C0173 code meaning
Right Rear ABS Outlet Solenoid Circuit Malfunction
What C0173 means
No accessible J2012 list, maker index or NHTSA bulletin contains C0173, so the code cannot be tied to any vehicle; Saab, for instance, reports a fault in either valve of the right rear wheel as C2485. By its title it covers the release valve of the right rear brake. In the Saab hydraulic unit this valve is closed at rest and opens, together with the return pump, only when that wheel nears lock-up, letting fluid out of the caliper into a small accumulator. Saab energises every valve for 20 ms in a self-test at each key-on and switches ABS, traction and stability control off when one fails. An outlet coil that cannot open leaves the rear wheel prone to locking during ABS braking; a leaking one lets the caliper lose pressure.
C0173 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyHard
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of C0173
- ABS and brake warning lamps on, ABS/TCS/ESC switched off
- Right rear wheel may lock under hard braking
Common causes of C0173
- Most likelyOpen or shorted coil of the right rear outlet valve
- PossibleCorroded or loose contact between valve block and control module
- Less likelyFaulty valve driver stage inside the control module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
ABS hydraulic unitABS control moduleSolenoid valve
What each part of C0173 means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 73 | The exact fault in that area. |
What to do next
- Note C0173 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 C0173
What does C0173 mean?
C0173 means "Right Rear ABS Outlet Solenoid Circuit Malfunction". No accessible J2012 list, maker index or NHTSA bulletin contains C0173, so the code cannot be tied to any vehicle; Saab, for instance, reports a fault in either valve of the right rear wheel as C2485. It is a generic code, so it means the same on every make.
Is it safe to drive with C0173?
Drive gently and only to a workshop. With C0173 the car can go into limp mode (reduced power) to protect itself.
Will C0173 fail an emissions test?
C0173 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 C0173 to fix?
Difficulty: hard. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will C0173 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.