by "DC3 LS, will be perpetually replacing cars until the end of time" (dc3ls-)
Published 12/19/2017 at 19:24
by "DC3 LS, will be perpetually replacing cars until the end of time" (dc3ls-)
Published 12/19/2017 at 19:24
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STARS: 2
(Me and AMGTech trying to calm the dumpster fire, colorized 2017)
So anyhoo. I got the connector and sensor to finally work together. However, the ECU is suppose to be sending 5V to the sensor, it’s only sending 3.5V. So the car still won’t run. Tomorrow I’ll test the voltage coming right out of the ECU. If it’s 5V then I have fucked up wiring somewhere, if it’s 3.5V, then hopefully it just means the ECU is bad and I can get a cheap one off ebay.
The wire from C26 to the temp sensor is the one with 3.5V.
"AMGtech - now with more recalls!" (amgtech)
12/19/2017 at 19:33, STARS: 1
C26 should be the reduced signal voltage. C18 should be 5v. But it looks like you’ve got a solid plan!
"Dr. Zoidberg - RIP Oppo" (thetomselleck)
12/19/2017 at 19:47, STARS: 2
How about jumping ship for another spooky project? :D
https://seattle.craigslist.org/sno/cto/d/lexus-ls/6382115683.html
"DC3 LS, will be perpetually replacing cars until the end of time" (dc3ls-)
12/19/2017 at 20:15, STARS: 0
It’s not even a project, it’s just a dd!
"DC3 LS, will be perpetually replacing cars until the end of time" (dc3ls-)
12/19/2017 at 20:16, STARS: 0
But the wire coming from C26 was the one with 3.5V with the sensor disconnected. I think the wire from C18 is a common ground with the other stuff. I could be wrong though.
"DC3 LS, will be perpetually replacing cars until the end of time" (dc3ls-)
12/19/2017 at 20:18, STARS: 0
Ohhhhh, I think that’s the problem. C26 has to be the reduced signal voltage, and the other one’s the hot wire. Otherwise the ECU would be reading the resistance of all the sensors. Or maybe that’s how it works? It’s like a checksum?
"DC3 LS, will be perpetually replacing cars until the end of time" (dc3ls-)
12/19/2017 at 20:30, STARS: 0
Ok I just double checked, and the pigtail on the connector is correct (so the wires to the connector aren’t switch.)
"FTTOHG Has Moved to https://opposite-lock.com" (alphaass)
12/19/2017 at 20:31, STARS: 1
I wouldn’t call it a checksum, but yes that’s how it works. C18 is a 5V supply to all of those other things on the line. The variable resistor at the coolant line drops the voltage and it is read as something less than 5V at C26. The voltage it reads is converted to a temperature. I just looked at the diagram quickly, but it looks like C18 is an output and C26 is an input to the ECU.
"DC3 LS, will be perpetually replacing cars until the end of time" (dc3ls-)
12/19/2017 at 20:41, STARS: 0
But I had 3.5V on the wire going to/from C26 and no voltage on the one going to/from C18.... I took those readings with the sensor disconnected, so the two wires weren’t connected.
"AMGtech - now with more recalls!" (amgtech)
12/19/2017 at 21:03, STARS: 1
In this instance, things can backfeed or the ECU might substitute an estimated value. I wouldn’t worry too much about that. With the sensor connected and key in position 2/run, do you have 5v from C18? If not, every sensor fed by C18 will be down.
"DC3 LS, will be perpetually replacing cars until the end of time" (dc3ls-)
12/19/2017 at 21:04, STARS: 0
I haven’t checked with the sensor connected, I’ll do that tomorrow though.
"AMGtech - now with more recalls!" (amgtech)
12/19/2017 at 21:06, STARS: 2
I also suspect there are more sensors fed by this than what this diagram shows. Or by a different pin on the ECU that sends out a 5v ref. Possibly like cam and crank position, which could definitely cause a no start.
"FTTOHG Has Moved to https://opposite-lock.com" (alphaass)
12/19/2017 at 21:32, STARS: 0
Like AMGTech said, it doesn’t really make any sense to read that line without a resistor on it - it’s an input.