Diagnostic article Generic OBD-II
P2C90: Wagoneer ventilation hose code with MUA and PCV valve branches
P2C90 is the crankcase-ventilation hose A disconnected code in this application.
Read before applying this article
Documented application
FCA bulletin 09-010-23 Rev. A, June 2023: 2023 Wagoneer and Grand Wagoneer WS with 3.0 L EFH twin-turbo engine, built before June 22, 2023, in the bulletin’s North America and MEA markets.
The code alone does not identify a failed part or establish that a vehicle is safe to drive. Confirm the vehicle, reporting module and applicable service procedure.
A hose-disconnected message can involve a valve
P2C90 is the crankcase-ventilation hose A disconnected code in this application. FCA identifies an undersized make-up-air check-valve spring and gives different repair paths according to production date and test results. The description therefore does not prove that a hose is visibly detached. Establish the engine and build date before substituting a general vacuum-leak repair for this manufacturer case.
Production date changes the next step
For vehicles built before March 6, 2023, the revision directs replacement of the MUA check valve. Later builds enter a controlled warm-engine inspection. That test requires coolant above 80 °C, specified air-conditioning settings, a shutdown interval and a brief controlled transmission-load sequence before reading P2C90. Those conditions make an incidental cold-idle scan an inadequate substitute. Because the procedure includes holding the vehicle in drive, it belongs in a properly equipped workshop rather than an improvised owner test.
The repeat-test branch has an explicit stopping point
If the specified inspection produces P2C90, the bulletin calls for PCV-valve replacement and repeat testing, with no more than three PCV replacements under that procedure. A continuing fault after the third requires normal diagnosis. Ask the shop to record which build-date branch applies, whether the code appeared during the prescribed test and each result after replacement. The document’s cap is significant: it does not authorize indefinite parts swapping. Current part selection, eligibility and any superseding instruction should be verified before applying this historical repair.
Source and applicability
FCA bulletin 09-010-23 Rev. A, June 2023: 2023 Wagoneer and Grand Wagoneer WS with 3.0 L EFH twin-turbo engine, built before June 22, 2023, in the bulletin’s North America and MEA markets.
Manufacturer bulletin, page 1 · Manufacturer bulletin, page 2 · Manufacturer bulletin, page 3
Article source documents
Source checks describe how the text was prepared; they do not certify a diagnosis or confirm compatibility with every vehicle using this code.
Original code reference
Dictionary definition
Crankcase Ventilation System - Hose A Disconnected
This definition retains its original catalog scope. The article above is limited to its explicitly documented application.
Reference scope
Generic OBD-II definition.
A manufacturer label does not establish the model, year, engine or module to which a diagnosis applies. Read the safety and diagnostic limits.
Definition source
- DTC Database: pinned community code definitions
Source checked · MIT