Code 11

[Mike Morris]

My check engine light comes on after about 7 miles of driving even after clearing codes per Super Monitor.
The code means at the some point the ecm is losing signal/power.
All connectors are tight on the ecm. HKS ad ons(fcon,vps,gcc) the same. Ignition is stock. Car has brand new Toyota plug wires. Harness for HKS addons is good as well. I replaced the wiring harness in engine bay with a new one about 5 years ago and the car maybe has 5K since then. Coilpacks were replaced at the same time with new Toyota units. Alternator is a new Toyota unit from 2003. New battey 2 years ago-connectors are tight and clean.
I did notice the coil pack tray ground wire looks a little rough-will replace it.
I did notice the clear cap on the 30amp fuse under the engine fuse box was missing(labeled "cds" on the lid). I will replace that.
Any other things to check and locations? I can't find my service manual

 

[GrimJack]

ECU ground location is at the back bottom end of the intake manifold, check those. Also check the other ground locations - block to chassis, etc.

 

[Mike Morris]

Thank you!

 

[92TealSupra]

next tot he inetrcooler piping on the passenger side where it comes up through the chassis there is also another ground there, and another one right next tot he fuse box, just make sure they're all good, and if I were you check check over the engine bay to make sure everything is tight and sound.

 

[Mike Morris]

Where exactly is that ground by the intercooling pipes?
Thanks.

 

[jetjock]

^ Doesn't matter as it can't possibly contribute. The left fender one (GP C) should be checked though because it supplies ground for the main relay.

That said even though it's unlikely grounding is involved the possibility can be checked using several methods. For the electrically challenged the easiest (but least accurate) is to temporarily connect a jumper from battery negative to E1 in the diag block.

 

[Mike Morris]

Thanks