Ground wire for fuel pump relay 2?

Hello, the ground does go through the ECM, the OEM diagrams are showing a transistor inside the ECM that closes that ground connection. So, either you have a wiring issue from the relay to the ECM, it's missing an ECM ground, and I will post the diagrams, or the transistor driver inside the ECM burned out. A wiring issue to the ECM is the most likely problem, so checking the wiring from the relay to the ECM would be my first test.
There are the connector C 108 at the Junction Block, also C 28 a connector in between the ECM and the junction block, and then the ECM connector itself.
The C28 connector looks like it's in a pretty difficult place, somewhere in the lower center console. So, checking the circuit from the relay to the ECM connector for an open circuit to begin with will be easier. I'll find the ECM pinout.

The transistor is what the ECM uses to turn that ground connections off or on. It's a 3 pin component, think of it like a switch, when the ECM sends a low voltage signal to the Base of the transistor, it turns the transistor on and completes the Ground through the other 2 pins. The 1st diagram is one I threw together to show how a NPN transistor works, the rest are the connections in between the relay and ECM and each connectors pinout. Just note that when you go to check the ECM connector to see if that ECM pin is making ground for the relay, you need to use an led test light, that ECM driver is not made for high current, if the transistor isn't bad and you use and incandescent test light to check that ECM ground you could burn it out. That Fuel pump relay probably only pulls 150 to 200ma maybe. So, anything more than that and the ECM will be junk. Using an LED test light is the only safe way to check that ECM driver. If you don't find any connection issues to the ECM, check the relays resistance, a shorted relay on its control side will burn out a driver like that. Relays are usually around 75 ohms.

As long as the key is off you should be okay, I assume you're back probing the ECM connector. You just don't want to draw current through the ECM to ground, so if you had the test light hooked up to battery positive and were checking that ECM pin to see if it was grounding, which would be pulling current through the ECM driver. LED test lights only pull about 20ma. But a regular test light can pull too much. When you were getting no ground, were you cranking the engine, because that relay is going to give a 2 second prime with key On, and then wait for the cranking to reenergize that circuit. It's kind of a bad design putting 2 fuel pump relays in there. Not sure why they need to do that. Also are you getting a crank signal from the Tach? Or do you have a scan tool where you can look for an rpm signal?

I know you're not hearing the pump, I'm just curious how are you checking for ground on the number 2 relay, are you using a test light to battery positive?
Oh goodness. One of those situations huh. So you're not sure what he may have done.

Okay, so you're checking from the relay to battery negative and aren't getting any ground at any point. And that original issue was no fuel pump operation when you got to it? The only reason I get super careful when it comes to ECM drivers, is some drivers have protection inside the ECM and some don't. And looking at these OEM diagrams I don't see any kind of resistor like I do on an ECM power feed. And even a multimeter puts out voltage to check resistance in a circuit. My main meter I use for continuity check puts out a very low voltage because it's a self-ranging meter but my other meter which is more basic puts out 2.4volts when doing a regular continuity check. I hope he didn't try jumping power on the fuel pump relays. Seeing you're the 2nd guy onto this, now it's difficult to say if he caused more damage. Did you bench test the relays just to see if they had continuity on the load side when powered up? Because if you don't have any ground at the ECM at this point, then doing powers and ground checks on the ECM is next. Sorry for the long post.

Oh okay, you don't even have the vehicle yet. I gotcha, I'm going through the ECM powers and grounds right now but will also try to find a better diagram of that connector in the center of the dash. I've seen a lot of electrical problems with these cars, did he give you any additional information on it?

Yeah, I do mobile diagnostics too, got to love it. Were there any codes stored? This C28 connector looks like it's below the HVAC controls, it has wiring for the cluster and control harness combination. So that's not very helpful.
Also, a 16pin dlc plus another data connector that's C30 pins 21 to 32, I don't know what this other data connector is for. Also found this through all data community, looks like there is supposed to be an empty space between the 2 fuel pump relays. This 3rd diagram will be helpful too.

One other quick test you can do is that pin at the ECM, pin 22 with key on should read 12-volts until the engine is cranked over and the relay is pulled to ground. So, Key on 12-volts, engine running less than 1 volt. 12-volts will travel through the relay to the ECM connector until the ECM grounds it. This will verify your powers through that hidden connector without having to deal with it. Looks like a black wire.

At the ECM? And the voltage doesn't drop off when cranking? If not, we need to figure out if there's any inputs missing to the ECM. I'd think it would just be a crank signal, but there might be an ignition feed missing since he had the fuses out. That's something that will need to be verified. I haven't gone through all the power feeds yet to the ECM, it's a bit slow with these OEM diagrams.

With the relay in, you should read 12v on pin 22 of the ECM. The wire that gets grounded. It will read voltage until it's pulled to ground by the computer. Same with a fuel injector, or any other solenoid. The control wire will read the voltage coming through the relay until the relay is energized. Once you start to crank the engine over, that voltage should drop to 0v.