B1764

Code

Other B — Body

Seat Driver Front Down Circuit Short To Ground

Brand: Other

Type: B — Body

Views: UK: 21 EN: 46 RU: 35

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Page language: EN

Causes

Damaged or chafed wiring harness with insulation worn through contacting chassis ground
Corroded, pushed-out, or damaged connector pins at the seat actuator or seat control module
Internal short in the driver front seat motor/actuator
Water intrusion or contamination in connector/junctions
Failed output transistor or driver inside the seat control module (module short to ground)
Aftermarket accessories or improper repairs that spliced into the seat circuit

Symptoms

Driver seat will not move down (no response when using control)
Blown fuse(s) for seat circuits or repeated fuse failures
Intermittent or erratic seat movement
DTC B1764 stored in seat control module or body control module
Possible burning smell or heat from seat area in severe shorts
Loss of seat memory or related seat functions

What to check

Read and record stored DTCs, freeze-frame and any related codes.
Attempt to operate the seat and note behavior; try other seat directions to isolate circuit.
Visually inspect wiring and connectors under the seat for chafe, damage, corrosion, or loose pins.
Check relevant fuses and relays; replace suspect fuses and re-test (do not repeatedly cycle fuses).
Backprobe the seat down circuit connector and measure voltage while commanding the down function.
With ignition off and battery disconnected, measure continuity/resistance between the down circuit and chassis ground to look for a short to ground.

Signal parameters

With seat module commanding 'down': output pin should be approximately battery voltage (~11–14V) to drive the motor (or appropriate polarity depending on system).
With no command: output should be high-impedance or near 0V depending on design.
Resistance from circuit wire to chassis ground (with connector disconnected) should be very high (open), not near 0Ω; a measured low ohms indicates a short to ground.
Motor coil resistance (motor disconnected) typically several ohms to tens of ohms; a very low/near-zero reading suggests an internal short.
Short-circuit current (if present) will typically show a voltage drop at the module output and may blow a fuse or cause module protection to shut down.

Diagnostic algorithm

Retrieve DTCs and freeze-frame data; record vehicle and circuit specifics.
Try to reproduce fault: command the driver front seat DOWN while monitoring behavior and fuses.
Inspect connectors and wiring under the seat for visible damage, water, or pin push-out. Repair any obvious damage.
Check fuses and replace a blown fuse once to help locate short; if fuse immediately blows, stop and proceed to isolate circuit.
With ignition OFF and battery disconnected, disconnect the seat motor/actuator connector. Measure resistance from the seat down circuit wire to chassis ground. Low resistance indicates a short in wiring or module.
If no short with motor disconnected, test the motor itself: measure coil resistance and bench-test motor briefly with a fused jumper to verify operation (use appropriate inline fuse and limit testing time).
If motor is okay but short remains, trace wiring toward the seat control module. Repair chafed/abraded sections or replace damaged harness segments. Use insulation, conduit, or reroute wiring away from sharp edges.
If short persists with harness repaired and motor disconnected, suspect seat control module output (internal driver short). Confirm by checking output pin behavior with module connected and commanding; replace module if confirmed.
After repairs, reconnect everything, clear DTCs, and verify proper operation through several cycles and wiggle tests.
Advise final inspection for water intrusion, secure routed wiring, and document repairs.

Likely causes

Wire harness chafe under the seat contacting chassis or bracket
Damaged connector pin or corrosion at the seat motor connector
Internal short in the seat down motor/actuator
Seat control module output driver failure

Fault status

⚠️ Status

B1764 — Driver front seat DOWN circuit short to ground. Control module detects low circuit voltage/low resistance when commanding DOWN; seat may not move and fuses may blow.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-3.0 hours