance.

The temperature sensor voltage is erratic or changes suddenly.

The heated seat back function for the affected seat will be disabled.

1. The current DTC clears when the malfunction is no longer present and the power mode changes to OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

B1935 0A, B1935 0B, B1935 0C, B1935 0D, B1935 0E, B1935 04, or B1935 1F

1. Ignition OFF, disconnect the X1 harness connector at the HSM.
2. Test for 3.5 - 11.5 ohms between control circuit terminal 3 and control circuit terminal 1. 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. 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 19 X4 and the low reference circuit terminal 5 X2. 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. 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. 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. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HSM.
8. If all circuits test normal, replace the HSM.

B2180 0A, B2180 0B, B2180 0C, B2180 0D, B2180 0E, B2180 04, or B2180 1F

1. Ignition OFF, disconnect the X1 harness connector at the HSM.
2. Test for 3.5 - 11.5 ohms between control circuit terminal 6 and control circuit terminal 4. 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. 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. 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. 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. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HSM. 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.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver or Passenger Seat Back Cushion Heater Replacement (Escalade with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (Tahoe with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system__driver-or-passenger-seat-back-cushion)
2. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the HSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The driver and front passenger seat heating elements are controlled by a common high current relay internal to the memory seat module (MSM) and the low side by individual element control circuits. The MSM connects the heated seat heater element supply voltage circuits for both seats to a common reference point. This reference point is biased to approximately 2.5 V. Before the MSM will allow heated seat operation, it checks to see if this reference voltage is shorted to ground or battery voltage. Once the module verifies that it is not closing to a shorted heating element, it allows heated seat operation. After which it continues to monitor for a shorted circuit.

The MSM must be powered.

B2345 00

After a heated seat is activated, the MSM detects a shorted circuit on the seat heating element supply voltage circuit or control circuit.

B2345 13

Any of the temperature sensor inputs remains below 1.5 V for a seat back or 0.95 V for a seat cushion more than 1 second.

B2345 42

This DTC will set if the module calibration is not programmed.

B2345 4B

This DTC will set if the module calibration is out of range.

The heated seat functions for both seats will be disabled.

1. The current DTC clears when the malfunction is no longer present and the power mode changes to OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Verify the type of vehicle and the heated seat system for which the DTC set.

1. If the DTC set in a vehicle equipped with memory, refer to Circuit/System Testing below.
2. If the DTC set in a hybrid vehicle without memory, refer to DTC B2345 (HP2 w/o memory).
3. If the DTC set in a non-hybrid vehicle without memory, refer to DTC B2345 (Dealer installed).
4. If the DTC set in the rear heated seat module, refer to DTC B2345 (Rear seat).

1. Ignition OFF, disconnect the X1, X4 harness connectors at the MSM.
2. Test for infinite resistance between the control circuit terminal 14 X1 and ground. If not the specified value, test the control circuits listed below for a short to ground: Driver seat cushion and seat back terminal 14 X1 Driver seat cushion element terminal 11 X1 Driver seat back element terminal 1 X1
3. Test for infinite resistance between the control circuit terminal 6 X1 and ground. If not the specified value, test the control circuits listed below for a short to ground: Passenger seat cushion and seat back terminal 6 X1 Passenger seat cushion element terminal 14 X4 Passenger seat back element terminal 4 X1
4. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 14 X1 and ground. If the test lamp illuminates, test the control circuits listed below for a short to voltage: Driver seat cushion and seat back terminal 14 X1 Driver seat cushion element terminal 11 X1 Driver seat back element terminal 1 X1
5. Verify that a test lamp does not illuminate between the control circuit terminal 6 X1 and ground. If the test lamp illuminates, test the control circuits listed below for a short to voltage: Passenger seat cushion and seat back terminal 6 X1 Passenger seat cushion element terminal 14 X4 Passenger seat back element terminal 4 X1
6. If all circuits test normal, replace the MSM.

1. Ignition OFF, disconnect the X2, X5 harness connectors at the MSM.
2. Test for greater than 850 ohms between the signal circuit and the low reference circuits listed below: Driver seat cushion terminal 1 X5 and terminal 3 X2 Passenger seat cushion terminal 2 X5 and terminal 6 X2 If less than the specified value, test for a short between the signal and low reference circuits. If the circuits test normal, replace the appropriate seat cushion heater element/temperature sensor.
3. Test for greater than 850 ohms between the signal and the low reference circuits listed below: Driver seat back terminal 4 X5 and terminal 2 X2 Passenger seat back terminal 3 X5 and terminal 5 X2 If less than the specified value, test for a short between the signal and low reference circuits. If the circuits test normal, replace the appropriate seat back heater element/temperature sensor.
4. If all circuits test normal, replace the MSM.

B2345 42 or B2345 4B

If either DTC is set, replace the MSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver or Passenger Seat Back Cushion Heater Replacement (Escalade with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (Tahoe with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system__driver-or-passenger-seat-back-cushion)
2. «Driver or Passenger Seat Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Cushion Heater Replacement (with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
3. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the MSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The front seat heating elements are controlled by a common high current relay internal to the heated seat control module (HSM) and on the low side by individual element control circuits. The HSM connects the seat heater element supply voltage circuits to a common reference point. This reference point is biased to approximately 2.5 V. Before the HSM will allow heated seat operation, it checks to see if the heating element supply voltage circuits and control circuits are shorted to ground or battery voltage. Once the HSM verifies that it is not closing into a shorted heating element, it allows heated seat operation. After which it continues to monitor for a shorted circuit.

The HSM must be powered.

After a heated seat is activated, the HSM detects a shorted circuit on the seat heating element supply voltage circuit or control circuit.

Any of the temperature sensor inputs remains below 1.45 V for more than 1 second.

The current sensing calibration is not programmed.

The current sensing calibration is out of range.

The heated seat function for both seats will be disabled.

1. The current DTC clears when the malfunction is no longer present and the power mode changes to OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Verify the type of vehicle and the heated seat system for which the DTC set.

1. If the DTC set in a hybrid vehicle without memory, refer to Circuit/System Testing below.
2. If the DTC set in a vehicle equipped with memory, refer to DTC B2345 (w/o HP2 with memory).
3. If the DTC set in a non-hybrid vehicle without memory, refer to DTC B2345 (Dealer installed).
4. If the DTC set in the rear heated seat module, refer to DTC B2345 (Rear seat).

1. Ignition OFF, disconnect the X1 harness connector at the HSM.
2. Test for infinite resistance between the control circuit terminal 6 and ground. If not the specified value, test the control circuits listed below for a short to ground: Driver seat cushion and seat back terminal 6 Driver seat cushion element terminal 5 Driver seat back element terminal 1
3. Test for infinite resistance between the control circuit terminal 3 and ground. If not the specified value, test the control circuits listed below for a short to ground: Passenger seat cushion and seat back terminal 3 Passenger seat cushion element terminal 2 Passenger seat back element terminal 4
4. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 6 and ground. If the test lamp illuminates, test the control circuits listed below for a short to voltage: Driver seat cushion and seat back terminal 6 Driver seat cushion element terminal 5 Driver seat back element terminal 1
5. Verify that a test lamp does not illuminate between the supply voltage circuit terminal 3 and ground. If the test lamp illuminates, test the control circuits listed below for a short to voltage: Passenger seat cushion and seat back terminal 3 Passenger seat cushion element terminal 2 Passenger seat back element terminal 4
6. If all circuits test normal, replace the HSM.

1. Ignition OFF, disconnect the X2, X4 harness connectors at the HSM.
2. Test for greater than 850 ohms between the signal and the low reference circuits listed below: Driver seat cushion terminal 9 X4 and terminal 6 X2 Passenger seat cushion terminal 20 X4 and terminal 8 X2 If less than the specified value, test for a short between the signal and low reference circuits. If the circuits test normal, replace the appropriate seat cushion heater element/temperature sensor.
3. Test for greater than 850 ohms between the signal and the low reference circuits listed below: Driver seat back terminal 19 X4 and terminal 5 X2 Passenger seat back terminal 10 X4 and terminal 7 X2 If less than the specified value, test for a short between the signal and low reference circuits. If the circuits test normal, replace the appropriate seat back heater element/temperature sensor.
4. If all circuits test normal, replace the HSM.

If either DTC is set, replace the HSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver or Passenger Seat Back Cushion Heater Replacement (Escalade with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (Tahoe with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system__driver-or-passenger-seat-back-cushion)
2. «Driver or Passenger Seat Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Cushion Heater Replacement (with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
3. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the HSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The front seat heating elements are controlled by a common high current relay internal to the heated seat control module (HSM) and on the low side by individual element control circuits. The HSM connects the seat heater element supply voltage circuits to a common reference point. This reference point is biased to approximately 2.5 V. Before the HSM will allow heated seat operation, it checks to see if the heating element supply voltage circuits and control circuits are shorted to ground or battery voltage. Once the HSM verifies that it is not closing into a shorted heating element, it allows heated seat operation. After which it continues to monitor for a shorted circuit.

The HSM must be powered.

After a heated seat is activated, the HSM detects a shorted circuit on the seat heating element supply voltage circuit or control circuit.

Any of the temperature sensor inputs remains below 1.45 V for more than 1 second.

The current sensing calibration is not programmed.

The current sensing calibration is out of range.

The heated seat function for both seats will be disabled.

1. The current DTC clears when the malfunction is no longer present and the power mode changes to OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition OFF, disconnect the X1 harness connector at the HSM.
2. Test for infinite resistance between the control circuit terminal 3 and ground. If not the specified value, test the control circuits listed below for a short to ground: Driver seat cushion and seat back element terminal 3 Driver seat cushion element terminal 5 Driver seat back element terminal 1
3. Test for infinite resistance between the control circuit terminal 6 and ground. If not the specified value, test the control circuits listed below for a short to ground: Passenger seat cushion and seat back element terminal 6 Passenger seat cushion element terminal 2 Passenger seat back element terminal 4
4. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 3 and ground. If the test lamp illuminates, test the control circuits listed below for a short to voltage: Driver seat cushion and seat back element terminal 3 Driver seat cushion element terminal 5 Driver seat back element terminal 1
5. Verify that a test lamp does not illuminate between the supply voltage circuit terminal 6 and ground. If the test lamp illuminates, test the control circuits listed below for a short to voltage: Passenger seat cushion and seat back element terminal 6 Passenger seat cushion element terminal 2 Passenger seat back element terminal 4
6. If all circuits test normal, replace the HSM.

1. Ignition OFF, disconnect the X2, X4 harness connectors at the HSM.
2. Test for greater than 850 ohms between the signal and the low reference circuits listed below: Driver seat cushion terminal 9 X4 and terminal 6 X2 Passenger seat cushion terminal 20 X4 and terminal 8 X2 If less than the specified value, test for a short between the signal and low reference circuits. If the circuits test normal, replace the appropriate seat cushion heater element/temperature sensor.
3. Test for greater than 850 ohms between the signal and the low reference circuits listed below: Driver seat back terminal 19 X4 and terminal 5 X2 Passenger seat back terminal 10 X4 and terminal 7 X2 If less than the specified value, test for a short between the signal and low reference circuits. If the circuits test normal, replace the appropriate seat back heater element/temperature sensor.
4. If all circuits test normal, replace the HSM.

If either DTC is set, replace the HSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver or Passenger Seat Back Cushion Heater Replacement (Escalade with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (Tahoe with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system__driver-or-passenger-seat-back-cushion)
2. «Driver or Passenger Seat Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Cushion Heater Replacement (with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
3. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the HSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The front seat heating elements are controlled by a common high current relay internal to the rear heated seat control module (RHSM) and on the low side by individual element control circuits. The RHSM connects the seat heater element supply voltage circuits to a common reference point. This reference point is biased to approximately 2.5 V. Before the RHSM will allow heated seat operation, it checks to see if the heating element supply voltage circuits and control circuits are shorted to ground or battery voltage. Once the RHSM verifies that it is not closing into a shorted heating element, it allows heated seat operation. After which it continues to monitor for a shorted circuit.

The RHSM must be powered.

After a heated seat is activated, the RHSM detects a shorted circuit on the seat heating element supply voltage circuit or control circuit.

Any of the temperature sensor inputs remains below 1.45 V for more than 1 second.

The current sensing calibration is not programmed.

The current sensing calibration is out of range.

The heated seat function for both seats will be disabled.

1. The current DTC clears when the malfunction is no longer present and the power mode changes to OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Verify the type of vehicle and the heated seat system for which the DTC set.

1. If the DTC set in the rear heated seat module, refer to Circuit/System Testing below.
2. If the DTC set in a vehicle equipped with memory, refer to DTC B2345 (w/o HP2 with memory).
3. If the DTC set in a hybrid vehicle without memory, refer to DTC B2345 (HP2 w/o memory).
4. If the DTC set in a non-hybrid vehicle without memory, refer to DTC B2345 (Dealer Installed).

1. Ignition OFF, disconnect the X1 harness connector at the RHSM.
2. Test for infinite resistance between the control circuit terminal 3 and ground. If not the specified value, test the control circuits listed below for a short to ground: Left rear seat heater element terminal 3 Left rear seat heater element terminal 5
3. Test for infinite resistance between the control circuit terminal 6 and ground. If not the specified value, test the control circuits listed below for a short to ground: Right rear seat heater element terminal 6 Right rear seat heater element terminal 2
4. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 3 and ground. If the test lamp illuminates, test the control circuits listed below for a short to voltage: Left rear seat heater element terminal 3 Left rear seat heater element terminal 5
5. Verify that a test lamp does not illuminate between the supply voltage circuit terminal 6 and ground. If the test lamp illuminates, test the control circuits listed below for a short to voltage: Right rear seat heater element terminal 6 Right rear seat heater element terminal 2
6. If all circuits test normal, replace the RHSM.

1. Ignition OFF, disconnect the X2, X4 harness connectors at the RHSM.
2. Test for greater than 850 ohms between the signal and the low reference circuits listed below: Left rear seat terminal 9 X4 and terminal 6 X2 Right rear seat terminal 20 X4 and terminal 8 X2 If less than the specified value, test for a short between the signal and low reference circuits. If the circuits test normal, replace the appropriate seat cushion heater element/temperature sensor.
3. If all circuits test normal, replace the RHSM.

If either DTC is set, replace the RHSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Rear Seat Cushion Heater Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
2. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the RHSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The driver and front passenger heated seats are controlled by the memory seat module (MSM). When active, power is applied to the seat cushion and seat back heater elements through a common voltage supply circuit. The module controls the seat temperature by providing a pulse width modulated (PWM) ground through the heated seat element control circuits to the seat heater elements. The module then monitors the current flow through the heating elements and the of rate change of the temperature sensors to verify correct heated seat operation.

The MSM must be powered.

B2425 04 or B2430 04

The module does not detect a temperature change within 210 seconds.

B2425 0A or B2430 0A

The module detects that the set point temperature has not been reached within 8.5 minutes.

B2425 0B, B2425 0E, B2430 0B, or B2430 0E

By measuring output current, the module calculates that the heating element resistance is below the minimum resistance.

B2425 0C, B2425 0D, B2430 0C, or B2430 0D

By measuring output current, the module calculates that the heating element resistance is above the maximum resistance.

B2425 1F or B2430 1F

The temperature sensor voltage is erratic or changes suddenly.

The heated seat cushion function for the affected seat will be disabled.

1. The current DTC clears when the malfunction is no longer present, and the power mode changes to OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Verify the type of vehicle and the heated seat system for which the DTC set.

1. If the DTC set in a vehicle equipped with memory, refer to Circuit/System Testing below.
2. If the DTC set in a hybrid vehicle without memory, refer to DTC B2425 or B2430 (HP2 w/o memory).
3. If the DTC set in a non-hybrid vehicle without memory, refer to DTC B2425 or B2430 (Dealer installed).
4. If the DTC set in the rear heated seat module, refer to DTC B2425 or B2430 (Rear seat).

B2425 0A, B2425 0B, B2425 0C, B2425 0D, B2425 0E, B2425 04, or B2425 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. 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.
4. Test for 2.0 - 8.0 ohms between control circuit terminal 14 and control circuit terminal 11. If less than the specified range, test for a short between the control circuits. If the circuits test normal, replace the seat cushion heater element. If greater than the specified range, test the control circuits for an open/high resistance. If the circuits test normal replace the seat cushion heater element.
5. Disconnect the X2, X5 harness connectors at the MSM.
6. Test for 850 ohms - 300 kohms between the signal circuit terminal 1 X5 and the low reference circuit terminal 3 X2. 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 cushion heater element/temperature sensor. 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 cushion heater element/temperature sensor.
7. Connect the X1, X2, X5 harness connectors at the MSM.
8. Disconnect the harness connector at the seat cushion heater element/temperature sensor.
9. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground. 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. 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.

B2430 0A, B2430 0B, B2430 0C, B2430 0D, B2430 0E, B2430 04, or B2430 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. 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, X4 harness connectors at the MSM.
4. Test for 2.0 - 8.0 ohms between control circuit terminal 6 X1 and control circuit terminal 14 X4. If less than the specified range, test for a short between the control circuits. If the circuits test normal, replace the seat cushion heater element. If greater than the specified range, test the control circuits for an open/high resistance. If the circuits test normal replace the seat cushion heater element.
5. Disconnect the X2, X5 harness connectors at the MSM.
6. Test for 850 ohms - 300 kohms between the signal circuit terminal 2 X5 and the low reference circuit terminal 6 X2. 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 cushion heater element/temperature sensor. 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 cushion heater element/temperature sensor.
7. Connect the X1, X2, X4, X5 harness connectors at the MSM.
8. Disconnect the harness connector at the seat cushion heater element/temperature sensor.
9. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the MSM. 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.
10. If all circuits test normal, replace the MSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver or Passenger Seat Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Cushion Heater Replacement (with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
2. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the MSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When the heated seat function is active, the heated seat module (HSM) supplies battery voltage through the element supply voltage circuit to the seat heater elements. The HSM controls the seat temperature by providing a pulse width modulated (PWM) ground through the heated seat element control circuit to the seat heater elements. The HSM then monitors the current flow through the heating element and the temperature sensor rate of change to verify correct operation.

The HSM must be powered and the heated seat must be enabled.

The HSM does not detect a temperature change within 210 seconds.

The HSM detects that the set point temperature has not been reached within 8.5 minutes.

By measuring output current, the HSM calculates that the heating element resistance is below the minimum resistance.

B2425 0C, B2445 0D, B2430 0C, or B2430 0D

By measuring output current, the HSM calculates that the heating element resistance is above the maximum resistance.

The temperature sensor voltage is erratic or changes suddenly.

The heated seat cushion function for the affected seat will be disabled.

1. The current DTC clears when the malfunction is no longer present, and the power mode changes to OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Verify the type of vehicle and the heated seat system for which the DTC set.

1. If the DTC set in a hybrid vehicle without memory, refer to Circuit/System Testing below.
2. If the DTC set in a vehicle equipped with memory, refer to DTC B2425 or B2430 (w/o HP2 with memory).
3. If the DTC set in a non-hybrid vehicle without memory, refer to DTC B2425 or B2430 (Dealer installed).
4. If the DTC set in the rear heated seat module, refer to DTC B2425 or B2430 (Rear seat).

B2425 0A, B2425 0B, B2425 0C, B2425 0D, B2425 0E, B2425 04, or B2425 1F

1. Ignition OFF, disconnect the X1 harness connector at the HSM.
2. Test for 2.0 - 8.0 ohms between control circuit terminal 6 and control circuit terminal 5. If less than the specified range, test for a short between the control circuits. If the circuits test normal, replace the seat cushion heater element. If greater than the specified range, test the control circuits for an open/high resistance. If the circuits test normal replace the seat cushion heater element.
3. Disconnect the X2, X4 harness connectors at the HSM.
4. Test for 850 - 300 kohms between the signal circuit terminal 9 X4 and the low reference circuit terminal 6 X2. 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 cushion heater element/temperature sensor. 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 cushion heater element/temperature sensor.
5. Connect the X1, X2, X4 harness connectors at the HSM.
6. Disconnect the harness connector at the seat cushion heater element/temperature sensor.
7. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground. 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. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HSM.
8. If all circuits test normal, replace the HSM.

B2430 0A, B2430 0B, B2430 0C, B2430 0D, B2430 0E, B2430 04, or B2430 1F

1. Ignition OFF, disconnect the X1 harness connector at the HSM.
2. Test for 2.0 - 8.0 ohms between control circuit terminal 3 and control circuit terminal 2. If less than the specified range, test for a short between the control circuits. If the circuits test normal, replace the seat cushion heater element. If greater than the specified range, test the control circuits for an open/high resistance. If the circuits test normal, replace the seat cushion heater element.
3. Disconnect the X2, X4 harness connectors at the HSM.
4. Test for 850 ohms - 300 kohms between the signal circuit terminal 20 X4 and the low reference circuit terminal 8 X2. 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 cushion heater element/temperature sensor. 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 cushion heater element/temperature sensor.
5. Connect the X1, X2, X4 harness connectors at the HSM.
6. Disconnect the harness connector at the seat cushion heater element/temperature sensor.
7. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground. 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. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HSM.
8. If all circuits test normal, replace the HSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver or Passenger Seat Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Cushion Heater Replacement (with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
2. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the HSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When the heated seat function is active, the heated seat module (HSM) supplies battery voltage through the element supply voltage circuit to the seat heater elements. The HSM controls the seat temperature by providing a pulse width modulated (PWM) ground through the heated seat element control circuit to the seat heater elements. The HSM then monitors the current flow through the heating element and the temperature sensor rate of change to verify correct operation.

The HSM must be powered and the heated seat must be enabled.

The HSM does not detect a temperature change within 210 seconds.

The HSM detects that the set point temperature has not been reached within 8.5 minutes.

By measuring output current, the HSM calculates that the heating element resistance is below the minimum resistance.

By measuring output current, the HSM calculates that the heating element resistance is above the maximum resistance.

The temperature sensor voltage is erratic or changes suddenly.

The heated seat cushion function for the affected seat will be disabled.

1. The current DTC clears when the malfunction is no longer present, and the power mode changes to OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

B2425 0A, B2425 0B, B2425 0C, B2425 0D, B2425 0E, B2425 04, or B2425 1F

1. Ignition OFF, disconnect the X1 harness connector at the HSM.
2. Test for 2.0 - 8.0 ohms between control circuit terminal 3 and control circuit terminal 5. If less than the specified range, test for a short between the control circuits. If the circuits test normal, replace the seat cushion heater element. If greater than the specified range, test the control circuits for an open/high resistance. If the circuits test normal replace the seat cushion heater element.
3. Disconnect the X2, X4 harness connectors at the HSM.
4. Test for 850 ohms - 300 kohms between the signal circuit terminal 9 X4 and the low reference circuit terminal 6 X2. 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 cushion heater element/temperature sensor. 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 cushion heater element/temperature sensor.
5. Connect the X1, X2, X4 harness connectors at the HSM.
6. Disconnect the harness connector at the seat cushion heater element/temperature sensor.
7. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HSM. 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.

B2430 0A, B2430 0B, B2430 0C, B2430 0D, B2430 0E, B2430 04, or B2430 1F

1. Ignition OFF, disconnect the X1 harness connector at the HSM.
2. Test for 2.0 - 8.0 ohms between control circuit terminal 6 and control circuit terminal 2. If less than the specified range, test for a short between the control circuits. If the circuits test normal, replace the seat cushion heater element. If greater than the specified range, test the control circuits for an open/high resistance. If the circuits test normal, replace the seat cushion heater element.
3. Disconnect the X2, X4 harness connectors at the HSM.
4. Test for 850 ohms - 300 kohms between the signal circuit terminal 20 X4 and the low reference circuit terminal 8 X2. 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 cushion heater element/temperature sensor. 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 cushion heater element/temperature sensor.
5. Connect the X1, X2, X4 harness connectors at the HSM.
6. Disconnect the harness connector at the seat cushion heater element/temperature sensor.
7. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground. 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. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HSM.
8. If all circuits test normal, replace the HSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver or Passenger Seat Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Cushion Heater Replacement (with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
2. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the HSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When the heated seat function is active, the rear heated seat module (RHSM) supplies battery voltage through the element supply voltage circuit to the seat heater elements. The RHSM controls the seat temperature by providing a pulse width modulated (PWM) ground through the heated seat element control circuit to the seat heater elements. The RHSM then monitors the current flow through the heating element and the temperature sensor rate of change to verify correct operation.

The RHSM must be powered and the heated seat must be enabled.

The RHSM does not detect a temperature change within 210 seconds.

The RHSM detects that the set point temperature has not been reached within 8.5 minutes.

By measuring output current, the RHSM calculates that the heating element resistance is below the minimum resistance.

By measuring output current, the RHSM calculates that the heating element resistance is above the maximum resistance.

The temperature sensor voltage is erratic or changes suddenly.

The heated seat cushion function for the affected seat will be disabled.

1. The current DTC clears when the malfunction is no longer present, and the power mode changes to OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Verify the type of vehicle and the heated seat system for which the DTC set.

1. If the DTC set in the rear heated seat module, refer to Circuit/System Testing below.
2. If the DTC set in a vehicle equipped with memory, refer to DTC B2425 or B2430 (w/o HP2 with memory).
3. If the DTC set in a hybrid vehicle without memory, refer to DTC B2425 or B2430 (HP2 w/o memory).
4. If the DTC set in a non-hybrid vehicle without memory, refer to DTC B2425 or B2430 (Dealer installed).

B2425 0A, B2425 0B, B2425 0C, B2425 0D, B2425 0E, B2425 04, or B2425 1F

1. Ignition OFF, disconnect the X1 harness connector at the RHSM.
2. Test for 2.5 - 8.5 ohms between control circuit terminal 3 and control circuit terminal 5. If less than the specified range, test for a short between the control circuits. If the circuits test normal, replace the seat cushion heater element. If greater than the specified range, test the control circuits for an open/high resistance. If the circuits test normal replace the seat cushion heater element.
3. Disconnect the X2, X4 harness connectors at the RHSM.
4. Test for 850 ohms - 300 kohms between the signal circuit terminal 9 X4 and the low reference circuit terminal 6 X2. 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 cushion heater element/temperature sensor. 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 cushion heater element/temperature sensor.
5. Connect the X1, X2, X4 harness connectors at the RHSM.
6. Disconnect the harness connector at the seat cushion heater element/temperature sensor.
7. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground. 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 RHSM. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the RHSM.
8. If all circuits test normal, replace the RHSM.

B2430 0A, B2430 0B, B2430 0C, B2430 0D, B2430 0E, B2430 04, or B2430 1F

1. Ignition OFF, disconnect the X1 harness connector at the RHSM.
2. Test for 3.5 - 11.5 ohms between control circuit terminal 6 and control circuit terminal 2. If less than the specified range, test for a short between the control circuits. If the circuits test normal, replace the seat cushion heater element. If greater than the specified range, test the control circuits for an open/high resistance. If the circuits test normal, replace the seat cushion heater element.
3. Disconnect the X2, X4 harness connectors at the RHSM.
4. Test for 850 ohms - 300 kohms between the signal circuit terminal 20 X4 and the low reference circuit terminal 8 X2. 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 cushion heater element/temperature sensor. 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 cushion heater element/temperature sensor.
5. Connect the X1, X2, X4 harness connectors at the RHSM.
6. Disconnect the harness connector at the seat cushion heater element/temperature sensor.
7. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the RHSM. 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 RHSM.
8. If all circuits test normal, replace the RHSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Rear Seat Cushion Heater Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
2. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the RHSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The heated seat temperature sensor is located in the seat back just under the seat cover with the seat heating element. The temperature sensor is a 2 wire thermistor and resistance through the sensor varies with temperature. The signal circuit is referenced from 5 V within the memory seat module (MSM) and the temperature of the seat surface determines the signal circuit voltage. Once the seat reaches the set temperature, the module will then cycle the control circuits of the heating elements ON and OFF in order to maintain the desired seat temperature based on the feedback voltage from the sensors.

The heated seat system must be active.

B2435 02 or B2440 02

The temperature sensor voltage drops below 0.8 volt for more than 1 second.

B2435 05 or B2440 05

The temperature sensor voltage is greater than 5 V for more than 1 second.

The heated seat function for the appropriate seat will be disabled.

1. The current DTC will clear 3 seconds after the reference voltage returns to normal operating range, and the ignition is cycled OFF then back to ACC or RUN.
2. A history DTC will clear after 50 ignition cycles or with a scan tool using the clear DTCs function.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Verify the type of vehicle and the heated seat system for which the DTC set.

1. If the DTC set in a vehicle equipped with memory, refer to Circuit/System Testing below.
2. If the DTC set in a hybrid or a non-hybrid vehicle without memory, refer to DTC B2435 or B2440 (HP2 or dealer installed w/o memory).

B2435 02 or B2435 05

1. Ignition OFF, disconnect the X2, X5 harness connectors at the MSM.
2. Test for 850 ohms - 300 kohms between the signal circuit terminal 4 X5 and the low reference circuit terminal 2 X2. 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. 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.
3. Connect the X2, X5 harness connectors at the MSM.
4. Disconnect the harness connector at the seat back heater element/temperature sensor.
5. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground. 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. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the MSM.
6. If all circuits test normal, replace the MSM.

B2440 02 or B2440 05

1. Ignition OFF, disconnect the X2, X5 harness connectors at the MSM.
2. Test for 850 ohms - 300 kohms between the signal circuit terminal 3 X5 and the low reference circuit terminal 5 X2. 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. 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.
3. Connect the X2, X5 harness connectors at the MSM.
4. Disconnect the harness connector at the seat back heater element/temperature sensor.
5. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground. 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. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the MSM.
6. If all circuits test normal, replace the MSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver or Passenger Seat Back Cushion Heater Replacement (Escalade with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (Tahoe with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system__driver-or-passenger-seat-back-cushion)
2. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the MSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The heated seat temperature sensor that set this diagnostic trouble code (DTC) is located in the seat cushion just under the seat cover with the seat heating element. The heated seat module (HSM) supplies a 5 V reference voltage through the temperature sensor signal circuit and a ground through the low reference circuit to the sensor. The HSM monitors the voltage of the sensor signal circuit to determine the temperature of the seat. The temperature sensor varies in resistance based on the temperature of the heating element causing the signal voltage to change. Once the seat reaches the set temperature, the HSM will then cycle the control circuits of the heating elements ON and OFF in order to maintain the desired seat temperature based on the feedback voltage from the sensor.

The HSM must be powered.

The temperature sensor voltage drops below 0.8 V for more than 1 second.

The temperature sensor voltage is greater than 5 V for more than 1 second.

The heated seat back function for the affected seat will be disabled.

1. The current DTC will clear 3 seconds after the reference voltage returns to normal operating range, and the ignition is cycled OFF then back to ACC or RUN.
2. A history DTC will clear after 50 ignition cycles or with a scan tool using the clear DTCs function.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Verify the type of vehicle and the heated seat system for which the DTC set.

1. If the DTC set in a hybrid or a non-hybrid vehicle without memory, refer to Circuit/System Testing below.
2. If the DTC set in a vehicle equipped with memory, refer to DTC B2435 or B2440 (w/o HP2 with memory).

B2435 02 or B2435 05

1. Ignition OFF, disconnect the X2, X4 harness connectors at the HSM.
2. Test for 850 ohms - 300 kohms between the signal circuit terminal 19 X4 and the low reference circuit terminal 5 X2. 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. 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.
3. Connect the X2, X4 harness connectors at the HSM.
4. Disconnect the harness connector at the seat back heater element/temperature sensor.
5. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground. 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. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HSM.
6. If all circuits test normal, replace the HSM.

B2440 02 or B2440 05

1. Ignition OFF, disconnect the X2, X4 harness connectors at the HSM.
2. Test for 850 ohms - 300 kohms between the signal circuit terminal 10 X4 and the low reference circuit terminal 7 X2. 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. 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.
3. Connect the X2, X4 harness connectors at the HSM.
4. Disconnect the harness connector at the seat back heater element/temperature sensor.
5. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal C and ground. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HSM. 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.
6. If all circuits test normal, replace the HSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver or Passenger Seat Back Cushion Heater Replacement (Escalade with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (Tahoe with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system__driver-or-passenger-seat-back-cushion)
2. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the HSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The driver and front passenger heated seat heating elements are controlled by a common high current relay internal to the memory seat module (MSM) and the low side by individual element control circuits. The MSM connects the heated seat heater element supply voltage circuits for both seats to a common reference point. This reference point is biased to approximately 2.5 V. Before the MSM will allow heated seat operation, it checks to see if this reference voltage is shorted to ground or battery voltage. Once the MSM verifies that it is not closing to a shorted heating element, it allows heated seat operation. After which it continues to monitor for a shorted circuit.

The MSM must be powered.

B2508 02

Before the heated seats are activated, the MSM detects a short to ground on the seat heating element supply voltage circuit or control circuit.

B2508 01

Before the heated seats are activated, the MSM detects a short to battery voltage on the seat heating element supply voltage circuit or control circuit.

The heated seat function for both seats will be disabled.

1. The current DTC clears when the malfunction is no longer present and the power mode changes to OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Verify the type of vehicle and the heated seat system for which the DTC set.

1. If the DTC set in a vehicle equipped with memory, refer to Circuit/System Testing below.
2. If the DTC set in a hybrid vehicle without memory, refer to DTC B2508 or B2509 (HP2 w/o memory).
3. If the DTC set in a non-hybrid vehicle without memory, refer to DTC B2508 or B2509 (Dealer installed).
4. If the DTC set in the rear heated seat module, refer to DTC B2508 or B2509 (Rear seat).

1. Ignition OFF, disconnect the X1, X4 harness connectors at the MSM.
2. Test for infinite resistance between the control circuit terminal 14 X1 and ground. If not the specified value, test the control circuits listed below for a short to ground: Driver seat cushion and back element terminal 14 X1 Driver seat cushion element terminal 11 X1 Driver seat back element terminal 1 X1
3. Test for infinite resistance between the control circuit terminal 6 X1 and ground. If not the specified value, test the control circuits listed below for a short to ground: Passenger seat cushion and back element terminal 6 X1 Passenger seat cushion element terminal 14 X4 Passenger seat back element terminal 4 X1
4. Ignition ON, verify that a test lamp does not illuminate between the supply voltage circuit terminal 14 X1 and ground. If the test lamp illuminates, test the control circuits listed below for a short to voltage: Driver seat cushion and back element terminal 14 X1 Driver seat cushion element terminal 11 X1 Driver seat back element terminal 1 X1
5. Verify that a test lamp does not illuminate between the supply voltage circuit terminal 6 X1 and ground. If the test lamp illuminates, test the control circuits listed below for a short to voltage: Passenger seat cushion and back element terminal 6 X1 Passenger seat cushion element terminal 14 X4 Passenger seat back element terminal 4 X1
6. If all circuits test normal, replace the MSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver or Passenger Seat Back Cushion Heater Replacement (Escalade with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (Tahoe with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system__driver-or-passenger-seat-back-cushion)
2. «Driver or Passenger Seat Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Cushion Heater Replacement (with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
3. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the MSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The front seat heating elements are controlled by a common high current relay internal to the heated seat module (HSM) and on the low side by individual element control circuits. The HSM connects the seat heater element supply voltage circuits to a common reference point. This reference point is biased to approximately 2.5 V. Before the HSM will allow heated seat operation, it checks to see if the heating element supply voltage circuits and control circuits are shorted to ground or battery voltage. Once the HSM verifies that it is not closing to a shorted heating element, it allows heated seat operation. After which it continues to monitor for a shorted circuit.

The HSM must be powered.

Before the heated seats are activated, the HSM detects a short to ground on the seat heating element supply voltage circuit or control circuit.

Before the heated seats are activated, the HSM detects a short to battery voltage on the seat heating element supply voltage circuit or control circuit.

The heated seat function for both seats will be disabled.

1. The current DTC clears when the malfunction is no longer present and the power mode changes to OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Verify the type of vehicle and the heated seat system for which the DTC set.

1. If the DTC set in a hybrid vehicle without memory, refer to Circuit/System Testing below.
2. If the DTC set in a vehicle equipped with memory, refer to DTC B2508 or B2509 (w/o HP2 with memory).
3. If the DTC set in a non-hybrid vehicle without memory, refer to DTC B2508 or B2509 (Dealer installed).
4. If the DTC set in the rear heated seat module, refer to DTC B2508 or B2509 (Rear seat).

1. Ignition OFF, disconnect the X1 harness connector at the HSM.
2. Test for infinite resistance between the control circuit terminal 6 and ground. If not the specified value, test the control circuits listed below for a short to ground: Driver seat cushion and back element terminal 6 Driver seat cushion element terminal 5 Driver seat back element terminal 1
3. Test for infinite resistance between the control circuit terminal 3 and ground. If not the specified value, test the control circuits listed below for a short to ground: Passenger seat cushion and back element terminal 3 Passenger seat cushion element terminal 2 Passenger seat back element terminal 4
4. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 6 and ground. If the test lamp illuminates, test the control circuits listed below for a short to voltage: Driver seat cushion and back element terminal 6 Driver seat cushion element terminal 5 Driver seat back element terminal 1
5. Verify that a test lamp does not illuminate between the control circuit terminal 3 and ground. If the test lamp illuminates, test the control circuits listed below for a short to voltage: Passenger seat cushion and back element terminal 3 Passenger seat cushion element terminal 2 Passenger seat back element terminal 4
6. If all circuits test normal, replace the HSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver or Passenger Seat Back Cushion Heater Replacement (Escalade with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (Tahoe with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system__driver-or-passenger-seat-back-cushion)
2. «Driver or Passenger Seat Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Cushion Heater Replacement (with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
3. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the HSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The front seat heating elements are controlled by a common high current relay internal to the heated seat module (HSM) and on the low side by individual element control circuits. The HSM connects the seat heater element supply voltage circuits to a common reference point. This reference point is biased to approximately 2.5 V. Before the HSM will allow heated seat operation, it checks to see if the heating element supply voltage circuits and control circuits are shorted to ground or battery voltage. Once the HSM verifies that it is not closing to a shorted heating element, it allows heated seat operation. After which it continues to monitor for a shorted circuit.

The HSM must be powered.

Before the heated seats are activated, the HSM detects a short to ground on the seat heating element supply voltage circuit or control circuit.

Before the heated seats are activated, the HSM detects a short to battery voltage on the seat heating element supply voltage circuit or control circuit.

The heated seat function for both seats will be disabled.

1. The current DTC clears when the malfunction is no longer present and the power mode changes to OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

B2508 02

1. Ignition OFF, disconnect the X1 harness connector at the HSM.
2. Test for infinite resistance between the control circuit terminal 3 and ground. If not the specified value, test the control circuits listed below for a short to ground: Driver seat cushion and back element terminal 3 Driver seat cushion element terminal 5 Driver seat back element terminal 1
3. Test for infinite resistance between the control circuit terminal 6 and ground. If not the specified value, test the control circuits listed below for a short to ground: Passenger seat cushion and back element terminal 6 Passenger seat cushion element terminal 2 Passenger seat back element terminal 4
4. If all circuits test normal, replace the HSM.

B2508 01

1. Ignition OFF, disconnect the X1 harness connector at the HSM.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 3 and ground. If the test lamp illuminates, test the control circuits listed below for a short to voltage: Driver seat cushion and back element terminal 3 Driver seat cushion element terminal 5 Driver seat back element terminal 1
3. Verify that a test lamp does not illuminate between the control circuit terminal 6 and ground. If the test lamp illuminates, test the control circuits listed below for a short to voltage: Passenger seat cushion and back element terminal 6 Passenger seat cushion element terminal 2 Passenger seat back element terminal 4
4. If all circuits test normal, replace the HSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver or Passenger Seat Back Cushion Heater Replacement (Escalade with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (Tahoe with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Back Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system__driver-or-passenger-seat-back-cushion)
2. «Driver or Passenger Seat Cushion Heater Replacement (without HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Driver or Passenger Seat Cushion Heater Replacement (with HP2)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
3. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the HSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The rear seat heating elements are controlled by a common high current relay internal to the rear heated seat module (RHSM) and on the low side by individual element control circuits. The RHSM connects the seat heater element supply voltage circuits to a common reference point. This reference point is biased to approximately 2.5 V. Before the RHSM will allow heated seat operation, it checks to see if the heating element supply voltage circuits and control circuits are shorted to ground or battery voltage. Once the RHSM verifies that it is not closing to a shorted heating element, it allows heated seat operation. After which it continues to monitor for a shorted circuit.

The RHSM must be powered.

Before the heated seats are activated, the RHSM detects a short to ground on the seat heating element supply voltage circuit or control circuit.

Before the heated seats are activated, the RHSM detects a short to battery voltage on the seat heating element supply voltage circuit or control circuit.

The heated seat function for both seats will be disabled.

1. The current DTC clears when the malfunction is no longer present and the power mode changes to OFF then back to ACC or RUN.
2. The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Verify the type of vehicle and the heated seat system for which the DTC set.

1. If the DTC set in the rear heated seat module, refer to Circuit/System Testing below.
2. If the DTC set in a vehicle equipped with memory, refer to DTC B2508 or B2509 (w/o HP2 with memory).
3. If the DTC set in a hybrid vehicle without memory, refer to DTC B2508 or B2509 (HP2 w/o memory).
4. If the DTC set in a non-hybrid vehicle without memory, refer to DTC B2508 or B2509 (Dealer installed).

1. Ignition OFF, disconnect the X1 harness connector at the RHSM.
2. Test for infinite resistance between the control circuit terminal 3 and ground. If not the specified value, test the control circuits listed below for a short to ground: Left rear seat cushion terminal 3 Left rear seat cushion terminal 5
3. Test for infinite resistance between the control circuit terminal 6 and ground. If not the specified value, test the control circuits listed below for a short to ground: Right rear seat cushion terminal 6 Right rear seat cushion terminal 2
4. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 3 and ground. If the test lamp illuminates, test the control circuits listed below for a short to voltage: Left rear seat cushion terminal 3 Left rear seat cushion terminal 5
5. Verify that a test lamp does not illuminate between the control circuit terminal 6 and ground. If the test lamp illuminates, test the control circuits listed below for a short to voltage: Right rear seat cushion terminal 6 Right rear seat cushion terminal 2
6. If all circuits test normal, replace the RHSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Rear Seat Cushion Heater Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
2. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the RHSM replacement, setup, and programming

Symptoms - Seat Heating and Cooling

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) before using the Symptom Tables in order to verify that all of the following are true: There are no DTCs set. The control modules can communicate via the serial data link.
2. Review the system operation in order to familiarize yourself with the system functions. Refer to the following system descriptions: «Heated Seats Description and Operation (KA1)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) «Heated Seats Description and Operation (KA6)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system__heated-seats-description-and-operation-ka6) «Heated/Cooled Seats Description and Operation»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system__heatedcooled-seats-description-and-operation)

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the system. Refer to «Checking Aftermarket Accessories»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__checking-aftermarket-accessories) .
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

1. «Heated Seat Inoperative (Cadillac)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Heated Seat Inoperative (Chevrolet or GMC, KA1)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
2. «Heated Seat Inoperative - Rear»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
3. «Heated/Cooled Seats Inoperative (Cadillac, KB6)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system) or «Heated/Cooled Seats Inoperative (Chevrolet or GMC, KB6)»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The driver and front passenger heated seats are controlled by separate heated seat switches that are located on the HVAC panel. When a heated seat switch is pressed, a serial data message is sent from the HVAC control module to the memory seat module (MSM) indicating the heated seat request. In response to this message, the MSM applies battery positive voltage through the element supply voltage circuit to the appropriate seat heating elements. The module controls the seat temperature by providing a PWM ground through the heated seat element control circuits to the seat heater elements. The MSM then sends a serial data message back to the HVAC control module to either illuminate or turn off the appropriate temperature indicators.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, observe the appropriate scan tool Seat 1 or 2 HVC Data parameters listed below while pressing and releasing the appropriate switch. The readings should change from Off to Back and Cushion or Back Only. Driver Seat HVC Mode Passenger Seat HVC Mode If not the specified values and there are no DTCs set, replace the HVAC control module.
2. If all scan tool parameters test normal and there are no DTCs set, replace the MSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for memory seat module and HVAC control module replacement, programming, and setup

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The driver and front passenger heated seats are controlled by separate heated seat switches located on the door panels. When a heated seat switch is pressed, ground is momentarily applied through the switch contacts and the switch signal circuit to the door lock/window switch. In response to this signal, the door lock/window switch sends a serial message to the memory seat module (MSM) or heated seat module (HSM) indicating the heat seat request. The module then applied battery voltage to the seat cushion and seat back heater elements through a common voltage supply circuit. Each individual heater element is grounded by the module through separate low side drive control circuits. The heater element control circuits are pulse width modulated (PWM) to ground by the module in order to control the seat temperatures by regulating the current flow through the heater elements. The MSM/HSM relies on 4 independent inputs from temperature sensors (thermistors) located in the seat back and seat cushion of the driver and passenger seats. The temperature sensor resistance varies based on the temperature of the heating element causing the signal circuit voltage to change. Once the seat reaches the switch set temperature, the MSM/HSM will then cycle the control circuits of the heating elements ON and OFF in order to maintain the desired seat temperature based on the feedback voltage from the sensors. The MSM/HSM then monitors the current flow through the heating elements and the of rate change of the temperature sensor to verify correct heated seat operation.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, observe the appropriate scan tool Driver Door Switch or Passenger Door Switch parameters listed below while pressing and releasing the appropriate switch. The readings should change between Inactive and Active. Seat Back Heat Mode Sw. Seat Heat Mode Sw. If not the specified values, refer to the Heated Seat Switch component test. If the heated seat switch tests normal, test or replace the appropriate door lock/window switch.
2. If all scan tool parameters test normal and there are no DTCs set, replace the MSM/HSM.
3. If all heated seat functions operate normal and the heated seat switch indicators do not illuminate, refer to the Heated Seat Switch Indicators component test.

Component Testing

Heated Seat Switch

1. Ignition OFF, disconnect the X4 harness connector at the door lock/window switch.
2. Test for infinite resistance between the signal circuits listed below and the low reference circuit terminal 4 with the switch in the open position. Seat back and cushion heat mode terminal 6 Seat back only mode terminal 7 If not the specified value, replace the heated seat switch.
3. Test for less than 2 ohms between the signal circuits listed below and the low reference circuit terminal 4 with the switch in the closed position. Seat back and cushion heat mode terminal 6 Seat back only mode terminal 7 If greater than the specified range for any of the tests, replace the heated seat switch.

Heated Seat Switch Indicators

1. Ignition OFF, disconnect the X4 harness connector at the door lock/window switch.
2. Connect a 3 A fused jumper wire between the low reference circuit terminal 4 and ground.
3. Connect a test lamp between B+ and each control circuit listed below. The appropriate indicator should illuminate. Seat back and cushion mode indicator terminal 10 Seat back only mode indicator terminal 11 Low heat indicator terminal 9 Medium heat indicator terminal 1 High heat indicator terminal 2 If any indicator does not illuminate, replace the heated seat switch.
4. If all indicators illuminate, replace the door lock/window switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Front Seat Heater Switch Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
2. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for MSM, HSM and driver or passenger door lock/window switch replacement, programming, and setup

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The left and right rear passenger heated seats are controlled by separate heated seat switches located in the auxiliary heater and air conditioning control module. The heated seats operate in the high and low modes for the seat cushion only. When a heated seat switch is pressed, the auxiliary heater and air conditioning control module illuminates appropriate switch indicators and sends a serial data message to the rear heated seat module (RHSM) indicating the heated seat request. The RHSM then determines the mode of operation and turns the heated seat system ON or OFF.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated Seats Description and Operation (KA1) or Heated Seats Description and Operation (KA6)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Engine running, observe the scan tool Rear HVAC/RSA parameters listed below while pressing and releasing the appropriate heated seat switch. The reading should change between Inactive and Active and the appropriate switch indicators should illuminate. Left Rear Heated Seat Switch Right Rear Heated Seat Switch If not the specified values, replace the auxiliary heater and air conditioning control module. If the scan tool parameters test normal, but, the switch indicators do not illuminate, replace the auxiliary heater and air conditioning control module.
2. If all scan tool parameters test normal and there are no DTCs set, replace the RHSM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for RHSM and auxiliary heater and air conditioning control module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The heat and cool seat functions for both the driver and passenger seats is controlled by the climate control seat module that is located under the passenger seat cushion. The heated and cooled seat switches are located in the HVAC control module. When a heated or cooled seat switch is pressed a serial data message from the HVAC control module is sent to the memory seat module (MSM) indicating the heat/cool seat request. The MSM then sends a pulse width modulation (PWM) signal through the appropriate heated/cooled seat mode signal circuit to the climate control seat module (CCSM) to activate the heated or cooled seat function. The CCSM then applies battery voltage to the seat cushion and seat back thermal electronic devices (TEDs) and a pre-determined voltage to the blower motors. To determine seat temperature, the CCSM supplies a 5 volt signal and a low reference to the temperature sensors that are attached to each TED. The temperature sensors are variable resistors, their resistance changes as the temperature of the seat changes. Then based on the seat temperature, the CCSM controls the voltage level that it applies to the TEDs and blower motors.

Diagnostic Aids

The following conditions must be met in order to perform valid tests when diagnosing the climate control seat system

1. The ignition must be cycled OFF then ON between each test in order to reset the CCSM.
2. The engine must be running in order to supply the CCSM with the amount of current needed to operate the heated/cool seat system.
3. Examine the seat-to-body inline harness connector under affected seat for loose, bent, or backed out terminals.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated/Cooled Seats Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, observe the HVAC control panel while pressing and releasing the appropriate heated or cooled seat switch. The appropriate switch symbol should be displayed on the control panel. If the symbol is not displayed, replace the HVAC control module.
2. Engine running, operate the driver and passenger heated and cooled seats through the modes of operation listed below. The seat should operate in all three modes. Seat back and cushion heat mode Back only heat mode Cool mode If both, the driver and passenger heated/cool seats are inoperative, refer to Driver and Passenger Heated/Cool Seats Inoperative. If the driver heated/cool seat is inoperative, refer to Driver Heated/Cool Seat Circuit System Testing. If the passenger heated/cool seat is inoperative, refer to Passenger Heated/Cool Seat Circuit System Testing.

Driver and Passenger Heated/Cool Seats Inoperative

1. Ignition OFF, disconnect the X1 harness connector at the CCSM.
2. Verify that a test lamp illuminates between the ground circuit terminal M and B+. If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Verify that a test lamp illuminates between the B+ circuit terminal E and ground. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
4. Disconnect the X2 harness connector at the CCSM.
5. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 1 and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
6. If all circuits test normal, replace the CCSM.

Driver Heated/Cool Seat Circuit System Testing

1. Ignition OFF, disconnect the X3 harness connector at the CCSM.
2. Connect a test lamp between the signal circuit terminal 14 and B+.
3. Ignition ON, press the HEAT or COOL seat switch through the high, medium, and low positions to OFF. The test lamp should illuminate until the OFF position is reached. If the test lamp does not illuminate, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the MSM. If the test lamp is ON with the switch in the OFF position, test the signal circuit for a short to ground. If the circuit tests normal, replace the MSM.
4. Connect the X3 harness connector to the CCSM.
5. Disconnect the harness connector at the seat cushion ventilation heating and cooling module.
6. Test for less than 5 ohms between the low reference circuit terminal 4 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the CCSM.
7. Ignition ON, test for 4.8-5.2 V between the signal circuit terminal 5 and ground. 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 CCSM. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
8. Ignition OFF then ON, connect a test lamp between the control circuit terminals listed below and ground. Press the HEAT switch when testing the heat control circuit and the COOL switch when testing the cool control circuit. The test lamp should illuminate or slowly illuminate for approximately 2-4 seconds after the switch is pressed. On the heat control circuit, the test lamp may exhibit a 4 second delay before it starts to illuminate. Seat cushion heat control circuit terminal 1 Seat cushion cool control circuit terminal 3 If the test lamp does not illuminate, test the appropriate control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the CCSM. If the test lamp is always ON, test the appropriate control circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
9. Ignition OFF then ON, connect a test lamp between the control circuit terminals listed below and ground. The test lamp should illuminate or slowly illuminate for approximately 5 seconds after pressing the HEAT switch. Seat cushion blower control circuit terminal 2 Seat cushion blower speed control circuit terminal 7 If the test lamp does not illuminate, test the appropriate control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the CCSM. If the test lamp is always ON, test the appropriate control circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
10. Ignition OFF, connect the harness connector to the seat cushion ventilation heating and cooling module.
11. Disconnect the harness connector at the seat back ventilation heating and cooling module.
12. Test for less than 5 ohms between the low reference circuit terminal 4 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the CCSM.
13. Ignition ON, test for 4.8-5.2 V between the signal circuit terminal 5 and ground. 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 CCSM. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
14. Ignition OFF then ON, connect a test lamp between the control circuit terminals listed below and ground. Press the HEAT switch when testing the heat control circuit and the COOL switch when testing the cool control circuit. The test lamp should illuminate or slowly illuminate for approximately 4 seconds after the switch is pressed. On the heat control circuit, the test lamp may exhibit a 4 second delay before it starts to illuminate. Seat back heat control circuit terminal 1 Seat back cool control circuit terminal 3 If the test lamp does not illuminate, test the appropriate control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the CCSM. If the test lamp is always ON, test the appropriate control circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
15. Ignition OFF then ON, connect a test lamp between the control circuit terminals listed below and ground. The test lamp should illuminate or slowly illuminate for approximately 5 seconds after pressing the HEAT switch. Seat back blower control circuit terminal 2 Seat cushion blower speed control circuit terminal 7 If the test lamp does not illuminate, test the appropriate control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the CCSM. If the test lamp is always ON, test the appropriate control circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
16. If all circuits test normal, test or replace the appropriate seat cushion or seat back ventilation heating and cooling module.

Passenger Heated/Cool Seat Circuit System Testing

1. Ignition OFF, disconnect the X3 harness connector at the CCSM.
2. Connect a test lamp between the signal circuit terminal 6 and B+.
3. Ignition ON, press the HEAT or COOL seat switch through the high, medium, and low positions to OFF. The test lamp should illuminate until the OFF position is reached. If the test lamp does not illuminate, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the MSM. If the test lamp is ON with the switch in the OFF position, test the signal circuit for a short to ground. If the circuit tests normal, replace the MSM.
4. Connect the X3 harness connector to the CCSM.
5. Disconnect the harness connector at the seat cushion ventilation heating and cooling module.
6. Test for less than 5 ohms between the low reference circuit terminal 4 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the CCSM.
7. Ignition ON, test for 4.8-5.2 V between the signal circuit terminal 5 and ground. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the CCSM. 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 CCSM.
8. Ignition OFF then ON, connect a test lamp between the control circuits listed below and ground. Press the HEAT switch when testing the heat control circuit and the COOL switch when testing the cool control circuit. The test lamp should illuminate or slowly illuminate for approximately 2-4 seconds after the switch is pressed. On the heat control circuit, the test lamp may exhibit a 4 second delay before it starts to illuminate. Seat cushion heat control circuit terminal 1 Seat cushion cool control circuit terminal 3 If the test lamp does not illuminate, test the appropriate control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the CCSM. If the test lamp is always ON, test the appropriate control circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
9. Ignition OFF then ON, connect a test lamp between the circuits listed below and ground. The test lamp should illuminate or slowly illuminate for approximately 5 seconds after pressing the HEAT switch. Seat cushion blower control circuit terminal 2 Seat cushion blower speed control circuit terminal 7 If the test lamp does not illuminate, test the appropriate circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the CCSM. If the test lamp is always ON, test the appropriate circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
10. Ignition OFF, connect the harness connector to the seat cushion ventilation heating and cooling module.
11. Disconnect the harness connector at the seat back ventilation heating and cooling module.
12. Test for less than 5 ohms between the low reference circuit terminal 4 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the CCSM.
13. Ignition ON, test for 4.8-5.2 V between the signal circuit terminal 5 and ground. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the CCSM. 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 CCSM.
14. Ignition OFF then ON, connect a test lamp between the control circuits listed below and ground. Press the HEAT switch when testing the heat control circuit and the COOL switch when testing the cool control circuit. The test lamp should illuminate or slowly illuminate for approximately 4 seconds after the switch is pressed. On the heat control circuit, the test lamp may exhibit a 4 second delay before it starts to illuminate. Seat back heat control circuit terminal 1 Seat back cool control circuit terminal 3 If the test lamp does not illuminate, test the appropriate control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the CCSM. If the test lamp is always ON, test the appropriate control circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
15. Ignition OFF then ON, connect a test lamp between the circuits listed below and ground. The test lamp should illuminate or slowly illuminate for approximately 5 seconds after pressing the HEAT switch. Seat back blower control circuit terminal 2 Seat back blower speed control circuit terminal 7 If the test lamp does not illuminate, test the appropriate circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the CCSM. If the test lamp is always ON, test the appropriate circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
16. If all circuits test normal, test or replace the appropriate seat cushion or seat back ventilation heating and cooling module.

Ventilation Heating and Cooling Module

1. Ignition OFF, disconnect the harness connectors at the seat cushion and seat back ventilation heating and cooling modules.
2. Test for 300 ohms - 18 kohms between the temperature sensor signal circuit terminal 5 and the low reference circuit terminal 8. If not within the specified range, replace the ventilation heating and cooling module.
3. Test for 0.9 - 10 ohms between the heat control circuit terminal 1 and the cool control circuit terminal 3. If not within the specified range, replace the ventilation heating and cooling module.
4. Test for 6 k - 9 kohms between blower control circuit terminal 2 and the low reference circuit terminal 4. If not within the specified range, replace the ventilation heating and cooling module.
5. Test for 290 k - 420 kohms between blower speed control circuit terminal 7 and the low reference circuit terminal 4. If not within the specified range, replace the ventilation heating and cooling module.

Temperature vs Resistance

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver or Passenger Seat Back Ventilation Heating and Cooling Blower Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
2. «Driver or Passenger Seat Cushion Ventilation Heating and Cooling Blower Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
3. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the MSM and CCSM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/escalade/gmt900-2006-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The heat and cool seat functions for the driver and passenger seats are controlled by the climate control seat module (CCSM) that is located under the passenger seat cushion. When a driver or passenger heat or cool seat switch is pressed, a low reference signal is applied through the switch signal circuit to the door lock/window switch. In response to the switch input, the door lock/window switch simultaneously illuminates the appropriate heated/cooled switch indicators and sends a serial data message to the memory seat module (MSM) indicating the heat or cool seat request. The MSM then sends a pulse width modulation (PWM) signal through the appropriate heated/cooled seat mode signal circuit to the CCSM. The CCSM then applies battery positive voltage to the seat cushion and seat back thermal electronic devices (TEDs) and a pre-determined voltage to the blower motors. To determine seat temperature, the CCSM supplies a 5 V signal and a low reference to the temperature sensors that are attached to each TED. The temperature sensors are variable resistors, their resistance changes as the temperature of the seat changes. Then based on the seat temperature, the CCSM controls the voltage level that it applies to the TEDs and blower motors.

The following conditions must be met in order to perform valid tests when diagnosing the climate control seat system

1. The ignition must be cycled OFF then ON between each test in order to reset the CCSM.
2. Most circuit faults will set a DTC within 1.5 minutes. However, some circuit faults may cause a performance problem in one mode and be inoperative and set a DTC in another mode. In some cases it may take 5 minutes or more for a DTC to set. Operate the heated/cooled seat in each of the three modes for 5 minutes or more then check for DTCs.
3. The engine must be running in order to supply the CCSM with the amount of current needed to operate the heated/cool seat system.

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Heated/Cooled Seats Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/escalade/gmt900-2006-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. If both, the driver and passenger heated and cooled seats are inoperative, refer to Driver and Passenger Heated/Cool Seats Inoperative.
2. Ignition ON, observe the scan tool Driver Door Switch parameters listed below while pressing and releasing the appropriate switch. The readings should change between Inactive and Active or Off and ON. Seat Back Heat Mode Sw. Seat Cool Mode Switch Seat Heat Mode Sw. If the reading does not change between Inactive and Active or Off and ON, refer to the Heated and Cooled Seat Switch component test. If the switch tests normal, replace the driver door lock/window switch. If the readings test normal, but the driver heat/cool seat is inoperative, refer to Driver Heated/Cool Seat Circuit System Test
3. Observe the scan tool Passenger Door Switch parameters listed below while pressing and releasing the appropriate switch. The readings should change between Inactive and Active or Off and ON. Seat Back Heat Mode Sw. Seat Cool Mode Switch Seat Heat Mode Sw. If the reading does not change between Inactive and Active or Off and ON, refer to the Heated and Cooled Seat Switch component test. If the switch tests normal, replace the front passenger door lock/window switch. If the readings test normal, but the passenger heat/cool seat is inoperative, refer to Passenger Heated/Cool Seat Circuit System Test
4. If all heated and cooled seat functions operate normal, but the heated/cooled seat switch indicators do not illuminate or are always ON, refer to the Heated and Cooled Seat Switch component test. If the switch tests normal, replace the appropriate door lock/window switch.

Driver and Passenger Heated/Cool Seats Inoperative

1. Ignition OFF, disconnect the X1 harness connector at the CCSM.
2. Verify that a test lamp illuminates between the ground circuit terminal M and B+. If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Verify that a test lamp illuminates between the B+ circuit terminal E and ground. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
4. Disconnect the X2 harness connector at the CCSM.
5. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 1 and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
6. If all circuits test normal, replace the CCSM.

Driver Heated/Cool Seat Circuit System Testing

1. Ignition OFF, disconnect the X3 harness connector at the CCSM.
2. Connect a test lamp between the signal circuit terminal 14 and B+.
3. Ignition ON, press the HEAT or COOL seat switch through the high, medium, and low positions to OFF. The test lamp should illuminate until the OFF position is reached. If the test lamp does not illuminate, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the MSM. If the test lamp remains ON with the switch in the OFF position, test the signal circuit for a short to ground. If the circuit tests normal, replace the MSM.
4. Connect the X3 harness connector at the CCSM.
5. Disconnect the harness connector at the seat cushion ventilation heating and cooling module.
6. Test for less than 5 ohms between the low reference circuit terminal 4 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the CCSM.
7. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal 5 and ground. 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 CCSM. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
8. Ignition OFF then ON, connect a test lamp between the control circuit terminals listed below and ground. Press the HEAT switch when testing the heat control circuit and the COOL switch when testing the cool control circuit. The test lamp should illuminate or slowly illuminate for approximately 2 - 4 seconds after the switch is pressed. On the heat control circuit, the test lamp may exhibit a 4 second delay before it starts to illuminate. Seat cushion heat control circuit terminal 1 Seat cushion cool control circuit terminal 3 If the test lamp does not illuminate, test the appropriate control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the CCSM. If the test lamp is always ON, test the appropriate control circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
9. Ignition OFF then ON, connect a test lamp between the circuit terminals listed below and ground. The test lamp should illuminate or slowly illuminate for approximately 5 seconds after pressing the HEAT switch. Seat cushion blower control circuit terminal 2 Seat cushion blower speed control circuit terminal 7 If the test lamp does not illuminate, test the appropriate circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the CCSM. If the test lamp is always ON, test the appropriate circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
10. Ignition OFF, connect the harness connector to the seat cushion ventilation heating and cooling module.
11. Disconnect the harness connector at the seat back ventilation heating and cooling module.
12. Test for less than 5 ohms between the low reference circuit terminal 4 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the CCSM.
13. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal 5 and ground. 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 CCSM. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
14. Ignition OFF then ON, connect a test lamp between the control circuit terminals listed below and ground. Press the HEAT switch when testing the heat control circuit and the COOL switch when testing the cool control circuit. The test lamp should illuminate or slowly illuminate for approximately 4 seconds after the switch is pressed. On the heat control circuit, the test lamp may exhibit a 4 second delay before it starts to illuminate. Seat back heat control circuit terminal 1 Seat back cool control circuit terminal 3 If the test lamp does not illuminate, test the appropriate control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the CCSM. If the test lamp is always ON, test the appropriate control circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
15. Ignition OFF then ON, connect a test lamp between the circuit terminals listed below and ground. The test lamp should illuminate or slowly illuminate for approximately 5 seconds after pressing the HEAT switch. Seat back blower control circuit terminal 2 Seat cushion blower speed control circuit terminal 7 If the test lamp does not illuminate, test the appropriate control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the CCSM. If the test lamp is always ON, test the appropriate control circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
16. If all circuits test normal, test or replace the appropriate seat cushion or seat back ventilation heating and cooling module.

Passenger Heated/Cool Seat Circuit System Testing

1. Ignition OFF, disconnect the X3 harness connector at the CCSM.
2. Connect a test lamp between the signal circuit terminal 6 and B+.
3. Ignition ON, press the HEAT or COOL seat switch through the high, medium, and low positions to OFF. The test lamp should illuminate until the OFF position is reached. If the test lamp does not illuminate, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the MSM. If the test lamp remains ON with the switch in the OFF position, test the signal circuit for a short to ground. If the circuit tests normal, replace the MSM.
4. Connect the X3 harness connector at the CCSM.
5. Disconnect the harness connector at the seat cushion ventilation heating and cooling module.
6. Test for less than 5 ohms between the low reference circuit terminal 4 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the CCSM.
7. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal 5 and ground. 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 CCSM. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
8. Ignition OFF then ON, connect a test lamp between the control circuit terminals listed below and ground. Press the HEAT switch when testing the heat control circuit and the COOL switch when testing the cool control circuit. The test lamp should illuminate or slowly illuminate for approximately 2 - 4 seconds after the switch is pressed. On the heat control circuit, the test lamp may exhibit a 4 second delay before it starts to illuminate. Seat cushion heat control circuit terminal 1 Seat cushion cool control circuit terminal 3 If the test lamp does not illuminate, test the appropriate control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the CCSM. If the test lamp is always ON, test the appropriate control circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
9. Ignition OFF then ON, connect a test lamp between the circuit terminals listed below and ground. The test lamp should illuminate or slowly illuminate for approximately 5 seconds after pressing the HEAT switch. Seat cushion blower control circuit terminal 2 Seat cushion blower speed control circuit terminal 7 If the test lamp does not illuminate, test the appropriate circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the CCSM. If the test lamp is always ON, test the appropriate circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
10. Ignition OFF, connect the harness connector to the seat cushion ventilation heating and cooling module.
11. Disconnect the harness connector at the seat back ventilation heating and cooling module.
12. Test for less than 5 ohms between the low reference circuit terminal 4 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the CCSM.
13. Ignition ON, test for 4.8 - 5.2 V between the signal circuit terminal 5 and ground. 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 CCSM. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
14. Ignition OFF then ON, connect a test lamp between the control circuit terminals listed below and ground. Press the HEAT switch when testing the heat control circuit and the COOL switch when testing the cool control circuit. The test lamp should illuminate or slowly illuminate for approximately 4 seconds after the switch is pressed. On the heat control circuit, the test lamp may exhibit a 4 second delay before it starts to illuminate. Seat back heat control circuit terminal 1 Seat back cool control circuit terminal 3 If the test lamp does not illuminate, test the appropriate control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the CCSM. If the test lamp is always ON, test the appropriate control circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
15. Ignition OFF then ON, connect a test lamp between the circuit terminals listed below and ground. The test lamp should illuminate or slowly illuminate for approximately 5 seconds after pressing the HEAT switch. Seat back blower control circuit terminal 2 Seat back blower speed control circuit terminal 7 If the test lamp does not illuminate, test the appropriate control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the CCSM. If the test lamp is always ON, test the appropriate circuit for a short to voltage. If the circuit tests normal, replace the CCSM.
16. If all circuits test normal, test or replace the appropriate seat cushion or seat back ventilation heating and cooling module.

Heated and Cooled Seat Switch

1. Ignition OFF, disconnect the X4 harness connector at the appropriate door lock/window switch.
2. Test for infinite resistance between the low reference circuit terminal 4 and the signal terminals listed below the with the switch in the open position. Seat back only mode switch terminal 7 Seat back cushion heat switch terminal 6 Seat cool switch terminal 3 If not the specified value, replace the heated and cooled seat switch.
3. Test for less than 2 ohms between the low reference circuit terminal 4 and the signal terminals listed below with the appropriate switch in the closed position. Seat back only mode switch terminal 7 Seat back cushion heat switch terminal 6 Seat cool switch terminal 3 If greater than the specified range, replace the heated and cooled seat switch.
4. Connect a 3 A fused jumper wire between the low reference circuit terminal 4 and ground.
5. Connect a test lamp between B+ and each control terminal listed below. The appropriate indicator should illuminate. Seat back only mode indicator terminal 11 Seat cool mode indicator terminal 12 Seat back and cushion indicator terminal 10 Low temperature indicator terminal 9 Medium temperature indicator terminal 1 High temperature indicator terminal 2 If any indicator does not illuminate, replace the heated and cooled seat switch.

Ventilation Heating and Cooling Module

1. Ignition OFF, disconnect the harness connectors at the seat cushion and seat back ventilation heating and cooling modules.
2. Test for 300 ohms - 18 kohms between the temperature sensor signal circuit terminal 5 and the low reference circuit terminal 8. If not within the specified range, replace the ventilation heating and cooling module.
3. Test for 0.9 - 10 ohms between the heat control circuit terminal 1 and the cool control circuit terminal 3. If not within the specified range, replace the ventilation heating and cooling module.
4. Test for 6 k - 9 kohms between blower control circuit terminal 2 and the low reference circuit terminal 4. If not within the specified range, replace the ventilation heating and cooling module.
5. Test for 290 k - 420 kohms between blower speed control circuit terminal 7 and the low reference circuit terminal 4. If not within the specified range, replace the ventilation heating and cooling module.

Temperature vs Resistance

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Driver or Passenger Seat Back Ventilation Heating and Cooling Blower Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
2. «Driver or Passenger Seat Cushion Ventilation Heating and Cooling Blower Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/seats/#seat-heating-system-seat-cooling-system)
3. «Control Module References»(/cadillac/escalade/gmt900-2006-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for the MSM and CCSM replacement, setup, and programming

Removal Procedure

1. Remove door upper trim panel. Refer to «Upper Extension Trim Panel Replacement (Escalade)»(/cadillac/escalade/gmt900-2006-2014/remont/exteriorinterior-trim/#interior-trim-system-and-paneling) or «Upper Extension Trim Panel Replacement (Except Escalade)»(/cadillac/escalade/gmt900-2006-2014/remont/exteriorinterior-trim/#interior-trim-system-and-paneling) .
2. Pull the door trim panel away from the door and support the bottom of the trim panel on the door panel hooks. Refer to «Front Side Door Trim Panel Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/exteriorinterior-trim/#interior-trim-system-and-paneling) .
3. Disconnect the electrical connector.
4. Remove the front side door heater switch fasteners (1).
5. Remove the front side door heater switch assembly (2).

Installation Procedure

1. Install the front side door heater switch assembly (2).
2. Install the front side door heater switch fasteners and tighten to 2 N.m (18 lb in).
3. Connect the electrical connector.
4. Install the door trim panel. Refer to «Front Side Door Trim Panel Replacement»(/cadillac/escalade/gmt900-2006-2014/remont/exteriorinterior-trim/#interior-trim-system-and-paneling) .

Scheme 111

Scheme 112

Scheme 113

Driver or Passenger Seat Back Cushion Heater Replacement (without HP2)

Scheme 114

Scheme 115

Scheme 116

Scheme 117

Scheme 118

Scheme 119

Scheme 120

Scheme 121

Driver Seat Cushion Ventilation Heating and Cooling Module Replacement

Scheme 122

Description

The driver and passenger heated seats have 2 heat zone operating modes with 3 heat level modes and will operate only while the engine is running. The heat zones are determined by which of the 2 heated seat buttons are pressed, while the heat level is determined by the number of times they are pressed. Pressing the seat cushion button 1 time will activate the seat back and cushion heater elements in the high mode. Each time the seat cushion button is pressed the seat back and cushion heat level is reduced from high to medium, low, and off. Pressing the heated seat back button 1 time will activate only the seat back heater element in the high mode. Each time the seat back button is pressed the seat back heat level is reduced from high to medium, low, and off. During heated seat operation the heat zone operating mode may be changed without affecting the current heat level mode. During a cold ambient remote start activation the heated seats will turn on.

Cadillac Switches

The heated seat switches are an integrated to the HVAC control head and when a heated seat switch is pressed the active switch signal is sent to the memory seat module as a GMLAN message. The memory seat module determines the heated seat mode based on the switch messages and sends a message to the HVAC control head to display the heated seat indicators as necessary.

Chevrolet and GMC Switches

The heated seat switches are momentary contact switches and are inputs to the driver and passenger door lock/window switches. A ground circuit is connected to the switch assembly through the door lock/window switch, and when a heated seat switch is pressed and released a brief switch signal is supplied to the door lock/window switch. Whenever the door module receives an active heated seat switch input, the active switch signal is sent to the memory seat module as a GMLAN message. The memory seat module determines the heated seat mode based on the switch messages and sends a message to the door lock/window switch to display the heated seat indicators as necessary.

Heated Seat Operation

The memory seat module controls the voltage supply and the ground circuits to the seat heater elements. When a heated seat function is commanded active, the seat module will switch battery voltage to the heater element supply circuits, and ground is provided through pulse width modulation (PWM) low side drive control circuits. During heated seat operation both the seat back and cushion heater elements are supplied battery voltage. The seat module grounds the appropriate control circuits for back only or back and cushion heating modes, and opens or closes the active control circuits as necessary in order to maintain the desired seat temperature. The seat module relies on 4 independent inputs from thermistors located in the seat back and seat cushion of the driver and passenger seats to control heated seat temperatures. The thermistors are 2-wire sensors supplied with a 5-volt referenced signal circuit and a low reference circuit from the seat module. Resistance through the thermistors varies with temperature causing the heated seat sensor signal circuit voltage levels to decrease as the seat back temperatures rise. The seat modules allow heated seat operation only while the engine is running which is determined by a GMLAN serial data circuit message.

Heated Seats Description and Operation (KA6)

The rear passenger heated seats have cushion heat only with 2 heat level modes and will operate only while the engine is running. The left or right cushion is selected by pressing one of the 2 heated seat buttons, while the heat level is determined by the number of times they are pressed. Pressing the seat heat button 1 time will activate the cushion heater elements in the high mode. Each time the seat cushion button is pressed the seat cushion heat level is reduced from high to low, and off.

The heated seat switches are momentary contact switches and are inputs to the rear seat audio module. A ground circuit is connected to the switch assembly through the rear seat audio module. Whenever the rear seat audio module receives an active heated seat switch input, the next heated seat operating mode is determined by whatever the current mode may be. The seat heater elements are controlled by the rear heated seat module using inputs from the rear seat audio through GMLAN serial data circuit messages. The rear heated seat module controls the voltage supply and the ground circuits to the seat heater elements. When a heated seat function is commanded active, the seat module will switch battery voltage to the heater element supply circuits, and ground is provided through low side drive control circuits. During heated seat operation the seat cushion heater elements are supplied battery voltage. The seat module grounds the appropriate control circuits for left or right cushion heating modes, and opens or closes the active control circuits as necessary in order to maintain the desired seat temperature. The seat module relies on 2 independent inputs from thermistors located in the seat cushion of the left and right seats to control heated seat temperatures. The thermistors are 2-wire sensors supplied with a 5-volt referenced signal circuit and a low reference circuit from the seat module. Resistance through the thermistors varies with temperature causing the heated seat sensor signal circuit voltage levels to decrease as the seat back temperatures rise. The seat module allows heated seat operation only while the engine is running which is determined by a GMLAN serial data circuit message.

Heated/Cooled Seats Description and Operation

The driver and front passenger heated cooled seat system consist of the following components

1. Seat cushion heated/cool ventilation module
2. Seat back heated/cool ventilation module
3. Memory seat module
4. Climate Control Seat Module
5. Heated/cooled seat switches and HVAC control module (Escalade)
6. Heated/cooled seat switch and door lock/window switch (Chevrolet and GMC)

Air Circulation

When the heated/cool seat switch is pressed to initiate operation of the climate control seat system, cabin air is drawn through the heated/cool ventilation module air filter, then directed through passages in the foam of the seat cushion and seat back to the seat's occupant. In order for the climate control seat system to operate to its optimum performance, it is crucial to have unrestricted air flow through the system. A dirty or restricted air filter, the blockage of an exhaust air duct, a misaligned heated/cool ventilation module, or incorrect foam installation of the seat cushion or seat back will all have negative effects on climate control seat system operation.

Seat Heat/Cool Ventilation Module

Each heated/cool seat has 2 heat/cool ventilation modules, one located under the seat cushion and one located in the seat back. These modules are controlled by the CCSM. Each ventilation module contains a thermo-electric device (TED), a temperature sensor, and a blower motor. The TED and temperature sensor are mounted downstream of the blower motor. Each TED consists of a circuit of positive and negative connections sandwiched between 2 ceramic plates. Each ceramic plate is equipped with copper fins for heat exchange. The air flowing past these fins is either directed as conditioned air into the seat cushion and seat back, or directed into the cabin as waste air.

A TED is essentially a solid state heat pump that is used to heat or cool the air supply to the seat cushion and seat back. When voltage is applied to a TED, one side releases energy as heat, while the opposite side absorbs energy and gets cold. When the polarity of the current flow to the TEDs is switched, the hot and cool sides of the TED reverse.

During the following climate control seat system description and operation, the TEDs, blower motors, and temperature sensors will be referenced independently even though they are all packaged together as a module.

Climate Control Seat System

The climate control seat system consists of 2 heated/cool ventilation modules and one CCSM that controls both the driver and passenger heated/cool seats systems. The CCSM is mounted below the front passenger seat cushion.

Once a climate control seat system is activated, cabin air is drawn through the seat blower motors and directed across the fins of each of the TED located under the seat cushion and in the seat back. The air is either heated or cooled as it passes over the TEDs. This conditioned air is then directed through channels in the foam of the seat pad and through small holes in the seat cover to the occupant. Once the system is activated, the CCSM uses a set of algorithms to control the temperature of the selected heating or cooling modes.

Climate Control Seat Module Power and Ground

Battery positive voltage is supplied at all times to the CCSM through the battery positive voltage circuit and a 30 A fuse that is located in the I/P fuse block. This voltage is used by the CCSM to supply power to the TEDs and the blower motors. Ignition voltage is also supplied to the CCSM through the ignition voltage circuit and a 10 A fuse located in the underhood fuse block. The ignition voltage is used to power up the CCSM and allows the climate control seat system to operate only with the ignition in the ON position. The CCSM is grounded through the module ground circuit and G304.

Climate Control Seat Module

The CCSM is located under the passenger seat and controls 4 individual driver and passenger seat heat/cool ventilation blowers. When the CCSM receives a heated cooled seat command through the left or right heated/cooled seat mode signal circuit, the appropriate seat heat/cool ventilation blowers will be operated by the CCSM.

Memory Seat Module

The memory seat module (MSM) monitors the heated cooled seat switches through serial data message inputs and determines the heated cooled seat operating modes and temperature levels. The MSM controls the operating mode of the CCSM through 2 pulse width modulation (PWM) signal circuits. The left and right heated/cooled seat mode signal circuits are referenced from battery voltage by the CCSM and pulsed low by the MSM. Each heated cooled seat is capable of operating in 3 modes with 3 temperature levels so the MSM uses 9 PWM frequencies for each signal circuit to command the heated cooled seat modes to the CCSM.

Modes of Operation

There are 3 modes available for climate control seat system operation, heated seat, cool seat, and back only heat operation. When a heat or cool seat mode signal request is received, the CCSM will activate both the seat cushion and seat back ventilation modules. When the seat BACK ONLY mode button is pressed once, the CCSM will deactivate the seat cushion ventilation module and leave the seat back ventilation module ON. Press the BACK ONLY mode button a second time and the CCSM will re-activate the seat cushion ventilation module.

Heated/Cooled Seat Switches and HVAC Control Module (Escalade)

The heated and cooled seat system is controlled through 3 different switch inputs of the HVAC control module. When one of the switches is pressed, the HVAC control module sends a serial data message to the MSM indicating the switch input. In response to this message, the MSM sends a pulse width modulation (PWM) signal through the heated/cool seat mode signal circuit to the CCSM indicating the heated or cooled seat request. During heated or cooled seat operation the HVAC control module displays the switch symbol of the active operating mode and the temperature level bars on the climate control display determined by a serial data message from the MSM.

Heated/Cooled Seat Switch and Door Lock/Window Switch (Chevrolet and GMC)

The heated and cooled seat system is controlled through the heated and cooled seat switches that are located on the door panels. Ground is supplied to the heated/cool seat switch through the low reference circuit and the respective door module. The door module plays an important part of the climate control seat operation, first by relaying the selected switch inputs to the MSM, and second, by controlling the mode and temperature indicators of the heated/cool seat switch.

When either a heat or cool seat switch is pressed, ground is applied through the switch contacts and the switch signal circuit to the door lock/window switch. In response to this signal, the door lock/window switch sends a serial data message to the MSM indicating the switch input. In response to this message, the MSM then sends a pulse width modulation (PWM) signal through the appropriate heated/cool seat mode signal circuit to the CCSM indicating the heated or cooled seat request. The door lock/window switch then applies a ground through the appropriate heat or cool seat indicator control circuit to the switch illuminating the selected heat or cool mode indicator. At the same time, the door lock/window switch also applies a ground through the appropriate high, medium, or low temperature indicator control circuits illuminating temperature mode indicators.

Temperature Sensors

As mentioned above in the heated/cool ventilation module description, the seat cushion and seat back temperature sensors are each packaged with a TED and blower motor as an assembly. The seat temperature sensors are thermistors which are attached directly to the fins of each TED. The CCSM supplies a 5 V reference voltage through the temperature sensor signal circuit and ground through the temperature sensor low reference circuit to the respective seat cushion and seat back temperature sensors. As the temperature of the TED changes, the resistance of the thermistor varies changing the feedback voltage of the temperature sensor signal circuit. This voltage varies from 0.5 - 4 V. The CCSM monitors this voltage signal to determine the fin temperature so that it can adjust and maintain the seat temperature to the selected switch input.

Blower Motors

Also, as mentioned above in the heated/cool ventilation module description, the seat cushion and seat back blower motors are each packaged with a TED and temperature sensor as an assembly. Each blower motor contains logic that will allow for the blower to operate only when the ignition is in the ON position. When the ignition is ON and the CCSM is powered up, the module supplies battery positive voltage through the blower supply voltage circuit to the logic of the blower motors. When the heated/cool seat switch is pressed, the CCSM applies a pre-determined voltage through the blower speed control circuits to the blower motors. The module also supplies each blower motor with a ground path through the blower low reference circuits.

With the climate control seat system, the speed of the blower motor is not related directly to the High, Med, or Low input from the heated/cool seat switch. The speed of the blower motor is related directly to TED temperature as described below in heated and cooled seat operation.

When the heated seat switch is pressed for High Heat, the CCSM will transition to the HEAT state. In the heat state, the CCSM applies a pre-determined voltage through the ventilation module heat control circuits to the heat side of the TEDs, while providing a ground through the ventilation module cool control circuit to the cool side of the TEDs. A pre-determined voltage is also applied to the blower motors. The CCSM uses the following sequence beginning with the Heat SoftStart Mode to achieve the set point temperature before it can enter the Control Heat Mode. If the seat temperature is already above the Temperature Set Point, the CCSM will skip the Heat SoftStart Mode and proceed to the Control Heat Mode.

1. Heat SoftStart Mode-While in transition to the heat mode, the CCSM will initiate the SoftStart Mode. The intent of the Heat SoftStart Mode is for the module to bring the ventilation module fin temperature up to the pre-determined Temperature Set Point of the Max Heat Mode. The module does this by setting the blower motor speed control to a pre-determined voltage while ramping up the ventilation module voltage from 0 volts to the maximum voltage, not to exceed 5 seconds, at which point the system transitions to Max Heat Mode. The Heat SoftStart Mode will only be attempted once per ignition cycle.
2. Max Heat Mode-Upon completion of the Heat SoftStart Mode, the CCSM will initiate Max Heat Mode. The intent of the MAX Heat Mode is to maintain the fin temperature to the pre-determined Temperature Set Point in order for the CCSM to go into the Control Heat Mode. The CCSM does this by maintaining the TED at the maximum voltage while maintaining the minimum required airflow across the fins. After max heat duration has been reached, or upon achieving the pre-determined Temperature Set Point, the system transitions to the Control Heat Mode.
3. Control Heat Mode-At the completion of Max Heat Mode, the CCSM will initiate Control Heat Mode. The intent of the Control Heat Mode is to maintain the desired fin temperature or the set point temperature. The CCSM does this in two ways; first by adjusting the voltage supply to the blower motor to control blower motor speed, then secondly by controlling the voltage supplied to the TED. The CCSM updates these voltages once every second. Increasing the blower motor speed will decrease the fin temperature. If the maximum blower motor speed is achieved and the fin temperature is still above the set point of high heat, the CCSM will then begin to control the TED voltage to achieve Temperature Set Point. Decreasing the TED voltage decreases the fin temperature. If the CCSM is trying to raise the fin temperature to set point by using TED voltage, and the fin temperature cannot be raised because the TED voltage is at the maximum, the CCSM reduces the blower motor speed to achieve the Temperature Set Point.

Cooled Seat Operation

When the cool seat switch is pressed for High Cool, the CCSM will transition to the COOL state. In response to this command, the CCSM applies a pre-determined voltage through the ventilation module cool control circuits to the cool side of the TEDs while providing a ground through the ventilation module heat control circuits to the heat side of the TEDs. A pre-determined voltage is also applied to the blower motors. The CCSM uses the following sequence, beginning with the Cool SoftStart Mode, to achieve the set point temperature before it can enter the Open Loop Cool Mode.

1. Cool SoftStart Mode-The intent of the Cool SoftStart Mode is for the CCSM to bring the TED fin temperature to maximum cool temperate. The CCSM does this by setting the blower motor speed control voltage to 0 volts, while ramping up the TED voltage duty cycle from 0 volts to maximum voltage duty cycle over a period not to exceed 5 seconds. Then, with the TEDs at maximum voltage, the CCSM will increase the blower speed to maximum voltage, and keep these settings for the MAX COOL DURATION. After which the system transitions to the Open Loop Cool Mode.
2. Open Loop Cool Mode-At the completion of Cool SoftStart Mode, the CCSM will initiate Open Loop Cool Mode. The intent of this mode is to maintain the set point fin temperature based on the input of the cool seat switch. First, by controlling the speed of the blower motor, then secondly, by controlling TED voltage. The CCSM updates these voltages once every second.

Fault State

The climate control seat system will operate normally in the battery voltage range of 9-16 volts. If the system voltage falls outside of this voltage range, the module will shut down all outputs until the system returns to its normal operating voltage range. The system will also transition to the fault state per the conditions listed below, by shutting down all outputs for the seat in which the fault occurred.

High Temperature Fault State

During the heating or cooling modes, if the TED temperatures listed below are exceeded for more than 4 seconds, the system will enter the High Temperature Fault State. At which time the CCSM will set the TED voltage duty cycle to 0%, set the blower speed control to maximum voltage to blow ambient air over the TEDs, attempting to reduce the TED temperature below the listed maximums. The system will operate in this mode for 30 seconds. If the over temperature fault still exists after 30 seconds, the system will transition to the FAULT state for the remainder of the ignition cycle. If the over temperature fault clears, the system will then transition to the appropriate heat or cool softstart mode. The following temperatures are based upon individual readings of either sensor

1. Heat mode TED temperature exceeds 230°F (110°C).
2. Cool mode TED temperature exceeds 149°F (65°C).

Temperature Delta Fault

During the heating or cooling modes, if the CCSM detects a temperature difference between the seat cushion and seat back TED temperature sensors exceeding the delta temperature listed below for more than 4 seconds, the system will enter the Temperature Delta Fault state. At which time the CCSM will set the TED voltage duty cycle to 0%, set the blower speed control to maximum voltage to blow ambient air over the TEDs, attempting to reduce the delta temperature to less than 68°F. The system will operate in this mode for 30 seconds. If the delta temperature fault still exists after 30 seconds, the system will transition to the FAULT state and remain there until the ignition has been set to OFF.

1. Delta between the seat cushion and seat back temperature sensors is 104°F (40°C).
2. This fault state is disabled in the back only mode.

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Component Connector End Views
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Control Module References
• Diagnostic Repair Verification
• Checking Aftermarket Accessories
• Upper Extension Trim Panel Replacement (Escalade)
• Fastener Caution
• Front Seat Replacement - Bucket (with HP2)
• Front Seat Adjuster Replacement (with HP2)
• DTC B1925 or B2170 (w/o HP2 with Memory)
• Heated Seats Description and Operation (KA6)
• Driver or Passenger Seat Back Cushion Heater Replacement (without HP2)
• Heated/Cooled Seats Description and Operation