SAE J2012-DA defines Diagnostic Trouble Code structure and provides standardized wording; C0706 is a chassis-level flag that points to a wheel-speed-related signal being implausible or inconsistent with expected behavior. The code does not identify a single failed part or a specific wheel/corner on its own and interpretation frequently varies by make, model, and year. You must verify with basic electrical and network testing — check sensor supply and ground, measure the speed signal with a scope or frequency meter, and confirm Controller Area Network (CAN) traffic for conflicting or missing speed messages before replacing components.
What Does C0706 Mean?
This article follows SAE J2012 formatting; the SAE J2012-DA digital annex publishes the standardized DTC descriptions and structure used here. C0706 is shown without a hyphen FTB (Failure Type Byte) in this guide. If a hyphen suffix were present, it would act as an FTB that narrows the failure type or sub-condition (for example, indicating short/high/low or intermittent behavior) while the base code still denotes the same system-level issue.
There is no single universal component-level definition for C0706 across all manufacturers. The code identifies a plausibility or performance problem with a wheel-speed-related signal used by chassis control systems. That distinction matters: C0706 signifies the signal does not make sense to the controller (out-of-range, inconsistent, or contradictory), not necessarily that a single sensor or module is definitively failed.
Quick Reference
- System-level meaning: chassis wheel speed signal plausibility
- Commonly affected systems: Anti-lock Braking System (ABS), stability/traction control
- Primary tests: scan tool live data, oscilloscope waveform, digital multimeter (DMM), CAN bus monitor
- Typical symptoms: ABS/stability warning, inconsistent speed readout, degraded traction control
- Interpretation varies by make/model — always confirm with electrical and network tests
Real-World Example / Field Notes
In practice you’ll often see C0706 logged when a controller receives a speed value that contradicts other sensors or time-based expectations. A common workshop pattern is intermittent faults after water intrusion; a connector that looks fine can have corrosion on terminals causing high resistance or intermittent open circuits. In that case, live data may show one wheel speed dropping to zero or producing noisy, jittery values while others remain steady — a plausibility failure rather than an absolute short.
Another field note: damaged tone rings or missing teeth are commonly associated with implausible waveforms. On vehicles with reluctor or hall sensors you might observe distorted or missing teeth with an oscilloscope; that waveform shape check is far more diagnostic than replacing a sensor without measurement. Always compare the waveform to the expected pattern for that sensor type.
Network issues can mimic sensor problems. A corrupted or missing message on the Controller Area Network (CAN) can make a module report implausible speed data even though the sensor and wiring test good. Use a CAN bus monitor to verify messages, message frequency, and whether multiple modules report consistent speed values. If CAN frames are inconsistent or absent, follow network troubleshooting before condemning the sensor.
Finally, simple power/ground faults and connector damage are often overlooked. Back-probe the sensor connector and check supply voltage and ground integrity while actuating the wheel or rotating the hub. Wiggle tests at the connector or harness can reproduce intermittent faults and are often the quickest way to confirm an intermittent open or poor contact; once reproduced, secure the connector or repair the wiring and re-test to validate the repair.
C0706 is a chassis-level Diagnostic Trouble Code (DTC) that points to an implausible wheel speed signal reported to a vehicle stability or brake control system. SAE J2012 defines the DTC structure and standardized wording, but many chassis codes do not map to a single universal component—interpretation can vary by make, model, and year. Treat this code as a symptom: inconsistent or non‑plausible speed data from one or more sources. You should confirm the fault with electrical and network tests before replacing any parts.
What Does C0706 Mean?
This explanation follows SAE J2012 formatting; standardized DTC descriptions are published in the SAE J2012-DA digital annex. C0706 is shown here without a hyphen Failure Type Byte (FTB). If an FTB were present (for example C0706-1A), it would act as a subtype that narrows the failure mode (like short, open, intermittent, or implausible pattern) while the base code meaning remains the same.
The code indicates a plausibility or correlation failure related to wheel speed signals as seen by a chassis control module (ABS/ESC/Traction). That means the module detected a speed value or pattern that conflicts with expected behavior or with other speed inputs. Exact interpretation and which module stores C0706 can vary by vehicle; confirm with targeted electrical and CAN/LIN testing rather than assuming a single failed sensor or location.
Quick Reference
- System: chassis wheel speed signal plausibility for ABS/ESC/traction systems
- Typical symptom: ABS/ESC light with irregular speed readings
- First checks: power, ground, connector condition, harness continuity
- Use tools: multimeter, oscilloscope, scan tool with live data and Mode 06, CAN bus monitor
- Diagnosis focus: signal waveform plausibility and network message consistency
- Repair emphasis: wiring/connectors first; module only after external inputs test good
Real-World Example / Field Notes
Shop experience shows C0706 frequently appears after a wheel bearing job where the tone ring is damaged or the sensor was reinstalled slightly out of position. One possible cause is a distorted tone ring that creates an irregular waveform; with an oscilloscope you’ll see missing or non-uniform pulses instead of a clean, repeating pattern. That waveform check is definitive for sensor/tone‑ring plausibility and far more useful than swapping parts blindly.
Corroded connectors and high-resistance grounds are commonly associated with intermittent or low-amplitude signals that trigger plausibility checks. In one case a customer had sporadic loss of speed on one channel in live data; back-probing the sensor connector while rotating the hub showed the supply sagging under movement, indicating a poor ground in the harness. A simple contact clean and re‑seating fixed the fault.
Network issues can mimic sensor faults. A missing or delayed Controller Area Network (CAN) message makes a module report conflicting speed values even when the local sensor waveform is fine. Use a CAN monitor to confirm message frequency and cross-check which modules report the same wheel speeds. If multiple modules disagree, suspect a bus-level problem before replacing sensors.
Wiring harness damage at common flex points is a frequent field failure: chafed insulation or a wire broken under the loom can cause intermittent opens only when the suspension cycles. Wiggle tests while watching live speed data often reproduce the fault. When you see noisy, jittery, or one-off implausible spikes on live data, capture an oscilloscope trace and compare it to a known-good pattern for that sensor type to prove plausibility issues.
Finally, note that sensor-to-module mismatches after module replacement or programming can create logic-level implausibility even if the physical sensor is fine. Confirm supply voltage, ground integrity, and raw sensor waveform at the connector first; only after all external inputs test good should you consider possible internal processing or input-stage issues in a control module.
Symptoms of C0706
- ABS light illuminated on the dash and steady or flashing during key-on or driving
- Traction control intervention or reduced traction/ESC activity when accelerating or on low-grip surfaces
- Brake feel change such as pulsation or perceived uneven braking under ABS activation
- Inconsistent speed readings between speedometer/cluster and scan tool data or a single wheel showing implausible rpm
- Stored fault in the braking network with related freeze-frame or Mode 06 data showing out-of-range values
- Intermittent faults that clear after a drive cycle but return under vibration or wet conditions
Common Causes of C0706
Most Common Causes
- Damaged or corroded wiring harness or connector pins at a wheel speed sensor — commonly associated with open, high-resistance, or intermittent connections.
- Faulty wheel speed sensor element or tone ring contamination/damage — one possible cause when sensor voltage/waveform is implausible during a controlled spin test.
- Poor power or ground to the Anti-lock Braking System (ABS) sensor circuit or control module — often seen when multiple wheel readings are affected or when voltage tests show out-of-spec supply.
- Network message loss or implausible data on the Controller Area Network (CAN) segment carrying wheel speed data — commonly associated with bus disturbances, module sleep/wake faults, or grounding issues.
Less Common Causes
- Internal input-stage issue in the ABS Electronic Control Unit (ECU) after all external wiring, power, and signal tests pass — possible only following thorough external verification.
- Intermittent short to battery or ground elsewhere in the chassis wiring harness that only appears under load or movement.
- Mechanical damage to the tone ring (missing teeth, deformation) that creates an irregular waveform only at certain speeds.
Diagnosis: Step-by-Step Guide
Tools: diagnostic scan tool with ABS/ESC live data, digital multimeter, lab-grade oscilloscope (preferred), backprobe set or breakout box, wiring diagram and pinlist, insulated jumper wires, wiring harness manipulator (wiggle tool), non-contact voltage tester, flashlight and cleaning supplies.
- Connect the scan tool and read live wheel speed data for all wheels. Note any wheel that shows zero, erratic, or implausible RPM compared with vehicle speed.
- Check freeze-frame and Mode 06 data for the fault to capture the conditions when C0706 set. Record vehicle speed, ignition state, and any related network errors.
- Visually inspect harnesses and connectors at the wheels and ABS module for corrosion, water entry, crushed wires, or bent pins. Tug and wiggle harness while monitoring live data for intermittent changes.
- Backprobe the suspect sensor connector with the key on and wheel stationary. Measure reference voltage/supply, signal, and ground with a multimeter. Compare to OEM expected ranges; if out of range, isolate power/ground before replacing sensor.
- If supply voltages are present, use an oscilloscope to capture the sensor waveform while an assistant rotates the wheel. Look for a clean sine/square wave with consistent amplitude and tooth count; missing pulses indicate tone ring or sensor problems.
- Perform continuity and resistance checks from the sensor connector to the ABS module pins using the wiring diagram. Look for opens, high resistance, or short to chassis/battery. Repair wiring faults before changing components.
- Check CAN bus health: measure bus voltages and termination resistance, and scan for network communication errors. If wheel speed messages are missing at the receiving module, trace the bus segment and connectors.
- After repairs, clear codes and road-test while monitoring live data to confirm the fault does not return and that wheel speed readings are plausible across speeds.
- If all external wiring, sensor waveform, supply, and CAN messages test good but the code persists, consider a targeted module input-stage fault only after documenting all prior good tests.
- Document test results, repairs, and re-check for intermittent behavior over several drive cycles or in different environmental conditions (wet/dry, vibration).
Professional tip: Always confirm a suspect sensor with a live waveform or controlled spin test before replacing it. Many failures blamed on sensors are wiring, connector, or tone-ring issues that will reoccur if you skip signal-level verification.
Possible Fixes & Repair Costs
Low cost fixes usually involve wiring or connector repairs when testing shows intermittent continuity, damaged insulation, or poor terminal contact. Typical fixes include cleaning and securing connectors, repairing a short or open in the sensor/signal harness, or replacing a blown fuse discovered during power/ground checks. Higher-cost repairs occur when a component like a pressure sensor, wheel speed sensor, or ABS modulator requires replacement, or when a control module requires reprogramming or replacement after all external inputs test good.
- Low: $50–$150 — justified when continuity checks, wiggle tests, and connector inspections locate a loose pin, corrosion, or a blown fuse and the sensor/module tests normal.
- Typical: $200–$600 — justified when bench-testing or in-situ signal waveform checks show a failed sensor or actuator that needs replacement, or when a harness splice must be professionally repaired.
- High: $700–$1,800+ — justified when diagnostics confirm a module internal processing or input-stage issue after power, ground, and network checks pass, or when labor-intensive unit replacement and programming are required.
Factors affecting cost: diagnosis time (labour), parts availability, need for specialized tools or programming, and vehicle-specific access. Always document voltage, resistance, and waveform test results before ordering parts. Replace or program a module only after confirming wiring, power, ground, and network messages are within specification.
Can I Still Drive With C0706?
You can often drive short distances with C0706 present, but your safe course depends on symptom severity. If braking feel, pedal response, ABS, or stability control behavior is affected, stop driving and tow the vehicle. If the code appears without any drivability or safety system degradation, you can drive to a shop while monitoring behavior, but prioritize electrical and network checks to confirm whether a critical sensor or communication failure is developing.
What Happens If You Ignore C0706?
Ignoring C0706 can allow an intermittent electrical or network fault to worsen, potentially degrading ABS or related chassis safety systems. Intermittent wiring or connector faults may escalate into complete loss of a critical signal, increasing stopping distance or disabling stability functions under emergency maneuvers.
Related Codes
- C0767 – Brake Control Signal Plausibility (Chassis)
- C0766 – Tire Pressure Monitor System – High Tire Pressure
- C0765 – Wheel Speed Sensor Signal Plausibility - Chassis
- C0764 – Tire Pressure Monitor System – Low Tire Pressure (Right Rear)
- C0763 – Steering Sensor Signal Plausibility
- C0762 – Brake Pressure Signal Plausibility
- C0761 – Brake Pressure Signal Plausibility
- C0759 – Steering Assist Communication Fault
- C0758 – Tire Pressure Monitor Sensor Circuit Range/Performance
- C0757 – Steering Angle Signal Circuit Fault
Key Takeaways
- SAE J2012-DA defines the DTC structure; C0706 is a chassis-level signal plausibility or circuit fault and may vary by make/model/year.
- Test-driven diagnosis is required: check power, ground, wiring/connectors, sensor plausibility, and CAN/LIN messages before replacing modules.
- Module replacement is justified only after all external inputs and network communications check good and confirm internal unit fault.
- Costs range widely; start with inexpensive wiring fixes and escalate only based on measured failures.
Vehicles Commonly Affected by C0706
Faults like C0706 are commonly seen on vehicles from manufacturers with advanced ABS/ESC integration and multiplexed networks, such as Audi, BMW, and some Ford platforms. They are often reported where brake pressure sensors, wheel speed sensors, and ABS modules communicate over CAN or LIN networks; complex architecture increases the chance that wiring, grounding, or network message timing issues trigger plausibility faults.
FAQ
Can I clear the code and drive without diagnosing?
Clearing the code temporarily may turn off the dash indicator, but it doesn’t fix the underlying fault. If the issue is wiring or an intermittent sensor, the code is likely to return. Always perform basic tests — battery voltage, ground integrity, connector inspection, and a quick CAN bus scan — so you can determine whether the fault is transient or requires repair before extended driving.
Can a bad ground cause C0706?
Yes. A high-resistance or intermittent ground can create false sensor voltages and implausible signals that trigger C0706. Use a multimeter to check chassis and module grounds under load, perform wiggle tests on harness grounds, and inspect grounding points for corrosion or loose hardware. If grounding measurements improve and the code clears, the repair is justified by those test results.
Is module replacement common for this code?
Module replacement is not the first step. It becomes a consideration only after you verify power, ground, sensor signals, wiring continuity, and CAN/LIN message integrity. If all external inputs and network communication are within specification and diagnostics point to internal processing or input-stage faults, replacement or repair of the module may be justified, documented by failing oscilloscope or bench tests.
How do I confirm a sensor is implausible?
Confirm implausibility by comparing measured sensor voltage, resistance, and waveform to known-good values or expected behavior during tests. Use a multimeter and oscilloscope for dynamic checks while exercising the system. If the sensor’s waveform or magnitude contradicts vehicle speed, pressure, or related signals and wiring is good, the sensor is likely the cause and replacement is supported by those measurements.
Should I expect other systems to be affected?
Yes, because chassis sensors often feed multiple systems like ABS, Traction Control (TCS), and Electronic Stability Control (ESC). A signal plausibility fault can disable or limit those features. Use a scan tool to monitor live data and CAN messages; if related modules stop receiving valid signals, prioritize fixing the electrical or communication cause to restore full system functionality.