C0040: Right rear wheel speed sensor circuit
What the code tells you on its own
- System
- Chassis
- Functional group
- ABS, brakes and stability
- Failure type byte, when the tool sends one
- 04 (System internal failure)
Braking, ABS/ESP, steering, suspension and wheel-speed sensing.
Scan tools report the same fault as C0040 and as C0040xx, where xx is a sub-type. They are one fault, and whether the sub-type appears at all depends on the tool and the protocol rather than on the car.
Diagnostics
What we see when C0040 turns up
Measured across the diagnostics run through Wrenchlane, not taken from a reference table. Figures as of 2026-10-06.
- Diagnostics
- 1
- Separate workshops
- 1
- Arrived code only
- 0%
- Most common marque
- Volvo
July 2026
Seen at a single shop so far
No symptom description entered at all
Where we have seen it most
These are counts from our own work, not a claim about how common the fault is across all vehicles. They describe what independent workshops brought to us, which is a narrower and more specific thing.
ABS, brakes and stability
Other abs, brakes and stability codes
- C0037 Left rear wheel speed sensor circuit
- C0031 Left front wheel speed sensor circuit
- C0034 Right front wheel speed sensor circuit
- C0061 Not individually documented
- C0050 Not individually documented
- C0035 Not individually documented
- C003A Not individually documented
- C0045 Not individually documented
FAQ
Frequently asked questions
How do I run a diagnosis?
Select the vehicle on Start, click the Diagnostic card and choose New diagnostic. Fill in the description, the error codes and the mileage, then click Analyze.
Do I have to type the codes from my scan tool?
No. Click the camera button next to Error codes and take or choose a photo of the scan tool's screen; WrenchLane reads the codes and their descriptions into the form. You can also speak them with the microphone.
Are the public fault code pages built from my diagnostics?
They use diagnostics run in WrenchLane, with no workshop, customer, registration number or VIN shown. Each fault code page shows how often the code was seen and in how many workshops.
Run C0040 against the car in front of you
Enter the code and the symptoms and get ranked probable causes for that specific vehicle, with the checks in the order worth doing them. Free account, no card.