Hello, I am trying to find the information on location and function of all the passenger compartment relays. All the ones in the engine bay are labeled, and all the fuses are labeled, but I cannot find any good information on the relays.

Background story: Was on a road trip and the car refused to start after stopping to fill up gas. Green Key indicator flashes on the dash, its the OE key and it does the same with the OE backup key. Dealership claimed the fuel pump was shot, and that I needed an entire new wiring harness. I inspected the fuel pump assembly myself and found the ground wire to the fuel pump had gotten hot enough to melt through the basket top. In-tank plug was melted and burnt. The plug connector on the harness side was discolored but not destroyed, thankfully. Ordered a new complete fuel pump basket, but the car still doesn't start. Let me clarify, it cranks, just not starting. The fuel pump never primes. The green key light continuously flashes on the dash. The ECU doesn't seem to be powering up. I verified this with a scan tool, which is unable to connect to the ECU and gives an alert that the Key is not turned on or the Power to the ECU is not present. I replaced the fuel pump relay when this all happened in the parking lot of the gas station I was stranded at. I have power everywhere else in the car, literally everything else is working. Any insight would be greatly appreciated.

 

Is your check engine light on when ignition on, engine off?

 

Yes, the CEL is illuminated.

 

SORRY for late reply
Looks like the overheating of fuel pump relay affected its ground circuit (provided by ECU and shared by immobilizer inside of it, this is why it does not recognize the key )
The FP relay is sealed (not solid state) located here (brown one)

Yellow arrow points to the FP relay. With ignition off , place a finger on it, and tun ignition on. You should feel a click under your finger.

Most likely there will be no click
Check the fuse #9 under dash box, column of fuses to the left of the relay, if melted replace and try to start an engine
if not starting go to the next step
Remove the relay (may need to use relay pliers, believe me it's tight!) and look on the of it
If it is NOT melted and the socket is in the good condition make a fused jumper (15 A fuse ) and jump two wide slots (this will Jerry rig the relay and supply power from ignition switch right to the pump). momentary turn the key on. If fuse does not blow turn key to crank and attempt to start an engine
If engine starts (which is a guess at this point),
1) We found a simple way to defeat immobilizer
2) we will troubleshoot the fuel pump control circuit next

 

PS also make sure there is continuity between fuel pump ground wire and a body!

 

I made a jumper yesterday and used it to trigger the fuel pump (blue), to verify the fuel pump circuit was intact, which it is. I just tried the jumper on the Main FI relay (brown), and the pump primed when I turned the key to ON. However the car still did not start. I still have a flashing Green Key on the dash, and with no start, I assume we still have an ignition/fuel injector cut going on. But, this feels like progress!

 

I made another jumper and placed it on the Blue Relay. So, both Brown and Blue are "hot", still no start, but, I can connect to the ECU with scan tool now. And, no trouble codes present.

 

Thanks for an update. Just to clarify, have you had jumper in place during cranking?
Visually inspect pins on the PCM as marked A2, A3 (red box) ,E17 relay coil input pin (green box) and E27 (immobilizer signal input), right under it



The cover panel under glove box must be removed to access these terminals

 

So, after being sidetracked the last hour or so, I made a third jumper and put it in the coil relay position, and now the car starts and runs. Am I looking at a triggering issue from the ECU, or three faulty relays?

 

Can you snap a picture with jumpers in place? Is green key still blinking on the cluster when engine runs>?

 

You may put two other relays back one a t the time and see if no start returns!

 

Yeah, I'll get a pic. No green key light at all with all three of the jumpers in place.

 

I did replace the coil relay with a known good equivalent, and it did not start.

 

This combination yields a starting car. So, main FI relay is working properly, fuel pump and coil relays are not getting triggered.

 

Sounds like a fuse # 14 in under dash box (same as relays)

 

What ended up fixing your fit? I’m in the exact same position. Looking like the multiplex fuse panel is the problem but figured I’d see what you ended up doing to fix yours! Thanks a lot!

This combination yields a starting car. So, main FI relay is working properly, fuel pump and coil relays are not getting triggered.

 

Can you do me a favor and try to start the car in the same combination using mechanical key (without chip)? If fuse I mentioned before is good and fuel pump relay is clicking the immobilizer may have some issues

 

Don’t think it’s an immobilizer issue.

 

sounds like my problem. did you get a resolution? was it your fuse box ?

 

So I will try this jumper method tomorrow. It's so weird everything has been working fine. Today I go to the storage and try to start the vehicle and cranks bit doesn't start. No leaks. Voltage at 13.4 and I used my Volt meter and at the fuel pump, I get 5.6 volts constant even when I try to crank the key over. So I'm assuming the relay isn't sending the full 12 volts to the pump cause I don't hear the pump either. I'll keep you all posted to what I find.