# Constant EPC light, unfixable?



## manny3118 (Nov 20, 2019)

Hey guys,

I drive a 2018 Tiguan SE with 40k miles which I've been happy with except for one thing--an undiagnosible EPC light. I first encountered the error on a road trip when it presented while I was on cruise control-- the engine ran rough a few seconds before it came on, the dash flashed a start/stop error screen, and I got a CEL + limp mode. It was a hot summer day, and assumed perhaps the car overheated-- so I key cycled the car after a few minutes, the codes disappeared, and drove off without issue. I scheduled an appointment with service, and they told me that unless the code was present during inspection, there was nothing they could do (big mistake). I took their word for it.

I then had the issue about 3 more times, all on hot days, which I also cleared by resetting the car-- once on a busy highway. I said enough is enough, and scheduled a new service appointment. Reluctantly, they diagnosed code P0203 and replaced the entire wiring harness and intake manifold. 

Problem solved right? Wrong. Same light appeared this weekend.

Anyone else have this issue?


----------



## smg64ct203 (Jan 26, 2003)

Last Saturday the epc light came on and went into the limp home mode. I shut the car off and it cleared but I took it to the dealer and we’re able to pull up codes that it stores even without the light. Last week my car started misfiring on the highway it does did it one day and no light on. I didn’t bother to take it in because no light on. 

They told me it needs a wire harness for the fuel injectors and it has a bad fuel injector. They ordered the parts but it’s not done yet.


----------



## zimmie2652 (Feb 15, 2015)

Most likely the injector itself if the wiring harness didn’t sort it out.


----------

