DIAGNOSIS AND TESTING

Overview

The heating and ventilation system is a fairly straightforward design requiring no specialized techniques for diagnosis.

Follow the visual inspection below and refer to the diagnostic trouble code (DTC) index for electrical faults.

For information on the description and operation of the system, refer to the relevant section of the workshop manual.

Inspection and Verification

Verify the customer concern.

Visually inspect for obvious mechanical or electrical faults.

Visual inspection

Mechanical	Electrical
Intake ducts blocked/restricted Coolant level Air in cooling system Distribution motors and flaps	Fuses Harnesses and connectors Blower relay Blower control module Blower assembly Automatic temperature control module

If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step

Use the approved diagnostic system or a scan tool to retrieve any DTCs before moving onto the symptom chart or DTC index.

Symptom chart

Symptom	Possible causes	Action
Air intake stuck in one position	Sensor fault Distribution motor fault	Check for DTCs indicating a sensor fault (refer to the DTC index below). Carry out the distribution motor self-test. Refer to the relevant section of the workshop manual.
Excessive blower noise	Blower mechanical fault Debris drawn into the blower Solar sensor fault	Check for mechanical faults/debris in the blower motor or fixings. Check for DTCs indicating a sensor fault.
Unable to control the air flow or temperature	Distribution motor fault(s) Control module fault	Carry out the distribution motor self-test. Refer to the relevant section of the workshop manual. Check for DTCs indicating a module fault (refer to the DTC index below).
No hot air	Cooling system fault Viscous fan locked Distribution motor fault(s) Control module fault	Check the coolant level, viscous fan operation, etc. Carry out the distribution motor self-test. Refer to the relevant section of the workshop manual. Check for DTCs indicating a module fault (refer to the DTC index below).

DTC index

NOTES:

Generic scan tools may not read the codes listed, or may read only 5-digit codes. Match the 5 digits from the scan tool to the first 5 digits of the 7-digit code listed to identify the fault (the last 2 digits give extra information read by the manufacturer-approved diagnostic system).
For a full list of climate control DTCs, refer to the Control Components section of the workshop manual.

DTC	Description	Possible causes	Action
B1A5911	Sensor 5 Volt Supply	Ambient air temperature sensor 5 volt supply short circuit to ground	Refer to the electrical guide and check the ambient air temperature sensor circuit. Refer to the guided diagnostic routine for this code on the approved diagnostic system.
B1A6312	Right Solar Sensor	Right-hand solar sensor signal short circuit to 5 volts	Refer to the electrical guides and check the right-hand sunlight sensor sensor circuit. Refer to the guided diagnostic routine for this code on the approved diagnostic system.
B1A6412	Left Solar Sensor	Left-hand solar sensor signal short circuit to 5 volts	Refer to the electrical guides and check the left-hand sunlight sensor sensor circuit. Refer to the guided diagnostic routine for this code on the approved diagnostic system.
B1B6013	Feedback Potentiometer Circuit	Air intake stuck in one position Feedback potentiometer circuit high resistance	Check the feedback potentiometer/air temperature mode motor circuits. Refer to the electrical guides.
B1B6711	Air Intake Servo Potentiometer Circuit	Recirculation motor signal short circuit to ground	Check the intake air motor circuit. Refer to the electrical guides. Refer to the guided diagnostic routine for this code on the approved diagnostic system.
B1B6715	Air Intake Servo Potentiometer Circuit	Recirculation motor signal high resistance Recirculation motor signal short circuit to power	Check the intake air motor circuit. Refer to the electrical guides. Refer to the guided diagnostic routine for this code on the approved diagnostic system.
B1B6801	Air Intake Servo Motor	Recirculation motor fault	Check the intake air motor circuit. Refer to the electrical guides. Refer to the guided diagnostic routine for this code on the approved diagnostic system.
B1B7400	Foot/Defrost Damper Actuator	Actuator mechanical fault Actuator overheating Actuator circuit high resistance Actuator circuit short circuit Actuator power failure	Check for mechanical faults with the face/feet distribution motor (see visual inspection). Refer to the guided diagnostic routine for this code on the approved diagnostic system.
B1B7449	Foot/Defrost Damper Actuator	Actuator internal fault	Check the face/feet distribution motor operation. Refer to the guided diagnostic routine for this code on the approved diagnostic system.
B1B7700	Front Right Air Blend Stepper Actuator	Actuator mechanical fault Actuator overheating Actuator circuit high resistance Actuator circuit short circuit Actuator power failure	Check for the right-hand air temperature motor mechanical faults (see visual inspection). Refer to the guided diagnostic routine for this code on the approved diagnostic system.
B1B7749	Front Right Air Blend Stepper Actuator	Actuator internal fault	Refer to the guided diagnostic routine for this code on the approved diagnostic system.

Published: 11-May-2011

2007.0 Range Rover Sport (LS), 412-02A

Heating and Ventilation (G830727)