Damaged or corroded wheel speed sensor number four (often the right rear on Volkswagen models) or its connector; Debris, metal shavings, or rust buildup on the sensor tip or the tone ring, disturbing the magnetic signal; Wiring harness damage between the sensor and the ABS control module, such as chafing, water ingress, or a broken wire; Faulty ABS control module or TCM internal processing error, though this is less common; Excessive air gap between the sensor and the tone ring due to worn wheel bearing or damaged hub; Tone ring cracked, missing teeth, or contaminated with grease and dirt

DTC codes / Volkswagen codes / P1726

P1726 · VolkswagenWheel Speed Signal 4 Range Performance

Q: What does code P1726 mean?

Wheel Speed Signal 4 Range Performance. P1726 on Volkswagen vehicles means the transmission control module (TCM) has detected that the wheel speed signal from sensor number four is outside the expected range or performance window during a defined driving condition. The TCM compares this signal against the other wheel speed sensors and the vehicle speed, and it sets the code when the fourth sensor's signal is missing, erratic, or implausible for the current speed.

P1726 on Volkswagen vehicles means the transmission control module (TCM) has detected that the wheel speed signal from sensor number four is outside the expected range or performance window during a defined driving condition. The TCM compares this signal against the other wheel speed sensors and the vehicle speed, and it sets the code when the fourth sensor's signal is missing, erratic, or implausible for the current speed.

SystemPowertrain

Code typeVolkswagen specific

SeverityMedium

Fix difficultyIntermediate

AreaTransmission

Symptoms you may notice

Anti-lock braking system (ABS) warning light and traction control light illuminated on the dashboard
Transmission may enter limp mode or shift harshly because the TCM relies on wheel speed for shift scheduling
Speedometer may read incorrectly or fluctuate if the affected sensor is used for vehicle speed
Cruise control may stop working or disengage unexpectedly
Often no symptoms besides the warning light, especially if the fault is intermittent

Common causes, most likely first

Damaged or corroded wheel speed sensor number four (often the right rear on Volkswagen models) or its connector
Debris, metal shavings, or rust buildup on the sensor tip or the tone ring, disturbing the magnetic signal
Wiring harness damage between the sensor and the ABS control module, such as chafing, water ingress, or a broken wire
Faulty ABS control module or TCM internal processing error, though this is less common
Excessive air gap between the sensor and the tone ring due to worn wheel bearing or damaged hub
Tone ring cracked, missing teeth, or contaminated with grease and dirt

How to diagnose and fix it

Scan all modules for stored and pending codes, then record freeze-frame data for P1726 to see the conditions when it set
Visually inspect wheel speed sensor number four, its connector, and the tone ring for damage, debris, or corrosion, and clean as needed
Use a scan tool to view live wheel speed data for all four sensors while driving; compare sensor four to the others for dropouts or erratic readings
Measure the sensor's resistance and check the wiring continuity from the sensor connector to the ABS control module, repairing any open or short circuits
Check the air gap between the sensor and tone ring and inspect the wheel bearing for play that could affect the signal
If the sensor and wiring test good, substitute a known-good sensor or perform a scope test on the signal to confirm the fault before replacing the ABS module
After repair, clear codes and perform a road test to verify the code does not return and that ABS and traction control operate correctly

Why sensor four often misleads on Volkswagen

On many Volkswagen models, wheel speed sensor four is the right rear sensor, but the numbering can vary by platform, so always confirm the sensor location with a wiring diagram before ordering parts.
A common misdiagnosis is replacing the ABS control module when the real fault is a corroded connector or a chafed wire in the wheel well that only acts up over bumps or in wet weather.
Metal debris stuck to the magnetic encoder ring inside the wheel bearing can produce a plausible-looking but erratic signal that does not always set a sensor circuit code, so a visual inspection of the tone ring is essential.
The TCM uses wheel speed signals for shift quality and torque converter lockup, so a failing sensor four can cause transmission complaints that lead owners to suspect the gearbox rather than a wheel sensor.
Intermittent P1726 codes that appear only at certain speeds often trace to a wheel bearing with early-stage play that changes the air gap, not to the sensor itself.

Can I keep driving with P1726?

You can usually drive the vehicle to a workshop, but avoid relying on anti-lock braking or traction control and expect possible harsh shifting or limp mode. Do not tow heavy loads or drive at high speed until the fault is repaired, because the ABS and stability systems may be disabled.

Tools that help

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Guidance is general and written for Volkswagen vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.