Where is engine ground on 89?
08-12-2004, 06:44 PM
#2
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Originally Posted by evitagenone
I need to find the engine ground for the ECM? Anybody know where to find it?
I believe and I could be wrong, that all the grounds from ECM and in the cockpit are at the upper tranny case bolt on the passenger side. You should (emphasis on should) be able to see them from underneath the car, However as with many things on these cars, seeing isn't reaching 
08-12-2004, 06:57 PM
#3
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I had checked my service manual wiring schematic, for him, and found no grounds in the pinouts for an '84. It doesn't ground through the ECM case mount, because mine runs just fine with the ECM sitting on the floor on the carpet.
I don't believe the ECM has to be grounded. It receives 12 volts from the battery, and sends signals to the affected device, which grounds by being activated and completes the circuit.
RACE ON!!!
I don't believe the ECM has to be grounded. It receives 12 volts from the battery, and sends signals to the affected device, which grounds by being activated and completes the circuit.
RACE ON!!!
Last edited by CFI-EFI; 08-12-2004 at 07:00 PM.
08-12-2004, 07:07 PM
#4
Look under the drivers side under the dash near the door jamb. That is the grounding point for the dash harness which on an 84-85 is where the ECM would ground through. On and 86-89 though it is throuh a VATS module. This is how the VATS system disables, it will not allow a ground signal to the ECM and it interupts the starter.
08-12-2004, 07:21 PM
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snaketr,
Can you please elaborate? I am interested in the '84. The poster is interested in the '89. I don't mean to high-jack his thread. It makes sense to me that the ECM would have a ground, but as I stated, there is no pinout, so identified on my schematic. Do you have any idea where the connection is on the ECM, or what pin it is related to? Thanks,
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Can you please elaborate? I am interested in the '84. The poster is interested in the '89. I don't mean to high-jack his thread. It makes sense to me that the ECM would have a ground, but as I stated, there is no pinout, so identified on my schematic. Do you have any idea where the connection is on the ECM, or what pin it is related to? Thanks,
RACE ON!!!
08-12-2004, 08:15 PM
#6
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The ECM grounds (There are 4 of them) all end up going to a stud/bolt (bellhousing to engine) on the driver side.
You'll also see a braided wire from there to the chassis/ frame.
You'll also see a braided wire from there to the chassis/ frame.
08-12-2004, 08:48 PM
#8
Le Mans Master
Which one are you looking for? There are two ECM grounds on the transmission stud with the braided cable from the frame. I know the third ground at this location is from the cluster. I'm pretty sure the other grounds, brown and tan are with the negative battery cable just above the oil filter. The Service Manual isn't a big help here, because it identifies both locations as G104, except in the illustrations, where it identifies the negative cable site as G101. If you post which one you want, I sure I can find the specific circuit.
08-12-2004, 09:00 PM
#9
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Originally Posted by CFI-EFI
I have failed to make my question clear. Where in or on the ECM is the ground picked up or connected?
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08-12-2004, 09:47 PM
#10
Le Mans Master
So you want the Pinouts for a X-Fire? I don't have a schematic, but my resource says White 12 & 13 are the main grounds. The other White Pin grounds are 14, MAP; and 21, a/c clutch (also for the fan if the a/c is on). Black Pin 3 is the ignition module ground; Black 11, Coolant & TPS grounds; and Black 15 is the O2 ground.
08-12-2004, 10:20 PM
#11
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Thanks for the info. I found the ground on the bellhousing and reconnected them. I still have yet to find out why my injectors keep going out. For some reason the computer keeps getting burnt by the injectors.
08-12-2004, 11:33 PM
#14
Le Mans Master
Just read you're burning up the ECM - weird - try to get a hold of JFB - he's the electrical engineer. I would think that the injector fuses would blow and save the ECM. Make sure you've got the right amperage - the '89 was upgraded to 20 amps for the Injector 1 fuse; the Injector 2 to 10 amps. Offhand, are the fuses switched?
Injector 1 fuse also powers up all the telltales - door ajar; service engine soon; select ride; anti-lock and the brake warning.
Injector 1 fuse also powers up all the telltales - door ajar; service engine soon; select ride; anti-lock and the brake warning.
08-13-2004, 11:46 AM
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Originally Posted by SunCr
So you want the Pinouts for a X-Fire?
Your sources are largely correct. *I* have the factory service manual, and I spent considerable time with the wiring diagram in order to aid evitagenone with his problem. I didn't see any of the pins labeled as "grounds". Most of your cited examples are called "returns" of one sort or another. It makes sense to me, now, that a return, is what *I* would think of as a ground. You have been very helpful. Thank you, and...
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