B1658

Code

Other B — Body

Seat Driver Rear Up Circuit Short To Ground

Brand: Other

Type: B — Body

Views: UK: 24 EN: 31 RU: 27

AI status

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Page language: EN

Causes

Damaged or pinched wiring harness under the seat contacting chassis ground
Chafed insulation where wires pass through seat tracks or hinges
Corroded or loose connector terminals shorting to ground
Failed seat motor/actuator with internal short
Faulty seat control module or internal driver short
Water intrusion or contamination creating conductive path to ground

Symptoms

Rear-up function of driver seat does not operate
One or more fuses related to seat adjustment blow repeatedly
Seat moves erratically or stops mid-travel
DTC B1658 stored in body/seat control module
Occasional electrical burning odor or heat near seat
Related seat warnings or functionality loss (intermittent)

What to check

Read and record all stored DTCs and freeze-frame data with a scan tool
Visually inspect wiring under the seat, along tracks, and at connectors for damage, pinching, or corrosion
Check seat adjustment fuses and relays for continuity and proper rating
Inspect connectors at the seat motor/actuator and seat control module for bent pins or corrosion
With key off, perform a resistance/continuity check from the suspect circuit pin to chassis ground
Measure supply voltage and circuit voltage while commanding the rear-up function with a scan tool

Signal parameters

Normal supply voltage to seat control: battery voltage (~12 V) with ignition/accessory on
Expected voltage at actuator control pin when inactive: near supply or high-impedance (varies by design); when shorted to ground: ~0 V
Typical actuator coil resistance: low ohms (varies by model); sudden near-zero ohms to ground indicates short
Normal commanded current: depends on motor size; sustained very high current or blown fuse indicates short or motor fault
Diagnostic module output: should show open/high-impedance when not driving; short-to-ground will register as low/short status

Diagnostic algorithm

Retrieve B1658 and any related codes; note freeze-frame and occurrence conditions.
Attempt to reproduce the fault while monitoring with a scan tool. Observe whether the code sets immediately or after operation.
Visually inspect wiring, harness grommets, and connectors under and around the seat for damage, rubbing, or corrosion.
Check fuses and relays for the seat circuits; replace blown fuses only after isolating cause.
With battery connected, measure voltage at the seat control module output pin for the rear-up circuit while commanding the motor. If output is low (~0 V) when it should be high or high-impedance, suspect a short.
With ignition off and battery disconnected if required by vehicle service manual, disconnect the actuator/motor connector. Perform a continuity check between the circuit pin and chassis ground—continuity indicates a short.
If connector to motor shows open to ground, follow the wiring using the vehicle wiring diagram and perform wiggle/continuity tests section-by-section to locate the short (compress grommets, inspect under trim and through seat tracks).
If short follows to the motor/actuator, bench-test or replace the motor. If short is on module side, consider swapping seat control module or repairing wiring near module after confirming.
Repair or replace damaged wiring, terminals, or components. Protect repaired wiring with conduit, tape, or routing to avoid future rubbing.
Clear codes, perform functional test of seat rear-up, and confirm no recurrence. Re-scan for stored codes.

Likely causes

Wiring insulation worn where it rubs on metal seat frame or track
Connector pin pushed back and contacting seat body
Motor/actuator internal winding shorted to ground
Shorted output transistor inside the seat control unit
Ground strap or mounting hardware contacting exposed conductor

Fault status

⚠️ Status

Seat driver rear-up circuit short to ground detected (B1658). Circuit is seeing unintended connection to chassis ground; rear-up function may be inoperative and fuses may blow.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1-3 hours