krymarchuk
New member
- Joined
- Jul 4, 2010
- Location
- Langley, BC
Hey guys, I've just completed a bunch of stage 0 work on my (new-to-me) 1991 940 SE, and am getting faults codes 1-2-3 (socket 2) and 2-2-4 (socket 6), relating to a fault in the ECT sensor connection.
For a little background, here is my project thread that outlines the work I've done recently: https://forums.turbobricks.com/showthread.php?t=360385
I recently pulled the intake off, replacing heater hoses and the valve, throttle body gasket, intake manifold gasket, injector seals, etc. Of course, I decided to replace the ECT (the ECU/EZK sensor under #3 intake runner) since I had easy access. On reassembly of the fuel rail and manifold, I cleaned the grounds on the intake manifold/fuel rail bolts and used some ox-gard on them.
The new sensor was an aftermarket unit bought from IPD. When installing, I followed a Brickboard FAQ tip about using a thin coating of Ox-Gard on the sensor threads when installing into the block.
Old sensor removed:
New sensor installed:
With everything buttoned back together, it took a long while to start again...numerous cranking attempts and needing to give it some throttle to have it catch and run before it would settle into an idle. Once it runs for a minute or so it will hold an idle okay. Once up to temperature, it will fire up again without an issue, so it is struggling more so when cold. CEL same on, and throws codes 1-2-3 and 2-2-4 as mentioned above. I checked the connector to the ECT to make sure it was connected and seated, cleared the codes, and they come back after it is fired up again.
I've done a lot of searching and reading on the issue, and found numerous areas to look at for diagnosing whether it is a fault in the wiring or the sensor. First step, I decided to test the grounds.
I checked resistance between the manifold grounds (two ring terminals each, under both the forward and rear fuel rail/manifold bolts) and the battery negative terminal. Both read 0 ohms. Same with the grounds on the back of the valve cover to the firewall.
So then I pulled the ECT connector, and attempted to check resistance of the sensor pins to ground. No matter what I try, I'm getting an infinite reading on the pins...checked to both the manifold grounds, and the battery negative terminal.
So before going further, I'm looking for some feedback on what to do next. Given I can't get a resistance reading from the sensor pins, does this indicate a bad sensor or no grounding to the block? Do I focus on that first, without needing to check voltage or resistance back to the ECU and EZK pins?
Appreciate any help or support on this topic! As I said, I've done a lot of searching and come across a lot of info for diagnosing ECT issues, however a lot of the threads end up with at least some kind of resistance readings from the sensor and focus on the ECU pins and wiring/grounds.
For a little background, here is my project thread that outlines the work I've done recently: https://forums.turbobricks.com/showthread.php?t=360385
I recently pulled the intake off, replacing heater hoses and the valve, throttle body gasket, intake manifold gasket, injector seals, etc. Of course, I decided to replace the ECT (the ECU/EZK sensor under #3 intake runner) since I had easy access. On reassembly of the fuel rail and manifold, I cleaned the grounds on the intake manifold/fuel rail bolts and used some ox-gard on them.
The new sensor was an aftermarket unit bought from IPD. When installing, I followed a Brickboard FAQ tip about using a thin coating of Ox-Gard on the sensor threads when installing into the block.
Old sensor removed:
New sensor installed:
With everything buttoned back together, it took a long while to start again...numerous cranking attempts and needing to give it some throttle to have it catch and run before it would settle into an idle. Once it runs for a minute or so it will hold an idle okay. Once up to temperature, it will fire up again without an issue, so it is struggling more so when cold. CEL same on, and throws codes 1-2-3 and 2-2-4 as mentioned above. I checked the connector to the ECT to make sure it was connected and seated, cleared the codes, and they come back after it is fired up again.
I've done a lot of searching and reading on the issue, and found numerous areas to look at for diagnosing whether it is a fault in the wiring or the sensor. First step, I decided to test the grounds.
I checked resistance between the manifold grounds (two ring terminals each, under both the forward and rear fuel rail/manifold bolts) and the battery negative terminal. Both read 0 ohms. Same with the grounds on the back of the valve cover to the firewall.
So then I pulled the ECT connector, and attempted to check resistance of the sensor pins to ground. No matter what I try, I'm getting an infinite reading on the pins...checked to both the manifold grounds, and the battery negative terminal.
So before going further, I'm looking for some feedback on what to do next. Given I can't get a resistance reading from the sensor pins, does this indicate a bad sensor or no grounding to the block? Do I focus on that first, without needing to check voltage or resistance back to the ECU and EZK pins?
Appreciate any help or support on this topic! As I said, I've done a lot of searching and come across a lot of info for diagnosing ECT issues, however a lot of the threads end up with at least some kind of resistance readings from the sensor and focus on the ECU pins and wiring/grounds.