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Just replaced ECT becasue truck was throwing a 21 code. Still showing code after installing new sensor. I reset ecm by unpluging battery terminals for 15 min. Truck seems to be stuck in cold mode or something. Code reader is also saying code 13,21,41,22,31. After truck warms up has rough idle, blows a lot of black smoke when giving gas and the exhaust smell burns the eyes terrible. I checked the voltage to the ECT harness and got 4.62v and on ground I’m getting 0.020. Could this be a wire issue or ecm issue ?
Ps forgot to mention I replace thermostat with 195f. All that seems to be working properly coolant wise gauge does read alittle past normal but I’ve been told them old gauge aren’t 100% accurate. Truck is a 1986 F150 302
Since you have all those codes, I would say it's a wiring issue. What voltage do you get when you measure between the 5v line and the return line or ground line, not a metal ground?
Just replaced ECT becasue truck was throwing a 21 code. Still showing code after installing new sensor. I reset ecm by unpluging battery terminals for 15 min. Truck seems to be stuck in cold mode or something. Code reader is also saying code 13,21,41,22,31. After truck warms up has rough idle, blows a lot of black smoke when giving gas and the exhaust smell burns the eyes terrible. I checked the voltage to the ECT harness and got 4.62v and on ground I’m getting 0.020. Could this be a wire issue or ecm issue ?
Ps forgot to mention I replace thermostat with 195f. All that seems to be working properly coolant wise gauge does read alittle past normal but I’ve been told them old gauge aren’t 100% accurate. Truck is a 1986 F150 302
Begin with the numerically-lowest error number, address that and only that issue, and then pull the codes again.
The link you have at the bottom looks like it’s for GM and says code 13 is o2 sensor. Everything I see says code 13 is for IAC. Should I start there anyway?
Hey Franklin 2 when I measure between 5v signal wire and ground wire I get 4.65v unplugged.
when I measure wires plugged in I get 3.58v
does this sound right?
I had to go back to the book to see what it says about this. They said the first thing to check is the 5v reference signal to the throttle position sensor. If it's no good (we know that it is not) and then go back to the computer and check it there with everything still plugged in. If it's not 5v coming out of the computer, the computer may be bad. Here's a diagram of it.
Looks like 5v is pin 26, negative is pin 46. See if you can poke those wires while they are still plugged in. Pin 26 is orange/white and pin 46 is black/white.
So I done some testing today on the ECT. After running for 25 min the voltage on the sensor was 1.45v. Shouldn’t it be lower than this? Also I checked other sensors and they are all receiving 5v(TPS,MAP). The ECT only reading 4.65v. Haven’t poked wires on ecm yet but did do a visual inspection on ecm itself and board looks super clean and no signs of corrosion or burnouts. Wondering if it could possibly be just a new BAD sensor 🤷🏻♂️
You can unplug the temp sensor and take a ohm reading on it. The guy in the book has a chart with approximate ohm readings at different temperature. He said it doesn't need to be exactly these numbers, but should be in the neighborhood.
Exchanged sensor for a new one and seems to be working now. Now gonna tackle code 22 MAP sensor out of range.its a new map sensor🤦🏻♂️. And also instead of code 41 I now have code 42 says running rich. Wish me luck
