Inspection and verification (Discovery 3)

1. Check the validity of the customer's complaint.

2. Confirm which, if any, warning lights and/or messages are illuminated/displayed on the instrument cluster. For a list of messages, refer to the relevant section in the workshop manual.

3. Perform a visual inspection to detect obvious signs of mechanical or electrical damage.

Mechanical factors	Electrical factors
Oil leak from differential Installing the sensor	Power Fuse(s) Physical damage or water ingress into the wiring harness Loose or corroded electrical connectors CAN electrical circuits (Control Area Network) Sensors Electronic control unit for rear differential

4. If an obvious cause for a problem you have identified or a problem described by the customer is found, resolve it before moving on to further action. (if possible).

5. Use an approved diagnostic system or scanning device (tester) to read all Diagnostic Trouble Codes (DTCs) before proceeding to the Fault Indication Table or DTC Code Index. Erase all DTC codes after troubleshooting.

The article is based on information from the website lrman.ru

Table of signs of malfunction

Sign of malfunction	Possible message	Other possible warnings	Possible reasons	Action
Operation with limited performance in the presence of a fault	Rear differential failure	Transmission Overheat Warning Light Turns On Rear Differential/Transmission Malfunction Indicator Lamp Comes On	Water entering the wiring harness or electrical connectors Limitation of differential characteristics Increased differential tolerances Internal malfunction Rear differential control unit malfunction (rear differential control unit)	Visually inspect the wiring harness and electrical connectors for water ingress. If you suspect a module, refer to the warranty policy and procedures manual.
Rear differential overheating	Slowdown due to overheating of the rear differential	Transmission Overheat Warning Light Turns On	Incorrect oil level Incorrect oil specification Sensor malfunction Internal malfunction	Check the oil level and specification. Refer to the relevant section in the service station manual.