1g ECU and harness in a 94 Galant

[eclipsh]

Hey all,

I have an interesting challenge ahead of me. I am building a mid 90's Galant VR-4 using my recently acquired 95 Talon AWD as a donor. However I hung onto all my nifty DS-MAP (aka Jackal) speed density goodies from my old 1g and want to run them in my new build. Problem is they only work with a 1g ECU. So I'm looking at putting a 1g ecu, and if necessary a 1g harness, into the Galant which will by necessity be running a 2g motor.

Soooo... I'm trying to figure out how to make this work. I know the 1g harness fairly well but I am not familiar with the 2g wiring harness. I do know that the turbo motor swap into the Galant has been done by members on this site so the wiring for that leap has been covered (likely very little as they share so much else).

What I don't know is if with some creative rewiring it becomes possible to run a 1g ECU on the 2g (or Galant) wiring harness without major errors. If not, I'll need to track down any wiring issues with running the 1g harness in the 2g such that all the gauges work properly. A lot of this may just come down to hours of tracing wiring diagrams but if anyone has input I'd really appreciate it.

 

[amg_dragon]

I'm not familiar with your speed density 'goodies' but I personally think you're asking more more headaches than anything trying to integrate 2 different systems into a third. I guess for some reason you're opposed to dsmlink? I'd say sell off your goodies and purchase a link if possible. First, you won't have half the hassles and second you won't take an already difficult platform to obtain parts for and make it that much more difficult to obtain parts and service for. On a personal note I feel you would trash the value of the car by hacking it apart making it next to impossible to sell if it turns out to be too much effort to make work. If you reaaaaly have your heart set on speed density, check out a full standalone system.

Or, is it truly too hard to trace out the 1g SD to integrate into your 2g system? I think it would be easier than tracing out every wire and re-pinning them. Not to mention the extra 14 pins a 1g ecu has.

 

[eclipsh]

DS-MAP.NET • Index page for the speed density stuff. It uses an Ostrich 2.0 EPROM emulator, native WBO2, 3 BAR MAP, & IAT along with some free software to run native speed density with full control over VE, timing, fuel maps, injector size & pulse width and a few other bells and whistles. I have no interest in going with DSM-Link when I have this to use. Unfortunately no one is willing to share the 2g ECU data needed to run DS-MAP on that ECU so I will have to run a 1g unit.

I suppose I also explained the conversion in a bit of a strange way. I'll be running a 1g ECU with a 2g long block in a 7g Galant which closely resembles a 2g. In the end I'll probably just run the 1g engine harness as well and splice whatever wires I need to to make the gauges work from there. I know I'll be needing the 1g CAS but I don't know what else I'll need to switch as far as sensors/ignition components. I just want to see if anyone else has some knowledge from doing something similar.

 

[twdorris]

What I don't know is if with some creative rewiring it becomes possible to run a 1g ECU on the 2g (or Galant) wiring harness without major errors.

Certainly. I run a 1G ECU in my 2G DSM (and my EVO8) fairly often for testing purposes. You'll need to pay attention to the knock sensor (needs to be a 1G knock sensor to work properly with a 1G ECU) and you'll need to run the fans manually. Other than that and the obvious rewiring of the ECU harness, there's not much else to it.

Pinouts for a 1G and 2G ECU can be found here.

ecuwiringinformation [ECMTuning - wiki]

You'll need to sit down and scribble out the mapping between the two and then either build an adapter harness or manually wire in the 1G connectors.

Thomas Dorris
ECMTuning, Inc.

 

[eclipsh]

Thanks Thomas, that helps. I'll need to find the pin-outs and good wiring diagrams for the Galant then I think I will run the 1g harness/ecu and will know which wires to run for gauges. I'll also look into using an automatic temperature switch for the radiator fan.

 

[eclipsh]

So I went and got my 94 Galant ES and a 1G ECU today. After getting some advice of the Galant Center boards I have found that I will be able to swap in the 1g ECU connectors, run a few extra wires for the coil pack, knock sensor and some other bits and I should be good to go.

 

[tom04841]

Your galant has 3 ecu plugs which are identicle to the 1g ecu. PM DOHCstunr on thegalantcenter.net. He has done the swap and runs the same setup you are attempting.

 

[eclipsh]

Your galant has 3 ecu plugs which are identicle to the 1g ecu. PM DOHCstunr on thegalantcenter.net. He has done the swap and runs the same setup you are attempting.

Actually that was exactly who I talked to

Thankfully I have a 91 power transistor lying around and a 91 JDM A/T VR-4 wiring harness hanging in the garage so I can use that transistor and harness to get the parts I need. I'll just pull the clips right out of the ECU plug and pull the complete wires from the harness.

Unfortunately the extra coil pack I have lying around is from a 90. I'll look into seeing if it will work. I was going to pull one at the yard but spaced it. I forgot to pull the knock sensor I need too The CAS I have is also from a 90 so I'll need to see if that will be ok. If not I'll go hit a yard closer to home and get the extra parts I need.

 

[eclipsh]

So now I'm playing with wiring diagrams trying to properly connect whatever I can from the 7g harness and adding what I need to from the 1g harness to make a complete unit. Here's what I've got so far... (this is also up on the galant center). The bold areas are what I still need to work on.

7g PIN Function 1g PIN
1 #1 INJECTOR 51
2 #3 INJECTOR 60
3 FAN MOTOR RELAY N/A
4 IAC (CLOSED) 0-1V KOEO
5 IAC (VALVE #1) 0-1V or 4.5-5.5v load controlled
6 EGR SLND 53
7 TCU N/A
8 FUEL PUMP RELAY
9 PURGE CONTROL SLND 62
10 IGNITION POWER TRANSISTOR, 0.3-3.0v with engine at 3k RPMS
11 A/C INTERMEDIATE SWITCH OR A/C PRESSURE SWITCH
12 POWER – KOEO (key on engine on)
13 GROUND
14 #2 INJECTOR 52
15 #4 INJECTOR 61
16 FAN LOW
17 IAC (OPEN) 0-1V KOEO
18 IAC (VALVE #2) 01 OR 4.5-5.5V LOAD CONTROLLED
19 MAS RESET (91+) 6
22 A/C CLUTCH 65
23 IGNITION POWER TRANSISTOR, 0.3-3.0v at 3k rpms
24 ELECTRIC LOAD SWITCH (LIGHTING ON/OFF) ignore?
25 POWER – KOEO
26 GROUND
34 IGNITION TIMING ADJ. 12
35 HEATED O2 FRONT, 0-3v KOER
36 CEL WARNING LAMP 64
37 POWER STEERING SWITCH 5
45 A/C SWITCH 0-3V KOER
51 IGNITION SWITCH START 108
52 INTAKE AIR TEMP 8
53 EGR TEMP SENSOR 15
55 HEATED O2 REAR
56 HEATED O2 FRONT, 0-0.8V KOER 2K RPMS
60 BATTERY BACKUP 103
61 ? SENSOR +5V or TPS? 23 = 5V POWER FOR BARO SENSOR AND TPS, 4.5-5.5V KOEO
63 ENGINE COOLANT TEMP 20
64 TPS 19
65 BAROMETER 16
66 VEHICLE SPEED 18
67 CLOSED THROTTLE/IDLE) 14
68 CAMSHAFT POSITION, 0.5-2V KOER
69 CRANKSHAFT POSITION or COOLANT TEMP SENSOR 1.5-2.5V KOER
70 VOLUME AIRFLOW 10
71 PARK/NEUTRAL (A/T)
72 COOLANT TEMP SWITCH (KOEOff)

The 1G pins I don't have connections to yet are:

102 12V from MPI relay pins 4&5
105 wastegate solenoid output
107 12v from MPI pins 4&5
109 Tach input
110 Ignition switch (IG1) input
54 ignition trigger 1&4
55 ignition trigger 2&3
56 MPI relay pin 7
57 fuel pressure solenoid
58 ISC coil A1
59 ISC coil A2
63 MPI relay pin 8
66 MPI relay pin 8
67 ISC coil B1
68 ISC coil B2
3 boost gauge
4 Oxygen sensor input (will wire in my WBO2 so no worries there)
7 A/C coolant temp switch
9 knock sensor (will have to run wires)
11 ABS control unit output
13 fuel pump voltage monitor input
17 sensors ground
21 crank angle sensor
22 TDC sensor
24 sensors ground

 

[eclipsh]

If anyone is interested in following my AWD conversion thread it is over here:

1g DSM ECU/Harness in my AWD Galant? - The Galant Center

 

[eclipsh]

I need some help on this last bit of wiring for the MPI/MFI relay and could use some input on making sure everything else is wired up right if anyone feels like going over it.

Looking at the diagram below, it looks like the Galant takes pin 6 of the MPI relay straight to ground along with pins 13 and 26 of the ECU.

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In the 1g ECU pin 8 of the MPI relay looks like it carries out the same function but goes to pins 63 and 66 of the 1g ECU rather than to ground.

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What I'm wondering is if I should cut the wire from pin 6 of the Galant relay to route it to pins 63 and 66 of the 1g ECU or if I should just continue to let it run to ground and skip wiring up the two 1g ECU pins.

If anyone wants to look into how I did the rest of the wiring please check out the thread linked above. I'd love to have anyone I can get looking over my shoulder to make sure this is done right the first time.

 

[eclipsh]

The car isn't running yet Hak. I had to go and get a job which severely cut back on my garage time. On the plus side it gave me some income so I could eat and buy a nice FMIC kit. My dad and I did end up with a nice carrier bearing bracket for the drive shaft so that much is done.

I ended up just cutting the wire I'm talking about above and running it into the 1g ecu. I still need to find out where the tach signal is going to go in the Galant harness, finish wiring my wideband and one or two other little wiring issues but otherwise the wiring looks like it is done. Now I just have to cross my fingers and hope it all works. I've got the full list of my ECU wiring up on my TGC thread.

 

[eclipsh]

Well the wiring didn't work out quite right and I am in the process of tracking it down. The fuel pump is not getting tripped on when I crank the engine over. Looking at my wiring, I don't have anything running to the 1g ECU Pin 13 and can't find anything in the factory manual on it. One diagram I found online says it is the control relay for the fuel pump drive signal. My wiring diagrams for the fuel pump don't show anything that could resemble this.

I am getting signals from all my sensors, though the TPS is giving odd readings and capping out at about 47%, starting at 7%.

When I jump the fuel pump to get pressure it still doesn't want to fire up. I'm getting spark so it should just be a question of fuel. I don't know if the injectors are being tripped or not at this point, though my logger is giving me readings for what the ECU is sending out to them.

The last little challenge is that I am using an ECU which is untested. I pulled it from a salvage yard, replaced the capacitors and socketed it. Unfortunately I don't have a good way to test it either.

So for now the car is sitting in my driveway just waiting to run and get the interior cleaned up and reinstalled.

EDIT: Looks like the starting issue is mostly resolved. The car fires up but won't stay running. The fuel pump is triggering though. I think I'm losing power to the ECU as my logger is also losing the signal when the car stops running. I'm going to go through all my power wires and see what I can figure out.

 

[eclipsh]

Update:

I went over and tested all the wires, moved the power supply for Pin 110 to IGN1 instead of Start and wired Pin 13 to the MPI fuel pump wire, then reinstalled the harness. Now the ECU is getting power consistently and will communicate with the logger with the ignition in the "on" position but I'm still only getting 2.8v to the TPS and the MAP sensor. Both of these are powered by Pin 23 of the ECU which should be sending 5v. I checked at the ECU and of course I get the same 2.8v. To me that says I probably have a problem within my ECU, possibly my capacitor replacement gone wrong. I'll be sending the ECU out to Steve for diagnostics and possible repair tomorrow.

I've got lots more info and pictures up in my thread at The Galant Center for those interested in how the project has gone. All the mechanical work is done. Now it is just fixing the wiring.

 

[steve]

Well the wiring didn't work out quite right and I am in the process of tracking it down. The fuel pump is not getting tripped on when I crank the engine over. Looking at my wiring, I don't have anything running to the 1g ECU Pin 13 and can't find anything in the factory manual on it. One diagram I found online says it is the control relay for the fuel pump drive signal. My wiring diagrams for the fuel pump don't show anything that could resemble this.

Pin 13 is the sense line for the fuel pump. You'll find it listed in the 1G Tech manual and the actual 1990 FSM but it's missing from the later manuals. Without it the ECU will throw the fuel pump CEL as soon as the ECU turns on it's output on pin 56. Pin 13 connects to pin 2 on the MPI relay (or wherever your power for the fuel pump is being sourced from.

I'll look at the rest of your questions later.

 

[eclipsh]

Thanks for looking into my thread Steve. I did run Pin 13 to Pin 1 of the Galant MPI relay which looks to perform the same function as pin 2 of the DSM relay, ie power to the fuel pump. You can see both in the diagrams I posted above. I ran through my harness and double checked all the sensor wires and they are routed to the correct locations. All the other sensors are also sending back believable numbers to the ECU, just not the TPS. Oh and it was the positive lead of the large solo capacitor that I burned the board at.

 

[eclipsh]

Oh, one thing I failed to mention earlier is that I'm seeing 12v at pin 3 of the TPS. The factory seems to think I should be seeing 0-1v.

 

[steve]

Pin 3 as in the Idle Position Switch pin in the TPS?

 

[eclipsh]

Yup, the idle position switch.

 

[steve]

With the throttle closed you should see close to 0v there and 5v or more with the throttle slightly opened.
The IPS just switches the wire to the ground when the throttle is closed. The ECU pulls it up. IIRC, the pull up voltage differs between 5v and battery depending on the ECU year but the memory is foggy as to which is what.

 

[eclipsh]

Thanks Steve. I was testing voltages by pulling the plug off so of course I was seeing maximum voltage based on what you're saying. I shipped the ECU off to you this afternoon priority mail. At this point I'm not sure if I should hope something is wrong and you can fix it or that it is fine

 

[eclipsh]

Well I dug through the harness again after confirming that I was getting 12v to the ECU and had good grounds. Turns out that thanks to my reusing parts of the Galant harness I managed to leave the power for the ISC hooked to pin 23. The ISC should get 12v from the MPI relays. I think this was trying to draw so much power from pin 23 that it dropped the voltage to the other sensors and gave me my problem. So that is fixed and I'm going to go get my repaired ECU (thanks Steve) from the post office this morning.

 

[steve]

Hopefully that's it. The ISC shouldn't be connected to sensor power and isn't on the Galant either.

 

[eclipsh]

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That did it. Now on to other parts of the project.

 

[steve]

Cool. Have fun.