C1810

Code

Generic C — Chassis

ABS/Traction Control System Fault

Brand: Generic

Type: C — Chassis

Views: UK: 14 EN: 18 RU: 19

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Faulty wheel speed sensor(s)
Damaged tone ring/reluctor wheel
Open/shorted wiring or poor connector connection to ABS sensors or module
Blown fuse or failed ABS/traction control relay
Low battery voltage or poor chassis/power ground
Faulty ABS hydraulic unit or pump motor

Symptoms

ABS warning lamp and/or traction control/ESP/stability lamp illuminated
ABS/traction control interventions disabled or unavailable
Vehicle speed or ABS wheel speed readings erratic or missing in scan tool
Brake pedal pulsation absent during braking where ABS would normally activate
Unusual noises from ABS pump when activated (may be absent if pump dead)
Reduced vehicle stability control functionality

What to check

Read and record all stored ABS and network codes with a capable scan tool; record freeze frame and live data
Verify battery voltage at rest and under cranking; inspect battery condition and terminals
Inspect ABS fuses and relays related to ABS module and pump
Visually inspect wheel speed sensor connectors, wiring harnesses, and tone rings for damage, debris or corrosion
Check for CAN/network-related U-codes and verify module presence on network with scan tool
Measure resistance and/or AC output of each wheel speed sensor per manufacturer spec

Signal parameters

Wheel speed sensor: resistance (passive) — compare to manufacturer spec; AC voltage/frequency proportional to wheel speed when wheel rotated
Active sensor: reference/supply voltage (typically 5V) and signal voltage swing (check live data)
ABS module supply voltage: battery voltage at module pins while key ON/engine running
Ground circuit: low ohm continuity to chassis ground
CAN/vehicle network: module appears on bus; CAN high/low voltages and message traffic present
ABS pump motor current draw when commanded (compare to service limits)

Diagnostic algorithm

Use a professional scan tool to read all ABS and network codes; record freeze-frame data and live wheel speed inputs.
Clear codes, perform a short test drive while monitoring live wheel speed sensors, and recheck for reoccurrence.
Confirm battery voltage (12.4–12.8V resting, >13.5V charging) and test charging system; replace or charge battery if weak.
Inspect fuses/relays for ABS and replace if faulty; verify power reaches ABS module pins with key ON.
Visually inspect wheel speed sensor wiring, connectors, and tone rings for damage or contamination; clean or repair as needed.
Test each wheel speed sensor: measure resistance for passive sensors and check AC output while rotating wheel; for active sensors, verify reference voltage and signal waveform with scan tool or scope.
Wiggle harnesses and connectors while watching live data to find intermittent faults.
Check module grounds for corrosion and ensure low-resistance connections to chassis/negative battery terminal.
Verify CAN bus communication: confirm ABS module is present on network and that other modules report expected messages; repair network faults if found.
Command ABS pump and valves with scan tool and verify operation and current draw; replace hydraulic unit if internal faults are confirmed.
If wiring, sensors, fuses, relays and hydraulic unit check good and communications are intact, follow manufacturer procedure for ABS module diagnosis — module replacement may require coding/programming and should be confirmed last.
After repairs, clear codes and perform final road test to confirm system returns to normal and no new codes set.

Likely causes

Intermittent or broken wheel speed sensor signal (corrosion, damage, debris)
Corroded or loose connector at ABS module or sensor
Missing or damaged tone ring (cracked, missing teeth, heavy rust)
Low system voltage or weak battery under load
Blown fuse or failed relay supplying ABS module or pump
Open or high resistance ground to ABS module

Fault status

⚠️ Status

ABS/Traction Control Fault stored in ABS control module. Possible sensor, wiring, power/ground, hydraulic unit, or communication failure. ABS/traction functions may be disabled.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1-3 hours