B1516

Code

Other B — Body

Seat Driver Occupied Switch Circuit Open

Brand: Other

Type: B — Body

Views: UK: 25 EN: 37 RU: 33

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Open or broken wiring in the seat occupied switch circuit (harness chafing under seat)
Disconnected, loose or corroded connector at the seat switch or control module
Defective seat occupied switch or pressure sensor assembly
Failed body/SRS control module input circuit
Poor ground or blown fuse affecting the switch circuit
Aftermarket seat or previous repair with incorrect wiring

DTC B1516 stored and lamp or message (airbag/occupant/seat-belt) may be illuminated
Seat belt reminder or chime not functioning as expected for driver
Occupant detection status in scan tool shows 'open' or 'not occupied' even when occupied
Intermittent faults when seat is moved or after vehicle vibration

Read DTCs and freeze-frame with a scan tool; note any related codes (SRS/body modules)
Visually inspect seat harness and connectors under the driver seat for damage, corrosion or disconnection
Backprobe the seat-occupied switch connector and measure reference voltage and signal with ignition on
Perform continuity test between switch connector and the control module input pin with connectors disconnected
Wiggle test harness and connector while observing live-data for the occupied switch

Reference supply typically 5 V or ignition-switched 12 V depending on vehicle — verify with service data
Switch closed continuity: expect low resistance (near 0 Ω to a few ohms) when switch is actuated/occupied
Switch open resistance: very high (kΩ to infinite) when switch is not actuated or circuit open
Signal voltage should change state when seat is occupied vs unoccupied (observe live-data or backprobe with ager)
No signal or floating voltage indicates open circuit or disconnected connector

Safety: follow manufacturer SRS procedures before working on seat wiring (disconnect battery and wait as required).
Retrieve and record all related codes and freeze-frame data. Clear codes and attempt to re-create to confirm persistence.
Visually inspect the driver seat underside: connectors, clips, harness routing through seat frame and seat rail areas for chafing or damage.
With connectors accessible, reconnect battery (if removed) and backprobe the seat-occupied switch connector. Verify reference supply and signal voltage with key ON while someone sits/stands to observe signal change.
If no reference or signal, disconnect connector and perform continuity check from switch pins to the control module input pin. An open indicates wiring/connector fault.
Wiggle harness and operate seat fore/aft and recline while monitoring continuity and live-data to find intermittent faults.
If wiring and connectors are good, measure resistance across the switch itself; compare to expected values in service info. Replace switch assembly if it remains open when activated.
If switch and wiring check good but code persists, test for proper input at control module connector and inspect module ground and power. Consider module replacement only after confirming harness and switch are good.
After repair, clear codes, verify live-data shows correct occupied/unoccupied behavior and perform road/functional check to confirm no reoccurrence.