AU
C001500

DTC C001500 indicates the IPB (Integrated Power Brake) ECU detects a circuit fault while actuating the right front wheel outlet valve (RF Outlet Valve, a Normally Closed Valve) — Atto 8

Braking System

DTC C001500 indicates the IPB (Integrated Power Brake) ECU detects a circuit fault while actuating the right front wheel outlet valve (RF Outlet Valve, a Normally Closed Valve).

This solenoid valve returns brake fluid from the right front wheel cylinder to the reservoir or master cylinder during the ABS/ESC pressure release phase, enabling precise brake force control.

Root causes include an open or short circuit in the solenoid coil, a damaged ECU on-board driver chip (MOSFET/ASIC), abnormal current feedback (e.g., mechanical valve sticking causing a current over-limit), or a wiring harness fault.

This fault prevents the right front wheel from achieving accurate pressure build-up, hold, and release cycles, and disables ABS/ESC functions.

In extreme cases, it causes right front wheel brake drag and uneven brake force distribution, severely compromising driving safety.

The C001500 fault code on the Atto 8 indicates a medium-severity circuit fault in the IPB right front brake outlet valve, which can disable ABS/ESC control for that wheel. Common causes include a faulty solenoid coil or a damaged IPB ECU valve driver circuit. The recommended fix is to visit an authorised dealer for diagnosis and repair or replacement. Typical repair cost data is available.
3
Cases Logged
5
Causes
Likely Causes — Atto 8
  • 1Open circuit, inter-turn short circuit, or short to housing in the right front outlet valve solenoid coil inside the IPB assembly
  • 2Damaged onboard solenoid valve drive circuit in the IPB control unit (ECU) (e.g., L9305 chip or high-side/low-side driver transistor breakdown)
  • 3IPB wiring harness connector (usually a 32-pin or 48-pin plug): Oxidation, backed-out terminals, corrosion from water ingress, or poor contact at the corresponding pins.
  • 4Severe brake fluid contamination (excessive water content or impurities) causes the solenoid valve spool to stick, resulting in the drive current exceeding the calibrated threshold.
  • 5IPB power supply system fault (battery voltage below 9V or above 16V, or excessive ground resistance) causes false protection in the drive circuit.
What To Do
  • 1
    Diagnostic Tool Reading: Use a BYD VDS or Launch X-431 diagnostic tool to read the complete DTC, freeze frame data, and Fault Occurrence Counter (FDC). Record key data at the time of the fault, such as vehicle speed, wheel speed, and brake pedal travel.
  • 2
    Visual inspection: Check the IPB assembly (located on the left side of the front bulkhead in the engine compartment) for impact deformation and brake fluid leaks. Inspect wiring harness connectors X1 and X2 specifically for looseness, failed locking tabs, damaged sealing rings, or water stains/corrosion.
  • 3
    Solenoid valve resistance measurement: Disconnect the IPB connector. Use a multimeter to measure the resistance between the two terminals of the right front outlet valve solenoid (standard value: approximately 2.0-10.0Ω at 20°C; refer to the vehicle repair manual for exact specifications). If the resistance is infinite (open circuit) or close to 0Ω (short circuit), this indicates an internal coil fault.
  • 4
    Harness continuity test: Measure continuity between the IPB connector valve body side pin and the corresponding ECU side pin. Check for an open circuit, short to power, or short to ground. Measure the circuit insulation resistance; it must be greater than 10MΩ.
  • 5
    Power supply and ground check: Use an oscilloscope or multimeter to measure the voltage at the IPB power supply pins (constant B+, ignition IG1) and the voltage drop at the ground pins. Verify the voltage is 12-14V with the engine running and the ground voltage drop is less than 0.1V.
  • 6
    Actuation test verification: Connect the diagnostic tool and perform the “Solenoid Valve Actuation Test” or “Hydraulic Unit Function Test”. Listen for a crisp “click” actuation sound from the right front outlet valve. If no sound occurs or the diagnostic tool reports a drive failure, diagnose a mechanically stuck valve body or an ECU drive circuit fault.
  • 7
    Component replacement: After confirming the fault, replace the IPB electro-hydraulic module assembly (Example Song PLUS DM-i spare part number: 6A-3505010-XX). Note: Recover brake fluid from the old module before replacement to prevent contamination.
  • 8
    System calibration and bleeding: After replacement, use the diagnostic tool to perform the "Brake Line Automatic Bleeding" procedure (requires continuously pumping the brake pedal), then perform "ESC Sensor Calibration", "Longitudinal Acceleration Sensor Calibration", and "Steering Angle Sensor Calibration".
  • 9
    Road test verification: Clear all fault codes. Perform a static brake pedal test. Confirm no leaks exist, then perform emergency braking tests at low speed (20 km/h) and high speed (above 60 km/h). Verify the ABS operates normally, there is no abnormal brake drag, and the fault code does not recur.
Real-World Cases
BYD DTC AI Analysis

BYD Song PLUS DM-i ABS/ESP warning, right front outlet valve driver circuit fault

✓
While driving, the ABS and ESC warning lights came on. Scanned DTC C001500 (Right Front Outlet Valve Drive Fault). Checked IPB wiring harness connections; normal. Measured internal solenoid resistance; open circuit. Confirmed open circuit in right front normally closed valve coil inside IPB assembly. Replaced IPB electro-hydraulic module assembly. Performed sensor calibration. System returned to normal.
Original source ↗
BYD DTC AI Analysis

Dashboard ABS warning light stays on. Diagnosis: right front outlet valve circuit fault.

✓
After starting the vehicle, the ABS warning light remained illuminated and the system failed its self-test. The scan tool retrieved DTC C0015 (right front outlet valve fault). Inspection revealed an internal circuit fault in the right front outlet valve within the ABS Hydraulic Control Unit (HCU); the solenoid valve would not actuate. The external wiring harness showed no damage, confirming an internal HCU failure. Replacing the ABS Hydraulic Control Unit assembly resolved the fault.
Original source ↗
BYD DTC AI Analysis

ESC warning light illuminated while driving; faulty normally closed valve in right front wheel caused abnormal braking.

✓
While driving, the ABS and ESC warning lights suddenly illuminated and the driver felt abnormal brake pedal travel. The scan tool displayed C0015-00 (right front normally closed valve fault). Testing revealed the right front outlet valve resistance fell outside the standard range (2-10 ohms) and the valve produced no operating sound during the actuator test. Confirmed an internal IPB solenoid valve fault. Replaced the IPB assembly, bled the brakes and calibrated the ESC. The fault codes cleared and the road test returned normal results.
Original source ↗
Other Atto 8 Fault Codes
B110811This DTC indicates a short circuit in the air conditioning system PM2.5 air quality sensor (rapid detector). Specifically, abnormal continuity exists between the sensor power supply circuit or signal output circuit and body ground or battery positive. This causes the control module (ACU/air conditioning controller) to detect abnormal current or a voltage signal outside the valid range (typically 0V or supply voltage). The PM2.5 sensor monitors internal and external particulate concentrations, providing the data the automatic air conditioning system uses to switch between fresh air and recirculation modes. A short circuit disables the air quality monitoring function. This fault may force the air conditioning system into recirculation protection mode and trigger related thermal management system faults, as the air conditioning system acts as a key actuator in vehicle thermal management. In severe cases, the short circuit current can damage the internal sampling circuit of the air conditioning controller or overheat the wiring harness.B1109DTC B1109 indicates an open circuit in the communication line between the air conditioning system PM2.5 air quality sensor (dust concentration sensor) and the air conditioning control unit (AC ECU), or an open circuit within the sensor internal circuitry. Typically located in the air conditioning intake duct, this sensor monitors real-time PM2.5 particle concentration inside and outside the vehicle. It provides data to the automatic air conditioning system for intelligent switching between fresh air and recirculation modes and for controlling the air purification device. During an open circuit fault, the AC ECU cannot receive the air quality signal, triggering the system fail-safe mode. Symptoms typically include failure of the automatic recirculation function, abnormal air purification indicator light operation, or abnormal air quality data displayed on the air conditioning panel. Severe cases may compromise the cabin environment control strategy, but do not directly affect vehicle driving safety.B110A02DTC B110A02 indicates the thermal management master control unit (HVAC ECU) or body control module (BCM) failed to receive valid CAN data frames from the PM2.5 air quality sensor over consecutive communication cycles (typically 500ms per cycle). The sensor typically mounts at the HVAC unit air inlet or behind the glove box and transmits real-time particulate concentration data (unit: μg/m³) to the HVAC controller via the CAN bus. The fault is essentially a communication link layer timeout. Potential causes include physical layer wiring faults, sensor power supply failures, sensor internal MCU lockup, or CAN network topology damage. Although this non-critical fault does not directly affect driving safety, it disables the intelligent air purification strategy and the automatic fresh air/recirculation switching function. In extreme cases, it triggers a thermal management system degraded mode, limiting compressor power or fixing the air flap position.B110B07This fault code indicates abnormal operation of the internal air pump (sampling pump) in the PM2.5 air quality detection module. The PM2.5 detector uses the laser scattering principle to measure particulate concentration and requires a built-in air pump to draw ambient air into the detection chamber at a constant flow rate. The ECU sets this code when it detects an open or short in the air pump drive circuit, abnormal current (stall or free-running), or abnormal speed feedback. This fault causes the automatic air conditioning system to lose air quality sensing capability, preventing automatic switching between fresh air and recirculation modes. The instrument cluster air quality display may show '--' or a fixed value, but the fault does not affect the vehicle powertrain or basic air conditioning cooling and heating functions.B173CDTC B173C indicates the Supplemental Restraint System (SRS) detects the Right Second Row Side Airbag squib circuit resistance exceeds the calibrated threshold (typically >4.5Ω). This fault is an active diagnostic result of the SRS system, indicating a high-resistance condition in the circuit between the Airbag Control Unit (ACU) and the airbag module. Causes for excessive resistance include increased contact resistance, a partially broken wiring harness, terminal oxidation, or an aging squib wire inside the airbag module. This fault causes the system to mark the airbag circuit as 'unreliable', meaning the airbag may fail to deploy during a collision. The fault typically illuminates the instrument cluster airbag warning light (SRS light) continuously, and some models also sound a warning buzzer.
Common problems reported for Atto 8 →Atto 8 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.