P2679 code meaning
Coolant Degassing Valve Control Circuit Low
Powertrain system Generic code P26xx codes Check engine light
What P2679 means
P2679 indicates that the control line of the switched valve in the coolant vent path to the expansion tank reads too low. Usually the wire is grounded somewhere, or the solenoid has shorted turns; with a low-side driver the valve may then stay energised regardless of the command. The engine controller compares the line voltage with the state it set. Dodge lists P2679 among the fault codes that the reprogrammed engine controller of the 2004–2006 Sprinter can newly store under emissions recall T21, but the recall text gives no description of the circuit. Otherwise no maker explains P2679 publicly. CARB requires such circuit checks for controlled cooling components. A valve held in one state can slow warm-up or hinder venting.
P2679 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2679
- Check engine light or stored code
- Slow warm-up
- Coolant level fluctuations in the expansion tank
Common causes of P2679
- Most likelyControl wire shorted to ground
- PossibleShorted turns in the degassing valve solenoid
- Less likelyCoolant or water leaking into the valve connector
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Coolant degassing valveSolenoidWiring harness
What each part of P2679 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 6 | Area: computer (engine control module) and output circuits. |
| 79 | The exact fault in that area. |
What to do next
- Note P2679 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 P2679
What does P2679 mean?
P2679 means "Coolant Degassing Valve Control Circuit Low". P2679 indicates that the control line of the switched valve in the coolant vent path to the expansion tank reads too low. It is a generic code, so it means the same on every make.
Is it safe to drive with P2679?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2679 fail an emissions test?
Yes, it can. P2679 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2679 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P2679 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.