Part 2
Seating
Pinpoint Test AW: DTC B2729
Refer to Wiring Diagram Set 119, Climate Controlled Seats for schematic and connector information. Diagrams By Number
Normal Operation
The Dual Climate Controlled Seat Module (DCSM) monitors the temperature sensor. If the temperature exceeds the specified limits, the DTC will be set.
- DTC B2729 (Cushion Over-Temp Detected)- In the heating mode, if the driver seat cushion Thermo-Electric Device (TED) temperature exceeds 85°C (185°F) for more than 34 seconds, the TED (Thermo-Electric Device) is disconnected or the duct is blocked, the DCSM (Dual Climate Controlled Seat Module) will shut down the driver seat system and set this DTC.
- DTC B2729 (Cushion Over-Temp Detected)- In the cooling mode, if the driver seat cushion TED (Thermo-Electric Device) temperature exceeds 70°C (158°F) for more than 34 seconds, the TED (Thermo-Electric Device) is disconnected or the duct is blocked, the DCSM (Dual Climate Controlled Seat Module) will shut down the driver seat system and set this DTC.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Restricted cushion TED (Thermo-Electric Device) filter
- Crushed or restricted climate controlled seat manifold
- Cushion TED (Thermo-Electric Device) assembly
- Dual Climate Controlled Seat Module (DCSM)
PINPOINT TEST AW : DTC B2729
NOTICE: When taking measurements at Dual Climate Controlled Seat Module (DCSM) harness connectors, do not insert the electrical probes into the female connector pins. Inserting the probes into connector pins can cause intermittent or open electrical connections after reassembly resulting in Diagnostic Trouble Codes (DTCs) and system failure. Touching the tip of these connector pins is recommended instead.
NOTE: The air bag warning indicator illuminates when the correct Restraints Control Module (RCM) fuse is removed and the ignition is ON.
NOTE: The Supplemental Restraint System (SRS) must be fully operational and free of faults before releasing the vehicle to the customer.
AW12 CHECK THE DRIVER SEAT CUSHION BLOWER CIRCUITS FOR AN OPEN
- Measure the resistance between:
- DCSM (Dual Climate Controlled Seat Module) C3265C-16, circuit CHS03 (GN/BN), harness side and driver seat cushion TED (Thermo-Electric Device) C3035-2, circuit CHS03 (GN/BN), harness side.
- DCSM (Dual Climate Controlled Seat Module) C3265C-15, circuit RHS03 (GY/OG), harness side and driver seat cushion TED (Thermo-Electric Device) C3035-4, circuit RHS03 (GY/OG), harness side.
Are the resistances less than 5 ohms?
Yes
GO to AW13.
No
REPAIR the circuit(s). CLEAR the DTCs. REPEAT the self-test.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C3051 and passenger seat side air bag module C339.
CONNECT driver seat safety belt buckle pretensioner C3065 and passenger seat safety belt buckle pretensioner C3066.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
AW13 CHECK THE DRIVER SEAT CUSHION BLOWER RESISTANCE
- NOTICE: The ohmmeter must be connected with the positive lead to pin 2 and the negative lead to pin 4 when measuring. Ohmmeter leads incorrectly connected results in false readings and leads to incorrect identification of components that are not damaged.
Measure the resistance between driver seat cushion TED (Thermo-Electric Device) C3035 pin 2 and pin 4, component side.
Is the resistance between 4,000 ohms and 10,000 ohms?
Yes
GO to AW14.
No
INSTALL a new driver seat cushion TED (Thermo-Electric Device). REFER to Seat Cushion Thermo-Electric Device . CLEAR the DTCs. REPEAT the self-test.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C3051 and passenger seat side air bag module C339.
CONNECT driver seat safety belt buckle pretensioner C3065 and passenger seat safety belt buckle pretensioner C3066.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
AW14 CHECK THE DRIVER SEAT CUSHION BLOWER SPEED CONTROL RESISTANCE
- NOTICE: The ohmmeter must be connected with the positive lead to pin 7 and the negative lead to pin 4 when measuring. Ohmmeter leads incorrectly connected results in false readings and leads to incorrect identification of components that are not damaged.
Measure the resistance between driver seat cushion TED (Thermo-Electric Device) C3035 pin 7 and pin 4, component side.
Is the resistance between 240K ohms and 400K ohms?
Yes
GO to AW15.
No
INSTALL a new driver seat cushion TED (Thermo-Electric Device). REFER to Seat Cushion Thermo-Electric Device . CLEAR the DTCs. REPEAT the self-test.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C3051 and passenger seat side air bag module C339.
CONNECT driver seat safety belt buckle pretensioner C3065 and passenger seat safety belt buckle pretensioner C3066.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
AW15 CHECK THE DRIVER SEAT CUSHION TED (Thermo-Electric Device) INSTALLATION AND FOR CRUSHED SEAT CUSHION
- Ignition OFF.
- Remove the driver seat. Refer to Seat- Front .
- Remove the driver seat cushion cover. Refer to Seat Cushion Cover- Front .
- Inspect the driver seat cushion for the following:
- Is the driver seat cushion TED (Thermo-Electric Device) correctly installed?
- Is the driver seat cushion seat cushion foam pad crushed or restricted?
- Is the driver seat cushion climate controlled seat manifold crushed or restricted?
Is the driver seat cushion TED (Thermo-Electric Device) correctly installed and are there no signs of damage to the foam pad and manifold?
Yes
INSTALL the driver seat cushion cover and seat and GO to AW18.
No
CORRECTLY install the driver seat cushion TED (Thermo-Electric Device) or INSTALL a new driver seat cushion foam pad and/or climate controlled seat manifold. CONNECT the battery ground cable. CLEAR the DTCs. REPEAT the self-test.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C3051 and passenger seat side air bag module C339.
CONNECT driver seat safety belt buckle pretensioner C3065 and passenger seat safety belt buckle pretensioner C3066.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
AW16 CHECK THE DRIVER SEAT CUSHION TED (Thermo-Electric Device) THERMISTOR AND WIRING
- Ignition OFF.
- Depower the SRS (Supplemental Restraint System). Refer to Supplemental Restraint System (SRS) Depowering and Repowering in the General Procedures portion of Restraints and Safety Systems &/or Air Bag Systems.
- Disconnect: Driver Seat Side Air Bag C3051 and Passenger Seat Side Air Bag C339.
- Disconnect: Driver Seat Safety Belt Buckle Pretensioner C3065 and Passenger Seat Safety Belt Buckle Pretensioner C3066.
- Disconnect: DCSM (Dual Climate Controlled Seat Module) C3265B.
- WARNING: Make sure no one is in the vehicle and there is nothing blocking or placed in front of any air bag module when the battery is connected. Failure to follow these instructions may result in serious personal injury in the event of an accidental deployment.
Connect the battery ground cable.
- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3265B-7, circuit VHS26 (VT), harness side and C3035B-8 circuit RHS05 (YE/VT), harness side. Note the ambient temperature and refer to the following table.
Is the resistance within the limits indicated?
Yes
GO to AW18.
No
GO to AW17.
AW17 CHECK THE DRIVER SEAT CUSHION TED (Thermo-Electric Device) THERMISTOR
- Measure the resistance between driver seat cushion TED (Thermo-Electric Device) C3035 pin 5 and pin 8, component side. Note the ambient temperature and refer to the following table.
Is the resistance within the limits indicated?
Yes
REPAIR circuit VHS26 (VT) or RHS05 (YE/VT) for an open or high resistance. CLEAR the DTCs. REPEAT the self-test.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C3051 and passenger seat side air bag module C339.
CONNECT driver seat safety belt buckle pretensioner C3065 and passenger seat safety belt buckle pretensioner C3066.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
No
INSTALL a new TED (Thermo-Electric Device). REFER to Seat Cushion Thermo-Electric Device . CLEAR the DTCs. REPEAT the self-test.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C3051 and passenger seat side air bag module C339.
CONNECT driver seat safety belt buckle pretensioner C3065 and passenger seat safety belt buckle pretensioner C3066.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
AW18 CHECK THE DRIVER SEAT CUSHION TED (Thermo-Electric Device) HEATING/COOLING CIRCUITRY CURRENT DRAW
- Connect: All DCSM (Dual Climate Controlled Seat Module), TED (Thermo-Electric Device) and body harness-to-seat harness connectors.
- NOTICE: It may be necessary to open the seat wire harness conduit to allow placing the inductive current probe around the circuit as described in the following step. Care must be taken when opening up the wire harness so as not to damage any wiring or connectors. Do not damage any wiring or induce stress on any wiring or connectors. Close up the wire harness once repairs to the seat are complete.
NOTE: Use a commercially available inductive current probe (such as Electronic Specialties Current Probe/Multimeter 685 or a Fluke I410 [used with a digital multimeter]) or the low current probe from the Vehicle Measurement Module available for use with Integrated Diagnostic System (IDS). If these are unavailable, the inductive current probe feature from a battery tester may be substituted.
Place an inductive current probe around circuit CHS02 (YE/BU) near DCSM (Dual Climate Controlled Seat Module) C3305A-G and monitor the current draw.
- Start the vehicle and set the driver seat to HIGH heat.
Is the current draw less than 11 amps?
Yes
GO to AW19.
No
INSTALL a new driver seat cushion TED (Thermo-Electric Device). REFER to Seat Cushion Thermo-Electric Device . CLEAR the DTCs. REPEAT the self-test.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C3051 and passenger seat side air bag module C339.
CONNECT driver seat safety belt buckle pretensioner C3065 and passenger seat safety belt buckle pretensioner C3066.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
AW19 CHECK RESISTANCE OF THE DRIVER SEAT CUSHION TED (Thermo-Electric Device) AND WIRING
- Ignition OFF.
- Disconnect: DCSM (Dual Climate Controlled Seat Module) C3265A.
- Measure the resistance between DCSM (Dual Climate Controlled Seat Module) C3265A-G circuit CHS02 (YE/BU), harness side and C3265A-H, circuit RHS02 (BU/OG), harness side.
Is the resistance between 0.9 and 10 ohms?
Yes
GO to AW21.
No
GO to AW20.
AW20 CHECK THE RESISTANCE OF THE DRIVER SEAT CUSHION TED (Thermo-Electric Device)
- Disconnect: Driver Seat Cushion TED (Thermo-Electric Device) C3035.
- Measure the resistance between driver seat cushion TED (Thermo-Electric Device) C3035 pin 1 and pin 3, component side.
Is the resistance between 0.9 and 10 ohms?
Yes
REPAIR circuit CHS02 (YE/BU) or RHS02 (BU/OG) for an open or high resistance. CLEAR the DTCs. REPEAT the self-test.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C3051 and passenger seat side air bag module C339.
CONNECT driver seat safety belt buckle pretensioner C3065 and passenger seat safety belt buckle pretensioner C3066.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
No
INSTALL a new driver seat cushion TED (Thermo-Electric Device). REFER to Seat Cushion Thermo-Electric Device . CLEAR the DTCs. REPEAT the self-test.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C3051 and passenger seat side air bag module C339.
CONNECT driver seat safety belt buckle pretensioner C3065 and passenger seat safety belt buckle pretensioner C3066.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
AW21 CHECK FOR CORRECT DCSM (Dual Climate Controlled Seat Module) OPERATION
- Inspect the DCSM (Dual Climate Controlled Seat Module) and driver seat cushion TED (Thermo-Electric Device) harness and component side connectors and the body harness-to-seat harness connectors for:
- corrosion
- damaged pins
- pushed-out pins
- Connect: All DCSM (Dual Climate Controlled Seat Module), TED (Thermo-Electric Device) and Body Harness-to-Seat Harness Connectors.
- Make sure the connectors are seated correctly.
- Start the engine.
- Set the driver seat to OFF.
- Enter the following diagnostic mode on the scan tool: Clear DTCs - DCSM (Dual Climate Controlled Seat Module).
- Attempt to recreate the fault. With the engine still running set the driver seat to HIGH heat for at least 15 minutes.
Is the concern still present?
Yes
INSTALL a new DCSM (Dual Climate Controlled Seat Module). REFER to Dual Climate Controlled Seat Module (DCSM) . REPEAT the self-test. TEST the system for normal operation.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C3051 and passenger seat side air bag module C339.
CONNECT driver seat safety belt buckle pretensioner C3065 and passenger seat safety belt buckle pretensioner C3066.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C3051 and passenger seat side air bag module C339.
CONNECT driver seat safety belt buckle pretensioner C3065 and passenger seat safety belt buckle pretensioner C3066.
REPOWER the SRS (Supplemental Restraint System). REFER to Restraints and Safety Systems &/or Air Bag Systems.