C0669 code meaning
Right Rear Wheel Speed Sensor B Circuit High
What C0669 means
With C0669 the second right rear speed channel shows a level above the valid range, which usually means it is connected to a voltage source it should not see. No carmaker publishes this code. Sensor chips are built to survive such faults for a while: NXP builds the input die of the KMI25 with a process rated for high voltage, precisely to shield the measuring parts from the harsh conditions on the supply line. For the older KMI15 NXP recommends extra parts against voltage spikes and reverse polarity and notes that many vehicle networks already cap load-dump surges at about 40 V. The brake module, however, will not accept the reading and shuts the channel off until the short to battery, the damaged lead or the faulty sensor has been dealt with.
C0669 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of C0669
- Warning lamp right after switching on
- Channel B switched off, assistance functions reduced
Common causes of C0669
- Most likelySignal lead shorted to battery voltage
- PossibleRepaired or replacement harness wired to the wrong pins
- Less likelySensor B shorted internally
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Rr wss bSensor wiring
What each part of C0669 means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 69 | The exact fault in that area. |
What to do next
- Note C0669 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about C0669
What does C0669 mean?
C0669 means "Right Rear Wheel Speed Sensor B Circuit High". With C0669 the second right rear speed channel shows a level above the valid range, which usually means it is connected to a voltage source it should not see. It is a generic code, so it means the same on every make.
Is it safe to drive with C0669?
Drive gently and only to a workshop. With C0669 the car can go into limp mode (reduced power) to protect itself.
Will C0669 fail an emissions test?
C0669 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is C0669 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. This is a job for a workshop.
Will C0669 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.