Part 2
Seats
Pinpoint Test AW: DTC B2730
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.
The presence of overtemperature faults (DTCs B2729, B2730, B272A and B272B) can be induced by incorrect operation of the climate controlled seat system after an initial heat setting has been attained. If a heat setting is repeatedly turned OFF and ON in an attempt to increase the seat temperature or repeatedly toggled between heat and cool modes, an overtemperature condition can result and the DTCs will be set.
- DTC B2730 (Back Over-Temp Detected) (Driver)- For heat mode, if the driver seat backrest TED (Thermo-Electric Device) temperature exceeds 110°C (230°F) continuously for more than 4 seconds in any heat mode, the DCSM (Dual Climate Controlled Seat Module) turns off the TED (Thermo-Electric Device) and enters a fan only state to recover from the over-temperature condition (recovery mode). If the TED (Thermo-Electric Device) temperature does not recover after 30 seconds, the DTC will set and the seat is disabled. If the TED (Thermo-Electric Device) does recover, the TED (Thermo-Electric Device) is re-enabled, the system continues to operate normally and the DTC will not be set. If the over-temperature condition occurs a second time within the same ignition cycle, the DTC will set and the seat is disabled.
- DTC B2730 (Back Over-Temp Detected) (Driver)- For cool mode, if the driver seat backrest TED (Thermo-Electric Device) temperature exceeds 65°C (149°F) continuously for more than 4 seconds in any cool mode, the DCSM (Dual Climate Controlled Seat Module) turns off the TED (Thermo-Electric Device) and enters a fan only state to recover from the over-temperature condition (recovery mode). If the TED (Thermo-Electric Device) temperature does not recover after 5 minutes, the DTC will set and the seat is disabled. If the TED (Thermo-Electric Device) does recover, the TED (Thermo-Electric Device) is re-enabled, the system continues to operate normally and the DTC will not be set. If the over-temperature condition occurs a second time within the same ignition cycle, the DTC will set and the seat is disabled.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Restricted backrest TED (Thermo-Electric Device) filter
- Crushed or restricted foam pad
- Backrest TED (Thermo-Electric Device) assembly
- Dual Climate Controlled Seat Module (DCSM)
PINPOINT TEST AW : DTC B2730
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 BACKREST 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 backrest TED (Thermo-Electric Device) C3034-2, circuit CHS03 (GN/BN), harness side.
- DCSM (Dual Climate Controlled Seat Module) C3265C-15, circuit RHS03 (GY/OG), harness side and driver seat backrest TED (Thermo-Electric Device) C3034-4, 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 C3378 and passenger seat side air bag module C3377.
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 BACKREST 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 backrest TED (Thermo-Electric Device) C3034 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 backrest TED (Thermo-Electric Device). REFER to Seat Backrest Thermo-Electric Device - Front Row . CLEAR the DTCs. REPEAT the self-test.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C3378 and passenger seat side air bag module C3377.
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 BACKREST 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 backrest TED (Thermo-Electric Device) C3034 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 backrest TED (Thermo-Electric Device). REFER to Seat Backrest Thermo-Electric Device - Front Row . CLEAR the DTCs. REPEAT the self-test.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C3378 and passenger seat side air bag module C3377.
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 BACKREST TED (Thermo-Electric Device) INSTALLATION AND FOR CRUSHED SEAT BACKREST
- Ignition OFF.
- Remove the driver seat. Refer to Seat- Front .
- Remove the driver seat backrest cover. Refer to Seat Backrest Cover- Front .
- Inspect the driver seat backrest for the following:
- Is the driver seat backrest TED (Thermo-Electric Device) correctly installed?
- Is the driver seat backrest foam pad crushed or restricted?
- Is the driver seat backrest climate controlled seat manifold crushed or restricted?
Is the driver seat backrest TED (Thermo-Electric Device) correctly installed and are there no signs of damage to the foam pad and manifold?
Yes
INSTALL the driver seat backrest cover and seat and GO to AW18.
No
CORRECTLY install the driver seat backrest TED (Thermo-Electric Device) or INSTALL a new driver seat backrest 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 C3378 and passenger seat side air bag module C3377.
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 BACKREST 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 C3378 and Passenger Seat Side Air Bag C3377.
- 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-9, circuit CHS14 (GN), harness side and C3265B-10 circuit CHS29 (WH/BU), harness side. Note the ambient temperature and refer to the following table.
Temperature Resistance 0-10°C (32-50°F) 2,782-1,663 ohms 10-20°C (50-68°F) 1,837-1,140 ohms 20-30°C (68-86°F) 1,260-806 ohms 30-40°C (86-104°F) 893-570 ohms 40-50°C (104-122°F) 630-428 ohms
Is the resistance within the limits indicated?
Yes
GO to AW18.
No
GO to AW17.
AW17 CHECK THE DRIVER SEAT BACKREST TED (Thermo-Electric Device) THERMISTOR
- Measure the resistance between driver seat backrest TED (Thermo-Electric Device) C3034 pin 5 and pin 8, component side. Note the ambient temperature and refer to the following table.
Temperature Resistance 0-10°C (32-50°F) 2,782-1,663 ohms 10-20°C (50-68°F) 1,837-1,140 ohms 20-30°C (68-86°F) 1,260-806 ohms 30-40°C (86-104°F) 893-570 ohms 40-50°C (104-122°F) 630-428 ohms
Is the resistance within the limits indicated?
Yes
REPAIR circuit CHS14 (GN)/VHS35 (VT/OG) or CHS29 (WH/BU)/RHS15 (GY/BN) 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 C3378 and passenger seat side air bag module C3377.
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 Backrest Thermo-Electric Device - Front Row . CLEAR the DTCs. REPEAT the self-test.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C3378 and passenger seat side air bag module C3377.
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 BACKREST 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 CHS01 (GY/VT) near DCSM (Dual Climate Controlled Seat Module) C3265A-J 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 backrest TED (Thermo-Electric Device). REFER to Seat Backrest Thermo-Electric Device - Front Row . CLEAR the DTCs. REPEAT the self-test.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C3378 and passenger seat side air bag module C3377.
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 BACKREST 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-J circuit CHS01 (GY/VT), harness side and C3265A-K, circuit RHS01 (WH/VT), 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 BACKREST TED (Thermo-Electric Device)
- Disconnect: Driver Seat Backrest TED (Thermo-Electric Device) C3034.
- Measure the resistance between driver seat backrest TED (Thermo-Electric Device) C3034 pin 1 and pin 3, component side.
Is the resistance between 0.9 and 10 ohms?
Yes
REPAIR circuit CHS01 (GY/VT) or RHS01 (WH/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 C3378 and passenger seat side air bag module C3377.
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 backrest TED (Thermo-Electric Device). REFER to Seat Backrest Thermo-Electric Device - Front Row . CLEAR the DTCs. REPEAT the self-test.
DISCONNECT the battery ground cable. CONNECT driver seat side air bag module C3378 and passenger seat side air bag module C3377.
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 backrest 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 C3378 and passenger seat side air bag module C3377.
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 C3378 and passenger seat side air bag module C3377.
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.