Dualxeon64 Posted August 19, 2020 Report Share Posted August 19, 2020 I get the following errors when trying to connect to my link ECU. Only reason i found i could not connect was because the car would not start. with the key on and confirmed power to ECU i get error unable to connect to the ecu. please check taht the ecu is properly connecteed, the power is turned on and teh correct com port has been selected. With the key turned off i get Unable to connect to the ecu but usb connection is present. please cycle the power to the ecu. I was able to connect last October when i got the ECU but then took my engine out to put a new full built motor. Wiring has not really change at all other than adding a electric boost controller. The injectors went from low impedance to high impedance but other than those 2 things all else stayed the same. Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 19, 2020 Report Share Posted August 19, 2020 If you pull the cover off the ECU, do you have a blue light glowing on top to show it is powered up? If you go to windows device manager do you have the ECU listed under COM ports like my example below? Quote Link to comment Share on other sites More sharing options...
Dualxeon64 Posted August 19, 2020 Author Report Share Posted August 19, 2020 I do not get a blue light at the board. When I use a volt meter I do get power to the ecu. I made sure com ports matched also tried baud rates as well. But to respond yes in device manager it lists as link. I actually removed then reinstalled the drivers as well. Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 19, 2020 Report Share Posted August 19, 2020 4 minutes ago, Dualxeon64 said: I do not get a blue light at the board. When I use a volt meter I do get power to the ecu. I cant remember if it was a blue or green light on the G4+, but it is obvious when they are powered up, you wouldnt miss it. So it sounds like it is not powered up... What ecu do you have - TST185+ or TST205+? So I can tell you where to check for power and ground. Quote Link to comment Share on other sites More sharing options...
Dualxeon64 Posted August 19, 2020 Author Report Share Posted August 19, 2020 Tst185 and yeah if there was a light I would notice it on. Quote Link to comment Share on other sites More sharing options...
Dualxeon64 Posted August 19, 2020 Author Report Share Posted August 19, 2020 I checked pins 71 +14v and 46 ground and I have power. Could my ecu be bad from sitting? I bought it brand new in October. Tested it and had no issues but pulled in from the car while the work was done it was stored the entire time. How do I go about warranty requests? Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 19, 2020 Report Share Posted August 19, 2020 46 is sensor ground. Please check with voltmeter connected between pin 1 and 71 or 72. Check with ECU plugged in and ignition switch on. Quote Link to comment Share on other sites More sharing options...
Dualxeon64 Posted August 19, 2020 Author Report Share Posted August 19, 2020 Ok I went negative to pin one and power to 72 and I have power but at 71 no power Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 19, 2020 Report Share Posted August 19, 2020 13 minutes ago, Dualxeon64 said: but at 71 no power Are you checking this with the ecu plugged in like I said? Because 71 & 72 are linked together internally, you should get exactly the same voltage on both if the ecu is plugged in - even if there was no wire connected to 71. Quote Link to comment Share on other sites More sharing options...
Dualxeon64 Posted August 19, 2020 Author Report Share Posted August 19, 2020 Yes ecu is plugged in and the key is on. I get power at 72 but not at 71. Sorry I did the wrong 2. Double checked the image you sent. This time I had power at both doing the correct pins. Forgot that the image has the tab so you know which side of the plug is which. Quote Link to comment Share on other sites More sharing options...
Vaughan Posted August 19, 2020 Report Share Posted August 19, 2020 The pins by the red arrow are ign switched 12V and the pins by the black arrow are grounds connected to the bottom of the intake manifold (On an early 90s mr2) Quote Link to comment Share on other sites More sharing options...
Dualxeon64 Posted August 19, 2020 Author Report Share Posted August 19, 2020 9 minutes ago, Vaughan said: The pins by the red arrow are ign switched 12V and the pins by the black arrow are grounds connected to the bottom of the intake manifold (On an early 90s mr2) Not sure where you are going with this. I do know I have those grounds connected. Quote Link to comment Share on other sites More sharing options...
Vaughan Posted August 19, 2020 Report Share Posted August 19, 2020 2 minutes ago, Dualxeon64 said: Not sure where you are going with this. I do know I have those grounds connected. if you don't have 11V at both of those pins by the red arrow when the key is on and the engine is not running you have wiring issues. Also if you don't have 11V between the pins by the black arrows and the pins by the red arrow while the key is on and the engine is not running you quite possibly have ground issues Quote Link to comment Share on other sites More sharing options...
Dualxeon64 Posted August 19, 2020 Author Report Share Posted August 19, 2020 8 minutes ago, Vaughan said: if you don't have 11V at both of those pins by the red arrow when the key is on and the engine is not running you have wiring issues. Also if you don't have 11V between the pins by the black arrows and the pins by the red arrow while the key is on and the engine is not running you quite possibly have ground issues Got it and I am only getting 5.56 volts at both. So maybe a short in the wires somewhere? Not even sure where to start looking the harness was not messed with other than inspection for broken wiring which I had not found any. Quote Link to comment Share on other sites More sharing options...
Vaughan Posted August 19, 2020 Report Share Posted August 19, 2020 that sounds like a bad ground, bad relay or blown fuse, I would start with the EFI Main Relay ECU power goes through the EFI Fuse then through the EFI Main relay then straight to the ECU Quote Link to comment Share on other sites More sharing options...
Dualxeon64 Posted August 19, 2020 Author Report Share Posted August 19, 2020 Just now, Vaughan said: that sounds like a abd ground, bad relay or blown fuse, I would start with the EFI Main Relay So the 15amp fuse is good. I did note that the efi fuse was super hot to the touch. When i removed it to stop power to the ecu. Quote Link to comment Share on other sites More sharing options...
Vaughan Posted August 19, 2020 Report Share Posted August 19, 2020 if it 5.56 between the ECU pins but 11V from chassis to ECU Pins then bad ground, if 5.56 from chassis to ECU pins as well as between then the fuse, relay or power wiring. The main ground for the engine goes from the gearbox to the chassis beside the side gearbox mount 2 minutes ago, Dualxeon64 said: So the 15amp fuse is good. I did note that the efi fuse was super hot to the touch. That shouldn't be getting hot, a short in the engine loom could cause that though. I have had an mr2 loom fray, break and short out in the past. The ECU power is also used to power the fuel pump, Boost VSV, TVIS VSV, ISC Valve, EGR VSV (if present) and O2 sensor (if it is a 4 wire one). The Check connector +B pin is also supplied by the EFI Main relay. Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 19, 2020 Report Share Posted August 19, 2020 The most common problem I see after engine swaps is a wire caught/clamped somewhere it is not meant to be - like between the block and bellhousing or starter motor etc. I dont know MR2's well but since it was ok before the swap and not ok afterwards, that would be the first thing I would look around for. Quote Link to comment Share on other sites More sharing options...
Dualxeon64 Posted August 20, 2020 Author Report Share Posted August 20, 2020 23 hours ago, Vaughan said: if it 5.56 between the ECU pins but 11V from chassis to ECU Pins then bad ground, if 5.56 from chassis to ECU pins as well as between then the fuse, relay or power wiring. The main ground for the engine goes from the gearbox to the chassis beside the side gearbox mount That shouldn't be getting hot, a short in the engine loom could cause that though. I have had an mr2 loom fray, break and short out in the past. The ECU power is also used to power the fuel pump, Boost VSV, TVIS VSV, ISC Valve, EGR VSV (if present) and O2 sensor (if it is a 4 wire one). The Check connector +B pin is also supplied by the EFI Main relay. Alright I found the broken wiring. The 2 power wires go into one just under the fuse box in the bay. They where corroded and when I split the harness they separated. Got that fixed and yay my car starts right up.. Thank you guys for all your help on this. Vaughan 1 Quote Link to comment Share on other sites More sharing options...
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