Land Rover Defender: Principles of Operation, Inspection and Verification

PRINCIPLES OF OPERATION

For a detailed description of the power steering system and operation, refer to the relevant description and operation section of the workshop manual.

INSPECTION AND VERIFICATION

CAUTION: Diagnosis by substitution from a donor vehicle is NOT acceptable. Substitution of control modules does not guarantee confirmation of a fault, and may also cause additional faults in the vehicle being tested and/or the donor vehicle.

NOTES:

• If a control module or a component is at fault or may be at fault and the vehicle remains under manufacturer warranty, refer to the Warranty Policy and Procedures manual, or determine if any prior approval program is in operation, prior to the installation of a new module/component.
• When performing voltage or resistance tests, always use a digital multimeter that has the resolution ability to view 3 decimal places. For example, on the 2 volts range can measure 1mV or 2 K Ohm range can measure 1 Ohm. When testing resistance always take the resistance of the digital multimeter leads into account.
• Check and rectify basic faults before beginning diagnostic routines involving pinpoint tests.
• When diagnosing steering faults if issues are found to be due to interfacing system issues. For example, anti-lock brake system, park aid, suspension, battery / charging system, etc. Make sure warranty is claimed against the interfacing system where the problem is identified not steering gear.

1. Verify the customer concern
   • If a road test is necessary make sure the vehicle is safe to do so

1. Using guidance from the symptom chart, and the symptoms defined in the electrical service diagnostic tool

2. Visually inspect for obvious signs of mechanical or electrical damage

Summary

Accident/Water Damage

WARNING: The following issues are not covered under Warranty. Retailer/Authorized repairers should not claim these issues.

• Accident damage
• Bent Steering Gear
• Bent Tie Rod
• Damage PSCM housing and Power Motor

• Water damage
• Rusty gears
• Water ingress

Visual Inspection

3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step
4. If the cause is not visually evident, verify the symptom with the customer and refer to the approved retailer /authorized repairer diagnostic tool. Alternatively check symptoms against symptom chart below and check Diagnostic Trouble Code(s) (DTC)s as appropriate and refer to the DTC index
5. Check JLR claims submission system for open campaigns. Refer to the corresponding bulletins and SSMs which may be valid for the specific customer complaint and complete the recommendations as required.

SYMPTOM CHART

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