Reports seat-track position for restraint timing and occupant protection strategy.
SENSOR GUIDE60/86
Identify the circuit first
ONE NAME. DIFFERENT SIGNALS.
Pin count is a clue, not proof. Confirm the exact architecture before resistance testing, applying voltage or judging the waveform.
TYPE 01CONSTRUCTION VARIANT
Mechanical switch
Confirm wiring, pin count and service information before testing.
Contacts connect the signal to ground or power in one physical state.
Reading the signal
Good waveform
Compare the measured signal with the specified input or command under the same operating conditions. Levels, timing and repeatability should match the installed design and a suitable verified reference. There is no universal waveform or scale for every version of this component.
Faulty waveform
An unexplained dropout, missing response, excessive noise or mismatch between command and feedback warrants further testing. First rule out a changed physical condition, incorrect probe reference, supply loss and an unsuitable scope setting; an unusual trace alone does not identify a failed component.
TYPE-SPECIFIC TESTS
+ Check the module pull-up, loaded voltage and mechanical adjustment—not continuity alone.
+ Verify the specified supply, ground, bias or termination before judging the signal.
+ Repeat the test through the complete operating range.
EXPECTED
✓ Output matches this construction type
✓ Stable levels and repeatable response
✓ Agreement with related scan data
COMMON FAULTS
— Incorrect test method for the sensor type
— Supply, ground or signal-circuit fault
— Installation, target or calibration concern
TYPE 02CONSTRUCTION VARIANT
Reed or Hall switch
Confirm wiring, pin count and service information before testing.
A magnet operates a sealed reed or powered Hall element without exposed contacts.
Reading the signal
Good waveform
Logic levels and edge transitions are consistent with the installed circuit. Pulse timing changes in the specified way as the input changes; intended index gaps or encoded features repeat correctly.
Faulty waveform
Missing or extra edges, weak switching levels, intermittent pulse loss or a stuck level can indicate supply, ground, wiring, target or sensor problems. A steady level can be normal when the target is stationary. Decode encoded signals using the correct protocol.
TYPE-SPECIFIC TESTS
+ Verify magnet alignment, power when required and a clean state change.
+ Verify the specified supply, ground, bias or termination before judging the signal.
+ Repeat the test through the complete operating range.
EXPECTED
✓ Output matches this construction type
✓ Stable levels and repeatable response
✓ Agreement with related scan data
COMMON FAULTS
— Incorrect test method for the sensor type
— Supply, ground or signal-circuit fault
— Installation, target or calibration concern
TYPE 03CONSTRUCTION VARIANT
Resistive ladder / LIN module
Confirm wiring, pin count and service information before testing.
Multiple states may be encoded as resistance or transmitted by a local module.
Reading the signal
Good waveform
Check the correct physical interface and decode the transmitted data. Valid frames, expected update timing and measurements that agree with the real input support normal operation. Pulse shape alone does not establish measurement accuracy.
Faulty waveform
Corrupted or missing frames, unexpected pauses, invalid status bits or implausible decoded values can indicate a fault. Verify supply, ground and the applicable bus before replacing the sensor; do not apply CAN waveform expectations to LIN, SENT or another interface.
TYPE-SPECIFIC TESTS
+ Identify the circuit before jumping it; compare each state with the wiring diagram and scan data.
+ Verify the specified supply, ground, bias or termination before judging the signal.
+ Repeat the test through the complete operating range.
EXPECTED
✓ Output matches this construction type
✓ Stable levels and repeatable response
✓ Agreement with related scan data
COMMON FAULTS
— Incorrect test method for the sensor type
— Supply, ground or signal-circuit fault
— Installation, target or calibration concern
Correct theory and operation
HOW IT WORKS.
Understand the sensing method, circuit and controller strategy before interpreting data or replacing the component.
01
Measured condition
Reports seat-track position for restraint timing and occupant protection strategy.
02
Signal type
Discrete or encoded state. A switch, reed element, Hall device or resistive ladder reports a physical state to a controller.
03
Controller use
The receiving controller checks range, rationality and rate of change against related inputs before setting a fault or substituting a value.
04
Installation matters
Mounting, target condition, air gap, contamination, temperature, shielding or calibration may affect the result even when the circuit is intact.
Common mistakes
AVOID THE FALSE CLUE.
Condemning the sensor before verifying powers, grounds and communication.
Using a generic value instead of vehicle-specific service information.
Checking an unloaded circuit that fails only while operating.
Ignoring mechanical, installation or calibration causes.
Replacing the component without repeating the original test.
COMPLETE TEST SEQUENCE
Compare scan status with the actual mechanical state.
Verify pull-up or pull-down voltage at the signal.
Load-test the circuit instead of relying only on continuity.
Check adjustment, latch engagement and harness movement.
Repeat the original operating condition and confirm the repair.
DO NOT CONDEMN THE SENSOR
Prove its supply, ground, signal path, physical input and calibration before replacement. Vehicle-specific specifications always win.