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Installed rob tune ecu and codes 45 21 12

Posted: Sun Oct 22, 2017 3:17 pm
by oldbugeye
Hey guys I installed my robtune finally . It’s been years of dreaming of getting this far . Once the car is running it runs great but I am getting codes 12 21 45 code 12 is normal because the starter is wired to a hidden button i had a car stolen... but the codes 45 and 21 are new code 21 is coolant temp sensor and 45 is pressure sensor does it mean map? Anyway the car has a terrible time starting on a cold start it takes a couple minutes of trying . Once it’s running it runs great and on a warm start the cel goes away. So is there something I missed in the wiring convention ? I also did a coil over plug conversion at the same time . I didn’t mess with coolant temp wireing at all . And is code 45 the map sensor or boost control. It just says pressure sensor . I followed instructions from how to convert coil over plug thread viewtopic.php?f=19&t=53990 . It’s just weird that the coolant temp would fail at the same time as converting to robtune. Thanks for any help , also I just put it into d check mode and driving around the only code it flashes is 43 throttle switch . The coolant temp code and pressure sensor code do not flash.

Re: Installed rob tune ecu and codes 45 21 12

Posted: Thu Apr 12, 2018 7:08 pm
by Legacy777
Did you end up getting this resolved or are you still having the problems?

Re: Installed rob tune ecu and codes 45 21 12

Posted: Mon Apr 16, 2018 3:45 am
by pabst90-ix
Id like an update as well, I am literally dealing with those exact codes after my robtune install and a new swap.

Edit: I am not seeing 12... I am seeing 21 and 45.

Re: Installed rob tune ecu and codes 45 21 12

Posted: Mon Apr 16, 2018 4:33 pm
by ride_child
code 45 is your map sensor.
maybe they were stored codes in the ecu?

Re: Installed rob tune ecu and codes 45 21 12

Posted: Mon Apr 16, 2018 7:15 pm
by mike-tracy
Josh usually advises to start with the lowest number code and fix that first.

Re: Installed rob tune ecu and codes 45 21 12

Posted: Sat Apr 21, 2018 4:51 pm
by pabst90-ix
Isnt the map sensor bypassed with the rob tune? And im going to be adressing the temp sensor, its just a pain becauuse i just finished the build did intial start up and now i have to break it down again...

Also if the radiator fans cycle during system check does that signal the sensor is actually good and its a wiring issue?

Will i damage anything if i continue engine break in with a bad coolant sensor (fans running constantly) and a map sensor code?

Re: Installed rob tune ecu and codes 45 21 12

Posted: Mon Apr 23, 2018 6:42 pm
by Legacy777
When the ECU is in D-Check mode the fans will cycle. This allows you to test/check the relays. If the fans are cycling all that's telling you is the ECU is telling the fans to turn on and off, the wiring is good, the relays are working, and the fans are working.

With a bad coolant temp sensor you could be running richer or leaner. I would assume the default would be richer, which isn't necessarily better. I'd suggest starting with the coolant temp sensor and go from there.

Re: Installed rob tune ecu and codes 45 21 12

Posted: Wed May 16, 2018 5:21 am
by RckyMtnLegacy
Did this get resolved? I'm getting 43 as well with the green connectors along with 22, and 51

Re: Installed rob tune ecu and codes 45 21 12

Posted: Mon May 21, 2018 5:52 pm
by Legacy777
What do you get with just the black connectors?

Re: Installed rob tune ecu and codes 45 21 12

Posted: Mon May 21, 2018 6:35 pm
by RckyMtnLegacy
I'm getting nothing now after repairing shielded knock sensor connector

Re: Installed rob tune ecu and codes 45 21 12

Posted: Tue May 22, 2018 6:03 pm
by Legacy777
Ok, well that's good.

Re: Installed rob tune ecu and codes 45 21 12

Posted: Thu Nov 30, 2023 6:50 am
by sakis subaru
Code 45 subaru legasy ej 20 one turbo model 1993 ποιο ακριβώς είναι; οι 3. Sensor φαίνονται εντάξει η αντίσταση είναι οκ Δεν παίρνει μπροστά η ανάφλεξη καθόλου. Χαιρετισμούς από Ελλάς Μακεδονία

Re: Installed rob tune ecu and codes 45 21 12

Posted: Fri Dec 08, 2023 4:46 am
by wtdash
sakis subaru wrote: Thu Nov 30, 2023 6:50 am <Translated>Code 45 subaru legacy ej 20 one turbo model 1993 what exactly is it? the 3. Sensors look ok, the resistance is ok. The ignition does not come on at all. Greetings from Hellas Macedonia
Good day- Code 45 isn't your main issue (unless Greece cars have something different for their ECU programming???). It is something else. I saw your other post and car starts and shuts off. That's likely a fuel, ignition or air issue. Could also be camshaft or crankshaft sensor.
VERY likely there are other codes. If you're using the same Black Diagnostic connectors under the dash, ensure you're counting the blinking correctly.