B113C

Code

Generic B — Body

Passenger presence sensor circuit short to ground

Brand: Generic

Type: B — Body

Views: UK: 12 EN: 28 RU: 10

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Damaged or chafed wiring harness shorting to vehicle ground
Corroded, loose, or contaminated connector at the passenger presence sensor or module
Faulty passenger presence sensor mat (resistive or pressure sensor) with internal short
Incorrectly routed or pinched wires after seat service or modification
Seat module or SRS control unit internal fault
Water or foreign debris intrusion into the sensor area or connector

Retrieve codes and freeze-frame with an OBD-II/SRS-capable scan tool; record related codes
Visually inspect passenger seat area, connectors, and harness routing for damage, corrosion, or water
Backprobe the sensor connector and observe live data while key on; note abnormal voltage or steady 0V
Disconnect passenger presence sensor and note code reaction (consult OEM procedure first)
Perform continuity and short-to-ground checks on suspect circuit wires with a digital multimeter
Wiggle test the seat harness and connectors while monitoring live data for intermittent faults

Typical signal line behavior: should vary within a low-voltage range (consult OEM) rather than read 0V steady; a short to ground will approximate 0V
With ignition ON and sensor connected, expect a sensor supply voltage from the SRS module (commonly a low-voltage reference); a short to ground will pull that reference toward 0V
Open circuit will show very high resistance (near infinite) between signal and module; short to ground will show very low resistance (< a few ohms) between signal and chassis ground
Exact voltages/resistances are vehicle and sensor-specific—refer to OEM specification for definitive values before replacing components

Read and record DTC(s) and live data from the SRS/occupant classification module. Note any related codes.
Review service history for seat work or modifications. Visually inspect connectors, carpet, and seat frame for damage or contamination.
With ignition OFF, disconnect battery per SRS safety procedure and wait the manufacturer-specified time before handling SRS components.
Visually inspect the passenger presence sensor mat and connector. Unplug and inspect pins for corrosion, bent pins, or foreign material.
With battery reconnected and key ON (follow safety cautions), backprobe the sensor connector. Measure voltage on supply and signal pins; look for ~0V (indicates short to ground) or abnormal readings.
Using a multimeter, check continuity between the signal/supply wires and chassis ground. A near-zero resistance indicates a short to ground.
If a short is present, isolate by disconnecting sections of the harness (unplug seat module, unplug connectors in-line) and retest to localize the short.
Wiggle the harness and seat while monitoring live data to catch intermittent shorts from chafing or movement.
If wiring and connectors test OK, swap or bench-test the passenger presence sensor mat (if serviceable) or replace with a known-good sensor per OEM guidance.
After repair, clear codes and verify correct occupant detection operation with an appropriate scan tool and functional test. Confirm SRS lamp is extinguished and no related codes return.

Connector at the seat occupation sensor has corrosion or bent pins, causing a grounded pin
Wiring insulation worn where harness contacts seat frame or chassis, creating a ground short
Sensor mat has internal short from physical damage, moisture, or manufacturing failure
Aftermarket seat heating, audio, or electrical work introduced a splice that grounded the sensor circuit
Faulty seat control module or occupant classification module reporting a ground on the input