P2294 N276 problem

Fahrenheit_29 said:

No it came from New Jersey. Here's a link to the exact one I bought.
https://www.ebay.com/itm/333263767437

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OK, but that's clearly a Chinese Replacement Auto Part.

Important: We have three warehouses. Two in U.S. One in China. All listing list that U.S. Buyers ship from US, others ship from China

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-Uwe-

Alright well do you have a link to one that should be good for sure. Like not the most expensive one if possible

Have you simulated the circuit with a decade box back to ECU to authenticate the DTC will change as a result, instead of just tossing parts at it?


Please JPPSG the entire thread!
https://forums.ross-tech.com/showth...essional-Problem-Solver-Guide-quot-JPPSG-quot

I have not. Guess I need to buy one of those

Like this?

https://www.amazon.com/dp/B0002KX76W/ref=cm_sw_r_fm_apa_i_7WYuEbS227GDW

Lot less than another HPP huh?

And is the resistance supposed to be 25 to 35 ohms???

Read the factory book sir, RTFB is my advice.

Did you know you can change ranges of resistance & through circuit to reflect DTC changes or vacated static to see short to ground, open or short to B+?
Did you consider that the DTC you have in your scan is implying the circuit is incomplete being open?

Fahrenheit_29 said:

And is the resistance supposed to be 25 to 35 ohms???

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I have seen that value given in a few sources (erWIN, Bentley etc.) for the fuel pressure regulating valve N276 between pin 1 & 2 at 20°C but I do not think that it correct. Testing on a known working one I am seeing about 1.6 ohms between Pin 1&2. I have seen others test brand new Hpfp and are also showing about 1.6 ohms and also used ones. I would be looking at the wiring to & from Pin 1&2. Pin 1 is +12v from battery through relay & fuse.

Thanks. Both mine are showing 1.6 ohms. The wiring checks out continuity wise from ECU plug and also that relay. The resistance on both wires is .6 ohms and no shorts to ground. I though about replacing that relay but I know it functions for other sensors or solenoids and they all test out.
The pigtail from the harness to my n276 clip is a bit crusty but still snaps on and I can still get continuity through it. I'm going to replace it anyway even though I'm sure it's not the issue.
I think my next step mainly is to put the ECU back in and get everything hooked back up and start over in troubleshooting knowing the wiring looks ok. Who knows, maybe it will work again hahaha

Thanks. Both mine are showing 1.6 ohms. The wiring checks out continuity wise from ECU plug and also that relay. The resistance on both wires is .6 ohms and no shorts to ground. I though about replacing that relay but I know it functions for other sensors or solenoids and they all test out.
The pigtail from the harness to my n276 clip is a bit crusty but still snaps on and I can still get continuity through it. I'm going to replace it anyway even though I'm sure it's not the issue.
I think my next step mainly is to put the ECU back in and get everything hooked back up and start over in troubleshooting knowing the wiring looks ok. Who knows, maybe it will work again hahaha

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I wouldn't be so sure if yourself, did you know, continuity tests with DVOM, well.......are not tests for the ability to flow current?

Correct. I haven't load tested yet. I planned on that as well before assembly...

All my testing seems fine. About to try a decade box and see if the ECU reacts.

I put it back together and it's doing the same thing. If the decade box does not give me a result I guess I'm going to be out a ECU? Sucks

Explain how you conducted your wire tests, the equipment used and settings?

Did you try an overlay to test that theory too?

I pulled the ECU plug and ran a continuity test from the pin in the ECU plug to the pin on the n276 plug. I was using my elenco dmm. That same test yielded a .6 ohm resistance on the wire. Load tests with a light like in the video seem good as well. I did this on both wires. The second wire runs to a relay in the fuse box

An overlay test, do you mean new wires from each location to the plug? I did not.

I have a decade box on the way. Not sure what resistance to throw at it as the 25 to 35 ohms listed on a site, people have said may be wrong...I understand how the ECU reads a temp sensor, not really sure how that compares to the n276 as it's actuated by the ECU and not just referenced if I'm not mistaken. If that's the case I'm not sure how a decade box could help. I guess key on engine off testing it might do something if I could figure out the correct resistance.

I was told here that my hpfp I purchased on eBay is clearly an eBay third party part even though it's stamped Hitachi. I'm not happy with the fitment of it so I'm probably going to buy another one from a more reputable site and swap my internals into it. I'm wondering if the n276 in this cheap one i got might be bad or the wrong part, causing my problem.

One test I'm scared to do but might help is throwing 9 volts to the n276 while car is running and watching the fuel pressure at the rail to see if it will even build pressure. I know this can be dangerous because it could build too much pressure but it would be just for a split second and watching the graph.

Lastly I read somewhere that the module on the fuel tank can cause this too, since I can't actuate the n276 from VCDS I'm assuming that's not the case. Any input on this one would be cool.

Sorry for all the info but it's where I'm at with it. I understand wiring but when it comes to how all the systems work together in the car I'm still learning. I feel like if I can't actuate the n276 it can only be the sensor, wiring, or the ecu. I can actuate other solenoids and it uses the same relay so I don't think the relay is bad

An overlay test, do you mean new wires from each location to the plug? I did not.

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Yes.

I have a decade box on the way. Not sure what resistance to throw at it as the 25 to 35 ohms listed on a site, people have said may be wrong...I understand how the ECU reads a temp sensor, not really sure how that compares to the n276 as it's actuated by the ECU and not just referenced if I'm not mistaken. If that's the case I'm not sure how a decade box could help. I guess key on engine off testing it might do something if I could figure out the correct resistance.

I was told here that my hpfp I purchased on eBay is clearly an eBay third party part even though it's stamped Hitachi. I'm not happy with the fitment of it so I'm probably going to buy another one from a more reputable site and swap my internals into it. I'm wondering if the n276 in this cheap one i got might be bad or the wrong part, causing my problem.

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Did you do any search's of videos online or from FLUKE?

One test I'm scared to do but might help is throwing 9 volts to the n276 while car is running and watching the fuel pressure at the rail to see if it will even build pressure. I know this can be dangerous because it could build too much pressure but it would be just for a split second and watching the graph.

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Is this a test in the RTFB because decade boxes are indeed in the RTFB as a VAG/VAS device are they not?

Lastly I read somewhere that the module on the fuel tank can cause this too, since I can't actuate the n276 from VCDS I'm assuming that's not the case. Any input on this one would be cool.

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Heard? Did you check NHTSA and TSB's or TPI for service action or recalls yet?

Sorry for all the info but it's where I'm at with it. I understand wiring but when it comes to how all the systems work together in the car I'm still learning. I feel like if I can't actuate the n276 it can only be the sensor, wiring, or the ecu. I can actuate other solenoids and it uses the same relay so I don't think the relay is bad

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Yes this clear?







https://www.warwickts.com/4486/VAG-28mm-Automotive-Oscilloscope-Breakout-Lead-Set