ECM Power Relay J271?

[04blackout]

Cruising on the interstate today at typical highway speed and I felt a couple sputters. About 10 seconds later I felt like power was fading so I got over to the shoulder. I tried to crank it and it felt like it wanted to go and would fire up for a split second and then just die. I have a spare coil pack in the trunk at all times so I tried all of them, no dice. While I waited for the tow truck I read a bunch of posts on fuel pump, fuel pump relay and ECM power relay.

When I got home I yanked out the fuel pump relay and swapped it out with one from AutoZone around the corner. No dice. I hooked up the laptop and got the following codes:

17536 - Fuel Trim; Bank 1 (Mult)
P1128 - 001 - System too Lean
17769 - Cylinder 3 Ignition Circuit
P1361 - 004 - Open Circuit
17772 - Cylinder 4 Ignition Circuit
P1364 - 004 - Open Circuit
17645 - Fuel Injector for Cylinder 1 (N30)
P1237 - 004 - Open Circuit - Intermittent
17647 - Fuel Injector for Cylinder 3 (N32)
P1239 - 004 - Open Circuit - Intermittent
17648 - Fuel Injector for Cylinder 4 (N33)
P1240 - 004 - Open Circuit - Intermittent
17646 - Fuel Injector for Cylinder 2 (N31)
P1238 - 004 - Open Circuit - Intermittent
17072 - ECM Power Relay Load Circuit
P0688 - 004 - Open Circuit - Intermittent

In looking around it seemed like the ECM power relay could be the culprit so I pulled it out. Until the dealership opens tomorrow and I can go grab a new one, I hooked it up to the multimeter. On 200 Ohm range, I get a reading of about 63 Ohm on the control circut and as best as I can tell from the Google, that's within an acceptable range of 50-120, albeit on the low side. When I powered the control circuit, I heard a click (good) but measured slight resistance from 30-87 and 30-87a (3 and 6 Ohm, respectively).

One other observation: when I finally got out there and yanked the ECM power relay, it had been about 6 hours since the car was running. I did try to crank it a couple times before pulling it but it seemed warm to me, relative to the ECM and other relays next to it.

Odds that this thing is cooked?

[Anthony23]

had same issue had to redo my injector wiring take alook at that and see how it looks

Sent from my SM-N950U using Audizine mobile app

[old guy]

Sounds like a short in the injector harness. Have you checked your engine management fuses? There are four engine management fuses. 29, 32, 34 and 43.

[04blackout]

Thanks for the reply!

Yes, I should have mentioned that - when I was sitting there I had enough spare fuses in the glove box where I swapped em all out, both one at a time and at one point I had all new ones in there for anything labeled fuel and engine management.

Would a short in the injector harness also cause the P0688?

One more piece to this puzzle: I left my lights on at work the other day (first time ever!). When I got out to my car I feel like I heard this clicking noise under the hood somewhere near the firewall. I jumped it and never thought of it until just now.

[SO WAGN]

Are you using stock or aftermarket injectors? In the past I’ve had intermittent issues with the EV14 adapters. I burnt through a number of fuses until I figured out what it was. I would also suspect the injector harness being the cause of the issue.

[04blackout]

Are you using stock or aftermarket injectors? In the past I’ve had intermittent issues with the EV14 adapters. I burnt through a number of fuses until I figured out what it was. I would also suspect the injector harness being the cause of the issue.

All stock. The weird thing to me is that in all of my reading in this area the #29 fuse is usually blown whereas I’m OK there.

On the other hand, y’all have consensus so I’m gonna go check the injector harness this morning. I also wonder if I broke the coil harness trying to swap out coils; I’ll give that a look too. Learning here, but I guess if all these components share a 12V in the main harness to the relay, a short could impact multiple components. Thanks!

[SO WAGN]

Let us know how it goes. It’s common for a single short to result in numerous fault codes, although it often is due to a blown fuse.

[04blackout]

Let us know how it goes. ItÂ’s common for a single short to result in numerous fault codes, although it often is due to a blown fuse.

Injector harness connector on 4 was flaky on the 12V wire, so I replaced the connector. It started right up which was cool because I could get it out of my street and up my sloped driveway into my garage. It died right in front of the overhead door. Back to it...

[04blackout]

I had noticed I didnt hear any fuel pump priming sounds since it happened. I just ran jumper cables back to the pump, hooked + to the pin that connects to brown and - to the opposite pin. The pump didn’t make any noise. Also, when I push the end of the fuel rail a little drips out but no pressure.

Is this pump my culprit?

At the very least I am the owner of two new injector connectors and one ignition connector.

[Turbo510]

I would expect, but don't know for sure, that the brown wire at the pump connector is ground. Verify that by Ohming between bare body metal and the brown wire's connector - should be close to zero Ohms.

You spent more effort than you needed to, for instance, swapping a new coil pack was useless since a failed one doesn't keep the engine from running at all.

Next, the fuel pump check should first consist of knowing whether or not you have power available to run it. I simply disconnect the pump harness connector, then jumper it to a standard 55W headlight bulb. Crank the engine, and if it lights, but otherwise the pump doesn't run, then pump failure is likely. Next, use that Ohmmeter to check motor resistance between the terminals on the white plastic tank top: if open circuit, the motor is dead.

Lastly, my 3.0 was giving me some fits some time ago, in that case causing stumbles and low power, plus engine speed sensor codes. I found that my ECU relay was barely making contact between one pair of points inside. After cleaning the contact surfaces, plus giving the Brass contact lever a slight adjustment, no further problems.

[04blackout]

I would expect, but don't know for sure, that the brown wire at the pump connector is ground. Verify that by Ohming between bare body metal and the brown wire's connector - should be close to zero Ohms.

You spent more effort than you needed to, for instance, swapping a new coil pack was useless since a failed one doesn't keep the engine from running at all.

Next, the fuel pump check should first consist of knowing whether or not you have power available to run it. I simply disconnect the pump harness connector, then jumper it to a standard 55W headlight bulb. Crank the engine, and if it lights, but otherwise the pump doesn't run, then pump failure is likely. Next, use that Ohmmeter to check motor resistance between the terminals on the white plastic tank top: if open circuit, the motor is dead.

Lastly, my 3.0 was giving me some fits some time ago, in that case causing stumbles and low power, plus engine speed sensor codes. I found that my ECU relay was barely making contact between one pair of points inside. After cleaning the contact surfaces, plus giving the Brass contact lever a slight adjustment, no further problems.

I stumbled upon a thread where diagnosticator and old guy laid it out pretty clearly and in my haste I read the wrong reply. You’re right, it’s not the brown one, it should be the green/yellow.

Oh well, I got a job I had to get back to so I had it towed to a garage. My first time in 15 years sending it in somewhere for an SOS. I’ll report back.

[SO WAGN]

Eeeesh, a busy 24hrs you've had mate!

I've had to run a dedicated line (fused, relayed off stock pump harness) to my Walbro pump. I was getting low fuel pressure on high boost and when I tested the stock wiring to the pump I was only getting 10.5v!
Because of the car having a bit of downtime and you've probably been cranking it a bit to see if it'll start and the battery might be low. It would be worthwhile ensuring you've got a battery jumper just in case you've got low voltage on cranking. If you're still on the stock fuel pump it should power up but higher output pumps definitely require stable power.

[04blackout]

For sure it was a long period!

Garage just called and the fuel pump is dead. Will confirm for sure when it’s driving down the road tomorrow and report back.

I’m wondering if all those intermittent codes were truly intermittent (after all, those frayed wires didn’t just fray a couple days ago).

Thanks for all your help guys - cheers!

[Turbo510]

So the second fuel pump is dead? The one from AutoZone? Maybe, but hopefully that shop knows how to prove the pump is bad, and is honest.

[04blackout]

I never changed the pump myself, only tried swapping a fuel pump relay from Autozone

[Turbo510]

OK, I mis-read your post. So hopefully the new pump solves it.

[04blackout]

The fuel pump it was! When I picked it up I was BSing with the guy at the shop. I said something to the effect of I must have had two issues at once. He said "probably, it's an Audi!"

I guess I got lucky, probably for a while, with those open circuit codes. But at the end of the day I did clean up a bunch of frayed wires which would have only degraded even more over time, so that's a win.

Thanks again to the folks here - I read through a lot of posts from you guys that helped me solve and diagnose both issues.

[Turbo510]

That's good news!

[SO WAGN]

Nice work! Glad to hear it's sorted. Thanks for posting back the outcome. It's always good to have these threads closed out with a solution for those that stumble across them in the future.

Yeah it's a good thing you have sorted out the wiring at the same time. It's one of those things that could potentially leave you stranded if there's an intermittent short. The potential is even worse for anything fuelling related if it's causing a sustained lean condition.

Have fun with the car now that it's back on the road.