What Does B1704 Mean?
This code indicates that the Body Control Module (BCM) or Seat Control Module has detected a short to ground in the driver's seat recline forward switch circuit. The control module monitors the electrical signal from the switch that allows the seat backrest to tilt forward, and has detected that the circuit voltage is being pulled to ground when it should not be. This prevents proper communication between the switch and the module, disabling the recline forward function.
Common Causes
45%
Damaged or chafed wiring harness under the seat causing short to ground on switch circuit
30%
Faulty driver seat recline forward switch with internal short to ground
15%
Corroded or moisture-damaged connector at seat switch or module causing short circuit
10%
Failed seat control module with internal circuit fault detecting false short to ground
Diagnostic Steps
1
Step 1: Perform visual inspection of driver seat wiring harness, particularly under seat rails and at pivot points, looking for chafed, pinched, or damaged wires contacting metal seat frame. Check all connectors for corrosion, moisture intrusion, or pushed-back pins.
2
Step 2: Disconnect the driver seat recline forward switch connector. Using a digital multimeter, measure resistance between the switch signal circuit terminal (at harness side) and vehicle ground. Reading should be infinite ohms (open circuit); low resistance indicates wiring harness short to ground.
3
Step 3: If harness tests good, measure resistance across the recline forward switch terminals with switch disconnected. Compare readings to manufacturer specifications in both pressed and unpressed states. Internal short will show zero or very low resistance to ground terminal when it should be open.
4
Step 4: If switch and harness test normal, check for proper voltage supply and ground at switch connector with key on using multimeter. Verify module is providing correct reference voltage (typically 5V or 12V depending on system design).
5
Step 5: Clear codes and operate the recline forward switch while monitoring live data if available. If code immediately returns with switch operation, replace faulty switch. If code sets without input, suspect module fault.
6
Step 6: After repair (wiring repair, switch or module replacement), clear codes, cycle switch through full operation multiple times, and verify code does not return and function operates normally.
Estimated Repair Cost
$120 - $550
Parts + labor, varies by vehicle and location
This code indicates that the Body Control Module (BCM) or Seat Control Module has detected a short to ground in the driver's seat recline forward switch circuit. The control module monitors the electrical signal from the switch that allows the seat backrest to tilt forward, and has detected that the...
The most common cause of B1704 (Seat Driver Recline Forward Switch Circuit Short To Ground) is: Damaged or chafed wiring harness under the seat causing short to ground on switch circuit
Typical repair costs for B1704 range from $120 to $550, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This is a non-critical comfort feature fault that does not affect vehicle safety or drivability. The vehicle is safe to drive, but the driver seat recline forward function will be inoperative until repaired. Repair at convenience.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1704 to identify the root cause.
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Quick Info
Category
Body
System
Power Seat Control System
Difficulty
Type
Manufacturer
Recommended Tools
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