CEL: 252 Tank Ventilation System

[m_dudey]

Hey guys,

So I've completed my swap and the engine is running pretty smooth. Specs below:


-stock s52 converted to OBD1
-getrag 260 tranny
-m50 manifold
-obd1 exhaust manifolds and midpipe
-3.5" bosch MAF
-TRM off the shelf chip for the above mods


Problem is that I keep getting a check engine light when I rev it pass 3k rpms or so. I have carsoft and scan the code in the DME and I get

252 Tank Ventilation System

-Cleared the CEL.
-Fire up the engine, no CEL. Scan for codes, no codes.
-Rev it up to 3k rpms or so, CEL comes on.
-Scan for code and get the above code.
-Turn off car.
-Turn the key to ON position but do not fire up the car. Scan for codes, no codes.
-Fire up the car again, CEL is still on. Scan for codes, same 252 code.


It only detects this code when the car is fired up and running. If I don't fire up the engine and just have the key in the ON position, then it doesn't detect the code.

I've tried replacing the charcoal canister purge valve with a different one, still no luck. I've tried checking for vacuum leaks with carb cleaner but nothing noticeable, especially around the charcoal canister area and the throttle body housing.

Any other ideas guys?

[atldohc]

Hey guys,

So I've completed my swap and the engine is running pretty smooth. Specs below:


-stock s52 converted to OBD1
-getrag 260 tranny
-m50 manifold
-obd1 exhaust manifolds and midpipe
-3.5" bosch MAF
-TRM off the shelf chip for the above mods


Problem is that I keep getting a check engine light when I rev it pass 3k rpms or so. I have carsoft and scan the code in the DME and I get



-Cleared the CEL.
-Fire up the engine, no CEL. Scan for codes, no codes.
-Rev it up to 3k rpms or so, CEL comes on.
-Scan for code and get the above code.
-Turn off car.
-Turn the key to ON position but do not fire up the car. Scan for codes, no codes.
-Fire up the car again, CEL is still on. Scan for codes, same 252 code.


It only detects this code when the car is fired up and running. If I don't fire up the engine and just have the key in the ON position, then it doesn't detect the code.

I've tried replacing the charcoal canister purge valve with a different one, still no luck. I've tried checking for vacuum leaks with carb cleaner but nothing noticeable, especially around the charcoal canister area and the throttle body housing.

Any other ideas guys?

perhaps you could try the stomp test and see if you get a similar code:

http://www.troublecodes.net/bmw/

i have a similar setup to yours and when i swapped it i had a code 1263. which sounds like its equivalent to your troublecode. this was only because i didnt have the canister or solenoid hooked up at the time. when i plugged in the evap solenoid the code never came back. and at the time i didnt have the lines hooked up to the tb either. just had a vacuum cap on the tb to seal off any vacuum leaks. so it shouldnt matter with the 413 dme if theres any vacuum leaks etc. just that you have a working solenoid thats connected properly. its unlikely that you have two bad solenoids, but you could check the resistance with a multimeter to see if they are in spec. i believe the resistance is supposed be somewhere around 40-50 ohms. you can also try to see if they ever click when the key is turned on. if the solenoids are ok then i would start checking the electrical connector and wiring to the dme

[matt]

Yep, I would suggest checking the wiring and possibly trying a different DME.

[m_dudey]

okay, I did the stomp test. threw out code 1225, which according to the pelican parts website list of codes

http://www.pelicanparts.com/bmw/tech...de_reading.htm

is knock sensor #1

guess my carsoft wasn't able to read that.

anyways, how do I know if knock sensor #1 is the knock sensor for cyl 1-3 or 4-6? damn! either way, it's going to be a bitch to get to!

[matt]

1 is the front 3 cylinders.

[m_dudey]

How come when I do the stomp test, it flashes the code 1225, and then doesn't stop with a solid CEL? Instead, it keeps repeating thet 1225. All the instructions say that it will show a solid CEL after the codes are done flashing.

I'm just wondering if I have more codes that I'm not reading correctly.

[m_dudey]

replaced the knock sensor for cylinders 1-3. cleared the codes. started her up and revved it up. no CEL!!! shut her off and did the stomp test, no more 1225 knock sensor fault.

though when I use carsoft to scan for codes through the 20-pin, I still get a tank ventilation system fault code.

at least no more CEL on, whoohoo!

[atldohc]

glad to see you got it sorted it. perhaps there is a glitch with your carsoft. in any case i would trust whatever codes the dme is actually displaying. if it blinks the 1444 then it doesnt detect any malfunctions. but im sure you know that by now =)

[m_dudey]

yup! I only get 1444!