B2896

Code

Generic B — Body

Seat Heater Circuit Fault

Brand: Generic

Type: B — Body

Views: UK: 7 EN: 10 RU: 11

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Blown fuse or tripped circuit breaker for seat heater
Open or shorted wiring harness in or under the seat (damage from movement)
Corroded or loose connector at seat module or heater pad
Failed seat heating element (heater pad) or internal short
Faulty seat heater control module or body control module output
Damaged or shorted seat temperature sensor (thermistor)

Symptoms

Seat heater does not heat or heats intermittently
Partial heating (one section of the seat only)
Seat heater warning lamp or message on dash
DTC B2896 stored in memory; possible reduced or disabled seat heating
Blown fuse(s) on repeated activation

What to check

Read stored DTC(s) and freeze frame data with a scan tool; note ignition/key state when fault set
Visually inspect fuses, relays and seat wiring harness routing (hinge area) for damage
Inspect connectors at seat module, heater pad and instrument panel for corrosion or poor contact
Check for signs of water ingress or contamination in seat cushion
Wiggle test wiring while observing the scan tool or heater operation for intermittent faults
Verify power (switched 12V) and ground at seat heater feed with ignition ON

Signal parameters

Power feed (switched 12V) to seat heater: battery voltage (~11.5–13.0 V) with ignition/accessory on (verify with service manual)
Control output from module: typically switched ground or PWM signal — 0–12 V range depending on design
Heater pad resistance (typical): low ohms. Many pads measure in the range of ~0.5–10 Ω depending on design; consult OEM spec
Seat temperature sensor (thermistor) resistance: varies with temperature; commonly in the kilo-ohm range at room temperature (consult service chart)
Circuit continuity to ground: near 0 Ω; check for short to chassis or to battery positive if fuse is blowing

Diagnostic algorithm

Retrieve and record all codes and data with a scan tool. Clear codes and attempt to re-create the fault to confirm repeatability.
Perform a visual inspection of fuses, relays and seat wiring harnesses (focus on seat rail/hinge areas). Repair obvious damage.
Verify power and ground at the seat heater power feed connector with ignition ON. If no power, trace feed back to fuse/relay and repair.
Inspect connectors for corrosion, bent pins, or water; disconnect and inspect mating surfaces. Repair/clean and reconnect.
Measure resistance of the heater pad between its power and return terminals. Compare to OEM specification. An open or very high resistance indicates a failed pad.
Measure resistance of the seat temperature sensor (thermistor) and compare to temperature/ohm chart in the service manual. Check for shorted sensor.
If heater pad resistance is low but fuse blows or module reports overcurrent, check for short to ground or short to battery voltage on control wiring.
Monitor module output with a scope or multimeter while operating seat heat controls. Check for expected PWM or switched output and for correct switching behavior.
If wiring and components check OK, test or substitute seat heater control module/seat module (or BCM output) per service manual procedures.
If the heater pad is faulty, repair or replace the pad/seat cushion assembly following manufacturer instructions (adhesive/trim removal). Observe SRS/airbag connector precautions and disconnect battery as required.
After repairs, clear codes and verify proper operation through all heat settings and perform a final scan to confirm no new codes.

Likely causes

Damaged wiring or connector at the seat (wear at the seat hinge/wire loom)
Failed heater pad (open or shorted element)
Blown fuse or poor power/ground to the seat heater circuit
Failed seat heater control/output in seat module
Corroded or contaminated connector causing intermittent contact

Fault status

⚠️ Status

Stored when the vehicle control module detects a fault condition in the seat heater circuit (open, short, overcurrent, or sensor fault). May disable heating and trigger a dash message or indicator.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-2.5 hours