[andydasmith]

I get this fault on my 1999 T4 on VCS. Engine runs rough, pickup is slow, idle surges, fuel consumption is high so I think it's correct. It appears that the pressure sensor is located in the ECU. I've searched the forum but cannot see if this is correct. There's a small diameter pipe running from the inlet manifold to the top of the firewall/bulkhead where I think the ECU must be located. Can anyone confirm that the manifold pressure sensor is inside the ECU?
The fault code is: 00519 - Intake Manifold Pressure Sensor (G71)
03-00 - No Signal
I've checked the pipe and there are no leaks.
Its a 2.0L AAC engine with a Tickfords gas conversion (no MAF). Fault is the same on petrol or gas, pickup is slightly worse on gas as you would expect
I'm hoping that I can avoid replacing the ECU, guessing that it will be expensive?

 

[gills]

Yes, intake pressure sensor is in the ECU. There's a small bore vac pipe which goes from the right of the inlet manifold (as you look at it) to the fuel pressure regulator and the ECU (located on inside of nearside inner wing - to the right of the battery). The pipe is very prone to perishing, which results in poor running. I would check/replace the pipe first (3.5mm for VW stuff, try here: http://www.justkampers.com/shop/vacu...re-j10558.html or 3mm silicon stuff is stretchy enough to fit http://www.ebay.co.uk/itm/3mm-x-3M-B...item3a49965d4f) and see if symptoms/error persists. Replacing an old/damaged pipe may well fix the problem and is a lot cheaper than a replacement ECU/ECU rebuild.

 

[andydasmith]

Thanks for the advice, I've found the ECU and checked the pipe. It seems sound but has a fluid, probably oil, in it's u bend. I'll replace it anyway (and clear the fault for a test drive) before I remove the ECU. The only other post I have found describes reading the pressure sensor on block 8/10 in Vag-Com. This may be incorrect for my ECU as this block does not return pressure readings.

 

[andydasmith]

Posting this in the hope that it will help someone else. I replaced the pipe to to ECU and that cleared the fault while stationary. Went for a drive and the pickup was a little better but the ECU reported the fault again when I returned. Removed the ECU (unlocking plug is tricky - you have to slide the plastic lock towards the front) and desoldered the pressure transducer to test with 5v. Sucked pipe and middle pin voltage moved so all ok. Soldered it back in and cleaned all the connector pins. I then cut a few tie-wraps that allowed me to replace the pipe that runs from a t-piece to the fuel pressure sensor (behind the rocker box). This is in the line to the MAP so I should have done it in the first place. Went for a drive and all good (acceleration now normal), no faults reported. Running is slightly better with petrol than gas but that may be normal. Seems that the only problem was perished pipes.

 

[gills]

Glad to hear you got it sorted, well doneT: