2012 jerta tdi help

Got it — then we need to state that clearly and correctly so mechanics don’t dismiss the post. Here’s a revised Facebook post that reflects what VW told you and still keeps the diagnosis tight.

You can copy/paste this one 👇

---

2012 VW Jetta TDI CJAA — intermittent stalling / limp under load — need experienced TDI input

Looking for help from VW/TDI mechanics or anyone who’s dealt with this exact issue.

Vehicle

2012 VW Jetta TDI

CJAA engine

VIN-verified by VW parts dept

Symptoms

Starts and idles fine

Revs in park

Under load / acceleration:

Cuts power

Flashing glow plug light

Goes into limp mode

Turbo whistle present

Does NOT stall at idle

RPM does NOT drop to zero when the issue happens

Codes

Repeated P0321 / G28 – Engine speed signal implausible

VW dealer confirms that with this VIN, G28 corresponds to the CAMSHAFT position sensor, not crankshaft

What’s been done

In-tank lift pump replaced

Fuel filter replaced

MAF cleaned

Intake inspected

Turbo visually inspected

Fuel pressure does not drop to zero during events

What has NOT been done yet

Turbo actuator movement test (manual or vacuum)

N75 solenoid replacement

Camshaft position sensor replacement (waiting on confirmation)

Notes

Issue only occurs while driving / accelerating

Feels load or heat related

Trying to diagnose properly, not throw parts at it

Questions

1. Has anyone seen a failing camshaft position sensor (VIN-specific G28) cause limp mode only under load?

2. Can a turbo actuator or vacuum issue trigger a secondary engine speed plausibility fault like this?

3. Would you test turbo actuator/vacuum before replacing the cam sensor?

Any real-world CJAA experience appreciated.