2004 TDI 1.9 BEW Power Issue

Update to this original problem below.

I have a BEW Engine Stock. I recently ran into a Problem.

Engine Light. Loss of Power. Barely accelerated when floored, and made it home, max 45 MPH.

Immediately Thought MAF Sensor. Unplugged it, power returned immediately. Ok, replaced with Bosch unit. Immediately back to original issue. No Power, very bad performance.

Pulled BEW EGR Valve, Clogged. Cleaned well and replaced. Plugged back in MAF sensor. Same issue. Intake is really clean for having 200,000 miles.

If I sit in car, Turn on Key only. There is a screaming (whining) noise under hood near ERG Valve. Squealing. Engine is not running. Just key on.

So If I plug in MAF Sensor with cleaned EGR Valve, Very Low power over 25 MPH, extreme struggle. Unplug MAF sensor, MAX power. Excellent speed. Will put you back in seat.

Codes Thrown are
P2413-Unsure of this one?
p0402-Exhaust Gas Recir flow
P0101-Range/performance
P0864-Circuit code

I appreciate the post from community. I have been doing a lot of research on this site. Re Posting in hopefully more appropriate area.

What I met by screaming is more of a whining? Electrical whining noise that is isolated to the ASV or Extremely near, and that only leaves EGR, ASV. Turn Key on and you hear the noise under hood. From ASV area. Car takes 3-4 Cycles to Start. On the 4th time it will start. If you plug in MAF sensor it starts first hit, but must unplug to drive over 20 mph. The whining will still remain for about 35 seconds after key is off. I have learned this may be the ASV Adjusting itself? But it is making movements with the valve inside if you pull the Boost hose. You can see valve turning back and forth, then shutting. Sound stops. I had a Boost leak, and purchased a Dog Collar from Kerma TDI to get that hose fixed. Can't find any Vacuum leaks?. Still running with plenty of power with No Plug on MAF Sensor. Turbo spins up well. The boost/Vacuum pump on right of engine had a loose hose connection, that was replaced. It still has some good pull for Vacuum. Would suck my pinky finger inside. But I don't have tools to gauge exact numbers. I love the car. And want it fixed. Would be happy to pay a Real "non-stealership" mechanic. But cannot find anyone to look at it.

Thanks for reading!

Is your car a stick or automatic? That was about the only piece of info you didn't state above.

Does anyone have VCDS near you? Get a scan and load up the log here.

Auto, Wish I could say 5 Speed. I live in sticks. I have words out to get a friend of a friend that can hook me up with VCDS. I hope I can.

For some reason Ross-Tech search for P0864 returns:
01315 - Transmission Control Module
01315 - Transmission Control Module: No Communications
Possible Causes
CAN-Databus Wiring/Connectors from/to Transmission Control Module faulty
Fault(s) stored in Transmission Control Module

For the P0101:
16485/P0101/000257 - Mass Air Flow Sensor (G70): Implausible Signal
Possible Symptoms
Loss of Power
Erratic Idle
Possible Causes
Mass Air Flow Sensor (G70) faulty
Air Leak(s) after Mass Air Flow Sensor (G70)
Excessive restrictions in the Intake/Exhaust System
Dirty air filter, clogged snow screen, clogged CAT
Ground Spots corroded or Paint Residue
Wiring and/or Connections from/to Mass Air Flow Sensor (G70) faulty

You cleaned the EGR & intake was OK.
The codes are spread through 3 different systems.
I'm thinking a bad ground (3 lines up) or bad wires / connections.
If the ground under the battery tray is bad anything that grounds to the body is bad.

sounds like you broke off your boost tube. where your intercooler attaches to the egr is prone to breaking, make sure its sealed well and no boost leaks

Mwheaty said:

sounds like you broke off your boost tube. where your intercooler attaches to the egr is prone to breaking, make sure its sealed well and no boost leaks

Click to expand...

If that was the issue, I would expect that disconnecting the MAF would make no difference.


I recall having similar symptoms with an ALH, and replacing the MAF was the ticket in that situation. YMMV