Front Seats — 2016 workshop reference 1057

DTC B272B

Refer to Wiring Diagrams Cell 119 for schematic and connector information.

Normal Operation and Fault Conditions

The SCME monitors seat backrest temperature while it supplies voltage and ground to both blower motors. The SCME also supplies a variable voltage signal to control the blower speed. Cabin air enters the blower through a filter attached to the blower motor housing. Heated or cooled air exits the blower motor and flows through the foam pad.

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Conditions
	B272B Passenger Back Over-Temp Detected	If the passenger seat backrest blower motor temperature exceeds 70° C (158° F) in cool mode or 85° C (185° F) in heat mode for more than 4 seconds, the SCME shuts down the passenger seat system and sets this DTC.

DTC

Description

Fault Trigger Conditions

B272B Passenger Back

Over-Temp Detected

If the passenger seat backrest blower motor temperature exceeds 70° C (158° F) in cool mode or 85° C (185° F) in heat mode for more than 4 seconds, the SCME shuts down the passenger seat system and sets this DTC.

Possible Causes

Wiring, terminals or connectors Restricted blower motor filter Crushed or restricted backrest foam pad Backrest blower motor SCME

PINPOINT TEST AA : DTC B272B

WARNING: Incorrect repair techniques or actions can cause an accidental Supplemental Restraint System (SRS) deployment. Never compromise or depart from these instructions. Failure to precisely follow all instructions could result in serious personal injury from an accidental deployment.

AA1 CHECK THE SCME (FRONT SEAT CLIMATE CONTROL MODULE) FOR ON-DEMAND DIAGNOSTIC TROUBLE CODES (DTCS)

Start the vehicle and set the passenger seat to HIGH heat. Using a diagnostic scan tool, perform the SCME self-test.

Was DTC B272B retrieved on-demand during the self-test?

Yes	GO to AA2
No	GO to AA5

AA2 CHECK THE PASSENGER SEAT BACKREST BLOWER MOTOR THERMISTOR CIRCUITS FOR A SHORT TO GROUND

REFER to: Supplemental Restraint System (SRS) Depowering (501-20B Supplemental Restraint System, General Procedures). Disconnect: Passenger Side Airbag In-line C219. Disconnect: SCME C3265B. Disconnect: Passenger Seat Backrest Blower Motor C3039. Measure:

Click to display connectors

Positive Lead	Measurement / Action	Negative Lead
C3265B-4		Ground
C3265B-5		Ground

Are the resistances greater than 10,000 ohms?

Yes	GO to AA3
No	REPAIR the circuit in question. GO to AA22

AA3 CHECK THE PASSENGER SEAT BACKREST BLOWER MOTOR THERMISTOR AND WIRING

Connect: Passenger Seat Backrest Blower Motor C3039. Measure:

Click to display connectors

Positive Lead	Measurement / Action	Negative Lead
C3265B-4		C3265B-5

Compare the measured resistance value with the following table:

Ambient Temperature	Resistance

Source reference 1057

2016 Mustang workshop publication supplied to Mustang Atlas. Original technical text and illustrations; HTML formatting by Mustang Atlas. Source page numbering is retained for traceability. Follow the configuration, revision, warnings, and cross-references in the material. About this edition.