P2519 code meaning
A/C Request A Circuit
What P2519 means
P2519 covers the general circuit fault of a wired input through which the climate control asks the engine module for compressor operation. The engine module needs this request early, to raise idle speed, add torque reserve and then energise the compressor clutch relay. CARB therefore demands monitoring of electronic A/C components wherever switching the A/C changes fuel or ignition control, phased in from 2006 to 2008. Many current cars carry the request over CAN instead – Saab's 2011 9-5 is an example, with the HVAC module sending it as a message – and then network faults appear as U-codes rather than P2519. No maker documents P2519 publicly. P2520 and P2521 name a low or high level on the same input, P2522 the second input B. Expect A/C that does not start.
P2519 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2519
- A/C compressor never engages
- Idle speed does not rise when A/C is selected
Common causes of P2519
- Most likelyRequest wire broken or connector loose
- PossibleClimate control unit or A/C switch not sending a valid signal
- Less likelyEngine module input stage faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Ac request input aHvac module
What each part of P2519 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 5 | Area: vehicle speed, idle control and auxiliary inputs. |
| 19 | The exact fault in that area. |
What to do next
- Note P2519 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 P2519
What does P2519 mean?
P2519 means "A/C Request A Circuit". P2519 covers the general circuit fault of a wired input through which the climate control asks the engine module for compressor operation. It is a generic code, so it means the same on every make.
Is it safe to drive with P2519?
P2519 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will P2519 fail an emissions test?
P2519 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 P2519 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. This is a job for a workshop.
Will P2519 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.