ECU Grounds... Where are they?

btwilson86 · 05-28-2007, 04:42 AM

So... I have a code 11 when I run diagnostics (disrupted power to ECU). I'm told that it's most likely a bad ground or short somewhere, as the car still runs fine. I found somewhere on this forum the pin out diagram for the ECU on a 1990 N/A Auto tranny. I have a 87 N/A Auto, so I'm wondering if the grounds between the two ECU's are the same. Anyone know? Cuz I heard that in 89 or something they added a sensor that detects a high altitude to adjust the air/fuel mixture, and I'm hoping that Toyota just utilized an unused pin on the ECU.

I've also been told that the housing on ECU's in some later model Toyotas are the computer ground, and that just bolts to the frame to get grounded....

It's all kind of giving me a headache, and I don't particularly want to ruin my ECU by grounding a wire that shouldn't be grounded, so if anyone has any ideas, it'd be very much appreciated.

05-28-2007, 04:42 AM	#1
btwilson86 Super Moderator Join Date: May 2007 Location: Billings, Montana Posts: 1,034	ECU Grounds... Where are they? So... I have a code 11 when I run diagnostics (disrupted power to ECU). I'm told that it's most likely a bad ground or short somewhere, as the car still runs fine. I found somewhere on this forum the pin out diagram for the ECU on a 1990 N/A Auto tranny. I have a 87 N/A Auto, so I'm wondering if the grounds between the two ECU's are the same. Anyone know? Cuz I heard that in 89 or something they added a sensor that detects a high altitude to adjust the air/fuel mixture, and I'm hoping that Toyota just utilized an unused pin on the ECU. I've also been told that the housing on ECU's in some later model Toyotas are the computer ground, and that just bolts to the frame to get grounded.... It's all kind of giving me a headache, and I don't particularly want to ruin my ECU by grounding a wire that shouldn't be grounded, so if anyone has any ideas, it'd be very much appreciated. __________________ 1989 7MGTE R154 Targa Top White Package w/Blue Interior Driftmotion 57trim CT26, Upgraded Intercooler, 2.25" Hard Pipes, 3" Turbo Back Exhaust with Test Pipe, HKS VPC w/GM 3 bar MAP sensor, APEXi S-AFC, Walbro 255lph fuel pump, ProSport EVO Series Boost / Fuel Pressure / AFR gauges, Lotek a Pillar Gauge Pod, HKS Type 0 Turbo Timer, Eibach Lowering Springs, Tokico Illumina II TEMS struts, custom powder coated Motegi Racing TrakLite wheels