Summary: B2060 is an OBD-II DTC commonly described as an ABS malfunction. In the real-world NHTSA complaint provided, B2060 appeared together with C1931 abnormal leak of brake ACC pressure and a notably low brake fluid condition, suggesting a possible link between ABS operation and hydraulic/brake-fluid issues. The information below combines these observations with general OBD-II code context from Wikipedia and standard code definitions from GitHub-style repositories. Because the available data include a single NHTSA report for this exact pairing, probability estimates for causes are presented with explicit caveats.

Summary: B2060 is an OBD-II DTC commonly described as an ABS malfunction. In the real-world NHTSA complaint provided, B2060 appeared together with C1931 (abnormal leak of brake ACC pressure) and a notably low brake fluid condition, suggesting a possible link between ABS operation and hydraulic/brake-fluid issues. The information below combines these observations with general OBD-II code context from Wikipedia and standard code definitions from GitHub-style repositories. Because the available data include a single NHTSA report for this exact pairing, probability estimates for causes are presented with explicit caveats.

Summary

• Primary symptom context: ABS system fault code B2060, often tied to braking system warnings. In the cited case, the driver also saw brake-system warnings and a significantly low brake fluid level, with no obvious external leak detected. This points toward a hydraulic issue (fluid loss) that can affect ABS operation (C1931). See NHTSA complaint reference for the scenario and codes.
• DTC context: B2060 is a body-code style DTC in many OBD-II implementations and is frequently labeled as an ABS malfunction in OEM contexts; exact definition can vary by vehicle and OEM. Wikipedia provides generic coverage of how OBD-II body codes and ABS-related issues are diagnosed in the Powertrain/Body/Chassis code family, but OEM-specific definitions will vary.
• With limited published data for B2060 alone, the diagnostic approach should center on confirming ABS integrity while ruling in/out brake-fluid-related causes and internal hydraulic leaks as suggested by the accompanying C1931 code. See citations for the sources of these interpretations.

1) Safety first

• ABS-related faults can be accompanied by reduced braking performance or unexpected pedal feel. If you experience a severe loss of braking or a hard pedal, do not drive the vehicle; tow it to a repair facility.
• If brake-fluid level is visibly low, do not assume a quick top-up will fix the issue; fluid loss typically indicates a leak or internal failure that must be repaired.

2) Symptom and code correlation

• Primary code: B2060 (ABS malfunction).
• Often observed with braking-system warnings (BRAKE, BRAKE SYSTEM, ABS) and possibly with C1931 (abnormal leak of brake ACC pressure) when hydraulic pressure is compromised.
• Note: In the NHTSA case, brake-fluid level was significantly low; no external leak was observed at first glance. This helps orient the diagnostic path toward internal leaks or ABS hydraulic components.

3) Quick checks (before deep-dive)

• Scan for all DTCs and freeze-frame data. Confirm B2060 and any related codes (e.g., C1931). Check for pending/trouble codes that may illuminate intermittent issues.
• Visually inspect for obvious external brake-fluid leaks at:
  • Master cylinder reservoir and cap
  • Brake hoses, fittings, and calipers
  • ABS hydraulic control unit (if accessible) and nearby lines
• Check brake-fluid level and condition. Do not top up without identifying and repairing the root cause of any loss.

4) Likely causes (interpretation based on the available data)

• Primary candidate (most consistent with the complaint pattern): Internal brake-fluid leak or hydraulic failure affecting the ABS hydraulic control unit (HCU) or master cylinder.

• Secondary candidate: ABS pump/motor or hydraulic control unit (HCU) failure, including internal leaks in the HCU or failed solenoids that prevent proper pressure modulation.

• Tertiary candidate: Electrical/communication fault in the ABS control module or wiring harness (CAN bus/ground issues, fuses). These can produce B2060 along with other ABS/warning codes.

• External hydraulic leaks (lines, hoses, calipers) without obvious signs could be masked and require pressure/dye testing to locate.

• Note: The exact probability distribution is constrained by the single NHTSA report; probabilities below are qualitative and informed by the symptom pattern more than by robust statistics. If more reports exist, update the probabilities accordingly.

5) Diagnostic flow (step-by-step)

Baseline verification

• Confirm B2060 and any other ABS-related codes. Record freeze-frame data and any sensor readings if available.
• Confirm brake-fluid level. If low, note the level, look for signs of recent activity (wet floors, fresh fluid on components), and prepare to locate the leak source.

Visual and mechanical inspection

• Inspect master cylinder and reservoir for leaks or internal fault indicators (e.g., fluid seepage around the piston seals; check for cross-leaks).
• Inspect brake lines and hoses for cracking, pooling, or signs of wear; inspect wheel cylinders/calipers for seepage (especially in older or higher-use vehicles; Prius may have integrated calipers with monoblock designs).
• Inspect ABS hydraulic control unit (HCU) and its connections for signs of leakage or damage. Look for fluid around the HCU, damp wiring, or corrosion.
• Check for signs of fluid intrusion into the passenger compartment/ECU area if moisture is present.

Electrical/system checks

• Verify power, ground, and CAN bus wiring to the ABS/Traction Control System (EBCM/ABS control module). Check relevant fuses and relays.
• Use a diagnostic scan tool capable of ABS live data to monitor wheel-speed sensor signals, ABS modulator activity, and hydraulic pressure readings if available.
• Check for misalignment or damage to wheel-speed sensors and tone rings; damaged sensors can contribute to ABS faults that trigger B2060 in some vehicles.

Functional/pressure checks

• If capable, observe ABS pump run/pressure during a simulated ABS activation (e.g., on a safe test surface with trained personnel). In many vehicles, this is done via specialized equipment (bi-directional scan tool, appropriate service procedures).
• If a suspected pump/HCU leak is present, perform a brake-hose or HCU pressure test as specified by OEM procedures or a service manual.

Correlation with C1931

• The presence of C1931 (abnormal leak of brake ACC pressure) strongly suggests hydraulic-pressure-related fault(s). Inspect for an internal brake-fluid leak and accumulator/pressure sensor integrity. In some OEM contexts, the "ACC" refers to the brake assist hydraulic circuit; leaks there can reduce pedal feel and ABS function.

Rule-out sequence (prioritized)

1) External leak identification and repairable leaks (lines, fittings, caliper/seal, master cylinder).

2) Master cylinder internal leak (often presents as low fluid with poor pedal feel; master cylinder replacement may be necessary).

3) ABS hydraulic control unit (HCU) leak or failure (replacement of HCU/ABS module if fluid source is internal).

4) ABS control module/electrical fault (module replacement or reprogramming as per OEM guidelines).

5) Wheel-speed sensors and wiring (repair or replacement as needed).

6) Repair approaches (based on findings)

• External leaks: replace/repair leaking hoses, fittings, or caliper seals; bleed system after repair.
• Master cylinder: replace the master cylinder if internal leakage is confirmed or pedal feel is spongy/low.
• ABS HCU: replace/repair the hydraulic control unit if internal leaks or failed valves are confirmed.
• ABS control module electrical fault: repair wiring, replace or reprogram the ABS module per OEM procedures; ensure compatibility with vehicle's CAN bus and any immobilizer/reconciliation requirements.
• Confirm that brake-fluid level and system pressure are restored to spec after repairs; perform a full system bleed if needed.

7) Post-repair verification

• Clear DTCs with the scan tool and re-check for any new codes after repair.
• Perform a controlled test drive (as safe as possible) to confirm brake pedal feel, ABS operation, and that warning lights do not reappear.
• Recheck brake-fluid level after a short test drive; ensure no residual leaks.
• Monitor ABS live data (wheel-speed sensors, modulator activity, and hydraulic pressure if available) to confirm normal operation.

8) Special notes for Prius or hybrid-brake contexts

• In the specific NHTSA case, a Prius V showed B2060 with C1931 and low brake fluid, raising concern for hydraulic leaks that can affect ABS behavior in hybrids. While the exact OEM interpretation of B2060 varies by platform, the linkage between ABS malfunction and brake-fluid/hydraulic issues is a key diagnostic cue in this scenario. OEM service information (TSBs) should be consulted for model-specific steps, as the Prius brake system includes hybrid-brake integration and energy recovery components that influence ABS behavior. Use OEM wiring diagrams and service procedures when diagnosing (as with any modern vehicle).

9) Diagnostics summary and probability framing (caveat: )

• Based on the single NHTSA report paired with B2060 and C1931, the leading cause is an internal hydraulic issue linked to brake-fluid loss (master cylinder or ABS HCU). Estimated qualitative probabilities (for planning purposes; not a substitute for OEM data):
  • Internal brake-fluid leak (master cylinder or ABS HCU): high likelihood (roughly 60-70%)
  • ABS pump/HCU fault or valve/solenoid issue: moderate likelihood (roughly 20-30%)
  • Electrical fault in ABS module or wiring (CAN/ground issues): lower likelihood in this dataset (roughly 10-20%)
  • External brake line/leak not readily visible: lower likelihood in the cited case but possible (roughly 5-10%)
• Note: The above percentages are indicative given only one NHTSA data point for B2060; actual OEM-reported distributions may differ. If more NHTSA or technician-reported cases are available, adjust the probability estimates accordingly.

10) References and where to look next

• NHTSA complaint example (ABS malfunction B2060, C1931 leak): demonstrates a real-world scenario where B2060 accompanied by brake-fluid loss suggests hydraulic/ABS interdependency. Use as an anchor for symptom-to-system reasoning.
• OBD-II diagnostic framework: general description of DTCs, including body codes (B) and the role of ABS-related codes within the OBD-II structure. Useful for understanding that B2060 is a body-code category and that its precise OEM meaning can vary.
• Code definitions: source for standard interpretations of DTCs and the expectation that OEM-specific definitions may vary; verify with OEM service information for the exact vehicle.

Final notes

• Always corroborate B2060 with other ABS/ braking-related codes and vehicle-specific service information. Because B2060 definitions vary by OEM and model year, OEM service data should be your definitive reference for exact fault descriptions and repair steps.

This diagnostic guide was generated using verified reference data:

• NHTSA Consumer Complaints: 1 real-world reports analyzed
• Wikipedia Technical Articles: OBD-II

Content synthesized from these sources to provide accurate, real-world diagnostic guidance.

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