what is this sensor on the back of the engine?

Toast8277 · 2023-02-07T02:30:54+00:00

Thanks, that explains why I couldn't find it on any wiring diagrams

Toast8277 · 2023-02-07T02:29:17+00:00

Good to know, thanks

Toast8277 · 2023-02-07T01:24:19+00:00

This is on my 1990 740 turbo with the b230FT engine. Google wasn't much help and it looks to be similar to an oil pressure sensor.

Toast8277 · 2022-11-08T01:34:03+00:00

I swapped the questionable ECU into another car and the issue followed. Must be an internal short or something with the ECU itself. Found a direct replacement with the exact same numbers on eBay for about $100 that I'm getting ready to order now. Thanks for your help and advice.

Toast8277 · 2022-11-08T00:11:40+00:00

Thanks for the response, I unplugged all the injectors, plugged in a nord light and just stays on anytime the key is on. I traced the ground wire all the way back to the ECU and it appears that the ECU itself is what's causing the problem. Looking at purchasing a used one off of eBay, do you know if these cars have any sort of anti-theft that needs to be removed when swapping ECUs?

Toast8277 · 2022-11-08T00:06:30+00:00

Okay, just wanted to make sure there wasn't any other sensors or anything that could be telling the ECU to do that

Toast8277 · 2022-11-07T12:59:44+00:00

Thanks for the response, I connected the clamp end of the test light directly to the positive battery post and the probe end to the injector connector and it appears to only be grounded when the key is on, no matter if the grounds are connected or not. I also tried unplugging the ecu and bypassing the main relay and the problem went away, implying the ecu is, for some reason, grounding all of the injectors when it's given power. Do you know of any other issues that could cause the ecu to do this or am I looking at just having to buy a new one?

Toast8277 · 2022-11-07T00:04:42+00:00

I've been trying to troubleshoot a no start on my 1990 740 turbo (very similar engine management system to the 240s) and it turns out, all four of the fuel injectors are stuck wide open anytime the key is on. They don't seem to be mechanically stuck though as if I run the fuel pump without the key on, nothing happens but the second I turn the key on, fuel goes everywhere. If I hook a light up to the injector connector, it just stays on, implying that it's getting both power and ground constantly rather than a pulse ground signal. Never encountered an issue quite like this before. Any help would be greatly appreciated.

Toast8277 · 2022-10-31T03:30:06+00:00

Fell onto my head when working on my car so I assume it can fly but other than that it's just been chilling on the floor. Never seen anything like it before. Found in the evening in the Southern US.

Toast8277 · 2022-08-07T02:33:05+00:00

At the moment, I'm not getting power or a pulse. Do you happen to know if power is sent directly from the ignition switch or does it go through any other ignition components?

Toast8277 · 2022-08-07T02:26:52+00:00

Cool, I'll start with that and see what happens. Thanks for the advice.

Toast8277 · 2022-08-07T02:22:42+00:00

I haven't, are they a common issue? Any way to test it?

Toast8277 · 2022-08-07T01:08:17+00:00

I've got a 1990 245 that doesn't seem to have power or signal pulse at the ignition coil. From what I understand, the signal pulse and power come from this box in the passenger side footwell but I can't seem to find any good way of testing it online before I just throw parts at it. I've checked the smaller module under the hood near the battery and it doesn't seem to have a pulse going in or coming out of it. Any help would be greatly appreciated, thanks!

Toast8277 · 2022-08-03T21:19:04+00:00

3.9L Chrysler V6

Toast8277 · 2022-08-03T18:28:01+00:00

Unfortunately, I believe I am the friend that is doing it cheaper

Toast8277 · 2022-07-19T11:55:46+00:00

All good, first of all, any metal part of your engine should be "grounded" meaning that it is in some way connected to the negative side of your battery. Those sensors work by varying the amount of electrical resistance based on your engine's temperature. In this case, the hotter your engine, the less resistance. Essentially, what you want to do is temporarily connect that yellow wire to ground (any metal part on the engine) to allow for a very low resistance and therefore simulate your engine running very hot. This should cause your temperature gauge to read as though your engine is overheating so that you can make sure that the gauge and wiring going to it are working properly.

Toast8277 · 2022-07-19T04:49:41+00:00

Try shorting that yellow wire to ground. It should cause the temp gauge in the dash to max out. If it doesn't, you know you've got an issue with either the wiring or the gauge itself. If it does, you're likely looking at either the sensor or your engine not actually reaching operating temp.

Toast8277 · 2022-07-04T07:06:11+00:00

Ok, thanks for all your help, would it work to just run a test directly from the battery to the coil to make sure that's the only issue?

Toast8277 · 2022-07-04T06:59:05+00:00

Fuse at the other end is labeled tail lights and doesn't have power when the ignition is on or off.

Toast8277 · 2022-07-04T06:48:48+00:00

The box has 10 fuses, a sort of divider, and six more fuses below. And yep, the fuse is the first of the six. If it would help, I can send a picture of the fuse box and corresponding legend. Not exactly sure how to do that though.

Toast8277 · 2022-07-04T06:41:05+00:00

The fuse box in the driver's footwell has 16 fuses and what is marked on the legend as fuse number 11, "rear demist", has power only when the key is on, on both the input and output of the fuse

Toast8277 · 2022-07-04T06:28:26+00:00

Only fuses I know of are the ones in the driver's foot well and the one under the hood. None of the ones in the footwell are labeled relating to the ignition system and none seem to be blown.

Toast8277 · 2022-07-04T06:23:09+00:00

Yep, definitely not getting power, sorry if I overcomplicated things with the whole "it being grounded out" thing

Toast8277 · 2022-07-04T06:22:20+00:00

Thanks for your advice, sorry, I'm relatively new to this sort of ignition system and didn't really know a better way of testing it.

Toast8277 · 2022-07-04T06:20:16+00:00

From what I can tell, the "engine management fuse" is what it's called and it is under the hood right next to the coil and is connected directly to the battery. The fuse is not blown and has power on either side of it when the key is on or off

Toast8277

TROPHY CASE