AU
B1708-00

BYD defines DTC B1708-00 as "Seat Driver Recline Rearward Switch Circuit Short To Ground", a body electrical system fault — Qin Plus

Safety System

BYD defines DTC B1708-00 as "Seat Driver Recline Rearward Switch Circuit Short To Ground", a body electrical system fault.

This fault indicates the Seat Control Unit (SCU) detects an abnormal 0-ohm resistance (short to ground) in the driver seat recline rearward switch circuit.

Possible causes include switch contacts stuck closed, damaged harness insulation causing a short to ground, or connector water ingress.

This fault prevents rearward seat adjustment, causes uncontrolled continuous rearward movement, or disables the seat memory function.

Some third-party data sources incorrectly label this code as "left curtain airbag resistance is 0".

Airbag faults typically use the B10XX-B19XX range or dedicated SRS fault codes, and standard OBD-II assigns B1708 to the seat adjustment circuit.

The B1708-00 fault code on the Qin Plus indicates a medium-severity fault in the driver seat recline rearward switch circuit, where the seat control unit detects a short to ground. Common causes include a stuck or water-damaged switch, or chafed under-seat wiring with exposed copper. The seat may not recline rearward, may move unexpectedly, or memory may be disabled. Visit an authorised dealer for diagnosis and repair. Typical repair cost data is available.
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Cases Logged
5
Causes
Likely Causes — Qin Plus
  • 1Burnt internal contacts, deformed spring plate, or water ingress in the driver's seat backrest rearward adjustment switch causing a constant closed short circuit.
  • 2Frequent forward and backward seat movement chafes the under-seat wiring harness, wearing through the insulation and exposing the copper wire, resulting in a short to ground.
  • 3Poor sealing of the seat wiring harness connector allows water ingress after car washing or wading, causing oxidation and a short circuit between pins or a short to ground.
  • 4Improper modifications (such as floor mat retaining clips or aftermarket seat heaters) punctured or crushed the seat wiring harness.
  • 5Internal drive circuit fault in the Seat Control Module (SCU) or Body Control Module (BCM) (low probability)
What To Do
  • 1
    Use a dedicated BYD diagnostic tool (BYD-EDS or Launch X-431) to read fault codes. Confirm if B1708-00 is a current (Active) or history (History) fault, and check for any accompanying seat-related fault codes.
  • 2
    Visually inspect the wiring harness under the driver's seat and near the slide rails. Check harness rub points against the metal frame and areas with an excessively small bend radius for damage, discoloration, or signs of water ingress.
  • 3
    Disconnect the seat adjustment switch connector. Use a multimeter to measure the resistance of the switch-side rearward adjustment position. Normal resistance is open circuit (OL). If the resistance is close to 0 Ω, replace the switch assembly.
  • 4
    Measure resistance to ground on the wiring harness side (disconnect the SCU and switch). If continuity to ground exists, inspect the wiring harness in sections. Focus on the seat slide rail retaining clip and the wiring pass-through hole below the steering column.
  • 5
    If the wiring harness is damaged, repair the insulation with heat-shrink tubing or corrugated conduit and reposition the harness retaining clips to provide additional slack. If the switch is shorted, replace the driver seat multi-direction adjustment switch assembly.
  • 6
    Check the seat control module software version. If necessary, update to the latest version to eliminate potential false faults.
  • 7
    After completing the repair, clear the fault code. Perform multi-angle seat adjustment tests (forward/backward, up/down, and backrest) to verify the memory function sets and recalls normally.
Real-World Cases
BYD DTC AI Analysis

BYD Qin Pro DM seat wiring harness worn through, causing short circuit

✓
Symptoms: Body system warning light illuminated on the instrument cluster. Diagnostic scan retrieved DTC B1708-00. Driver seat backrest rearward adjustment button inoperative. Diagnosis: Wiring harness connector beneath the driver seat found oxidised and loose. Frequent seat movement wore through the harness insulation, allowing internal wires to contact the vehicle body and short to ground. Repair: Replaced the driver seat backrest rearward adjustment switch assembly. Re-wrapped and secured the wiring harness beneath the seat. Fitted a protective sleeve to prevent future abrasion.
Original source ↗
BYD DTC AI Analysis

BYD Song PLUS EV seat switch shorted due to water ingress

✓
Symptom: Driver's seat adjustment failed suddenly while operating, and the memory function stopped working. Diagnostic scanner found DTC B1708-00 in the Seat Control Module (SCU). Disassembly found water ingress inside the side adjustment switch panel (owner spilled a drink). Testing confirmed a short circuit (abnormal continuity) in the rearward adjustment position. Repair: Replaced driver's seat adjustment switch assembly, applied waterproofing to seat harness connectors, and recalibrated memory function. All functions returned to normal.
Original source ↗
BYD DTC AI Analysis

BYD Tang DM-i seat wiring harness intermittent short circuit

✓
Symptoms: The dealership found historical fault code B1708-00 during a routine service. The owner had not noticed any obvious fault. Diagnosis: intermittent fault. While simulating seat fore/aft movement, the harness experienced excessive tension at extreme positions, causing momentary short circuits. Testing revealed microscopic damage to the harness insulation. Solution: Adjusted seat harness clip positions to increase slack, replaced the damaged harness segment, and installed high-grade abrasion-resistant protective conduit.
Original source ↗
BYD DTC AI Analysis

BYD Yuan Pro seat switch internal contacts deformed

✓
Symptoms: Driver seat backrest would not adjust rearward; forward adjustment worked normally. Scan tool retrieved DTC B1708-00. Removed the switch and tested it: pressing the rearward adjustment button gave a resistance reading near 0 ohms (normal should be several hundred ohms). Disassembled the switch and found the internal contact spring plate had deformed, causing a constant short circuit. Solution: Replaced the driver seat multi-way adjustment switch assembly. Checked the related wiring harness, found no faults, then reinstalled the components.
Original source ↗
BYD DTC AI Analysis

Modified clip pierced the BYD e2 seat wiring harness.

✓
Symptoms: Upon startup, the seat automatically moved to the rearward limit and could not be adjusted back. Diagnosis found the rearward adjustment switch stuck closed. The cause was traced to retaining clips from aftermarket floor mats piercing the wiring harness under the seat, shorting the power and signal wires. Resolution: Removed the improperly installed mat clips, repaired and re-insulated the damaged harness, replaced the seat adjustment switch damaged by the short circuit, and recalibrated the seat position memory function.
Original source ↗
Other Qin Plus Fault Codes
B1108For the BYD Song MAX (2017–2019), DTC B1108 indicates a short circuit in the PM2.5 air quality detection module (dust sensor) or its wiring harness. The sensor uses laser scattering to detect in-cabin and outside PM2.5 concentrations and transmits data to the HVAC ECU via the LIN bus or an analog signal. Short circuit conditions include: 1) Sensor power supply wire (+5V/+12V) shorted to ground 2) Signal wire shorted to power or ground 3) Short circuit in the sensor's internal photoelectric detection circuit This fault prevents the automatic climate control from switching between fresh air and recirculation based on air quality. The system enters fail-safe mode (typically forced recirculation). Severe short-circuit current can destroy the HVAC ECU sampling circuit. The system classifies this as a Level 3 severe fault and restricts vehicle operation to prevent electrical fires or controller damage. For other BYD models (such as the Qin EV, E5, and Song DM), B1108 indicates a driver-side sunload sensor fault, reflecting differences in DTC definitions across models.B110913DTC B110913 indicates an open signal circuit for the PM2.5 rapid detector (in-cabin air quality sensor). This sensor typically mounts inside the air conditioning system intake duct. It monitors in-cabin PM2.5 concentration in real time and provides data to the automatic air conditioning system for intelligent control of the air purification function. The BYD diagnostic protocol uses sub-code '13' to specifically indicate an open signal circuit. Although this fault theoretically affects a comfort feature, BYD Qin series vehicles classify it as a Level 3 (severe) fault. This classification occurs because the air conditioning system interacts with the battery thermal management system (e.g., monitoring battery cooling intake air quality). The fault can disable the automatic air conditioning mode and prevent the air purification function from operating. In extreme cases, it affects the battery compartment intake air quality assessment, triggering the 'repair immediately' strategy.B110BDTC B110B indicates a fault in the internal air pump (sampling pump) of the PM2.5 air quality detector. This pump draws cabin or outside air into the PM2.5 sensor detection chamber, enabling the laser scattering sensor to measure real-time particulate matter concentration. The air conditioning controller (or BCM) sets this DTC upon detecting an open or short circuit in the pump drive circuit, or abnormal current caused by a seized pump motor. This fault disables the "Green Clean" system, causes the instrument cluster air quality display to read abnormally or disappear, and disables the automatic fresh air/recirculation switching function. It does not affect the vehicle powertrain or core thermal management functions.B173A1ADTC B173A1A indicates the right middle-row side airbag (typically located on the side of the right second-row seat or inside the C-pillar trim panel) igniter circuit resistance measures 0 Ω. In the Supplemental Restraint System (SRS), normal airbag igniter resistance ranges between 2.0 and 5.0 Ω. A resistance of 0 Ω indicates a short to ground or a short between circuit wires, preventing the Airbag Control Unit (ACU) from establishing a normal monitoring circuit. This safety-critical fault prevents the airbag from deploying during a collision, continuously illuminates the instrument panel SRS warning lamp, and may force the entire airbag system into fail-safe mode.B173BDTC B173B indicates an abnormal electric A/C compressor speed feedback signal or a communication fault between the compressor controller and the motor. In BYD new energy models (e.g., Tang, Song, Qin, and Yuan series), this DTC belongs to the HVAC subsystem within the Body Control system and specifically involves the electric compressor closed-loop control circuit. The ECU sets this DTC when the compressor controller (IPM) fails to receive a valid pulse signal from the Hall speed sensor for more than 3 continuous seconds, or when the deviation between the detected actual speed and the target commanded speed exceeds the calibrated threshold (typically >500 rpm). This fault forces the A/C system into fail-safe mode and stops compressor operation. Symptoms include a complete lack of cooling, intermittent cooling, or a sharp decrease in cooling performance. The instrument cluster A/C warning lamp may also illuminate. Prolonged operation with this fault can degrade high-voltage system insulation or cause controller overcurrent damage.
Common problems reported for Qin Plus →Qin Plus overview →
Data confidence: Official This information is for reference only. Always consult a qualified technician for diagnosis and repair. Do not attempt high-voltage system repairs yourself.