Land Rover Discovery: Seatbelt System / Diagnosis and Testing

PRINCIPLES OF OPERATION

For a detailed description of the Safety Belt System, refer to the relevant Description and Operation section in the workshop manual. REFER to: Seatbelt System (501-20A Seatbelt System, Description and Operation).

SAFETY INFORMATION

WARNINGS:

• TO AVOID ACCIDENTAL DEPLOYMENT AND POSSIBLE PERSONAL INJURY, THE BACKUP POWER SUPPLY MUST BE DEPLETED BEFORE REPAIRING OR REPLACING ANY AIR BAG SUPPLEMENTAL RESTRAINT SYSTEM (SRS) COMPONENTS. TO DEPLETE THE BACKUP POWER SUPPLY ENERGY, DISCONNECT THE BATTERY GROUND CABLE AND WAIT ONE MINUTE.

  FAILURE TO FOLLOW THIS INSTRUCTION MAY RESULT IN PERSONAL INJURY.

• Do not use a multimeter to probe the restraints control module. It is possible for the power from the meter battery to trigger the activation of the airbags. Failure to follow this instruction may result in personal injury.

NOTES:

• It is advisable not to use a cellular phone or to have a cellular phone in close proximity when working on the restraints control module or associated systems.
• Given the legal implications of a restraints system failure, harness repairs to Air Bag module circuits are not acceptable. Where the text refers to "REPAIR the circuit", this will normally mean the replacement of a harness.

Power Supply Depletion

Before beginning any work on the SRS system or related components:

1. Set the ignition to off
2. Disconnect the battery leads, ground first
3. Wait 1 minute for the power circuit to discharge

There are comprehensive instructions on the correct procedures for SRS system repairs, refer to the relevant 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 suspect and the vehicle remains under manufacturer warranty, refer to the Warranty Policy and Procedures manual, or determine if any prior approval programme 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.

1. Verify the customer concern
2. Visually inspect for obvious signs of damage and system integrity

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 and refer to the Symptom Chart, alternatively check for Diagnostic Trouble Codes (DTCs) and refer to the DTC Index
5. Check DDW for open campaigns. Refer to the corresponding bulletins and SSMs which may be valid for the specific customer complaint and carry out the recommendations as required

SYMPTOM CHART FOR SEATBELT ROWS 1 , 2 AND 3

INERTIA REEL SEAT BELTS

The vehicle is equipped with (two row one), (three row two), and (two row three (seven seat versions only)) inertia reel seatbelts.

These seatbelts are dual sensitive, which means that they feature:

• Car sense system - A vehicle motion sensor, which locks the seatbelt webbing under braking, cornering, on steep hills and in adverse camber conditions, when parked on a steep incline or driveway or with two wheels on a high curb
• Web sense system - A webbing motion sensor, which locks when the seatbelt webbing is extracted suddenly

SEATBELT LOCKING TEST

With the vehicle stationary and on level ground take firm hold of the seatbelt webbing (on the tongue side of the upper seatbelt anchor) and withdraw sharply, the retractor should lock. Preventing further webbing release (repeat this test 3 times). Any seatbelt retractor which fails to lock must not be used and a new seatbelt must be installed.

AUTOMATIC LOCKING RETRACTORS

Some seatbelts feature an automatic locking retractor function. These can be used to secure a child seat or heavy load.

Automatic Locking Retractor Activation and Deactivation

DIAGNOSTIC GUIDE INERTIA REEL SEATBELTS

NOTE:

This test applies to the rear center seatbelt retractor installed in the seat back

CAUTION:

Do not insert any objects or tools into the buckle head

DTC INDEX

For a list of Diagnostic Trouble Codes (DTCs) that could be logged on this vehicle, please refer to Section 100-00.

REFER to: Diagnostic Trouble Code Index - DTC: Restraints Control Module (RCM) (100-00 General Information, Description and Operation).

Seatbelt system specifications

Torque Specifications

Seatbelt System - Input/ Output DiagramSupplemental Restraint System Airbag Disposal

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