There are so many threads here about the bigger ground straps between the body and the drivetrain, but not much mention of the ground for the ECM/MCM/BCM. It's on the cylinder head, between the valve cover and the MAP sensor. Mine left me stranded. Check yours now!
I was getting a flickering check engine light all day. Not flashing, just random flickering. Then it was mostly on. Still running normal. I shut the engine off at a light (no IMA or autostop). When I tried to restart the engine, it just cranked without firing. Luckily I was able to push the car into a well-lit parking lot. Fuel pump was not coming on. I checked fuses, relays, fuel pump wires, etc. Nothing seemed wrong. The big grounds were OK and everything else on the car was working. I even had someone bring me my spare ECMs to try. I gave up and towed it home.
I eventually got it to start in my driveway. I was getting all kinds of random trouble codes that didn't make sense. Something led me to the G101 terminal on the cylinder head. It has three wires on it. One wire broke off when my finger touched it, and another wasn't much better. The third wire took some effort to break.
Of course the copper wires were corroded when I stripped the insulation off. They needed to be cleaned before replacing the terminal. I read that vinegar and salt will clean the copper, and rinsing with baking soda dissolved in water will neutralize the acid. I also sprayed the wires with WD40 before putting the new terminal on. I used a waterproof heat shrink crimp terminal.
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I was getting a flickering check engine light all day. Not flashing, just random flickering. Then it was mostly on. Still running normal. I shut the engine off at a light (no IMA or autostop). When I tried to restart the engine, it just cranked without firing. Luckily I was able to push the car into a well-lit parking lot. Fuel pump was not coming on. I checked fuses, relays, fuel pump wires, etc. Nothing seemed wrong. The big grounds were OK and everything else on the car was working. I even had someone bring me my spare ECMs to try. I gave up and towed it home.
I eventually got it to start in my driveway. I was getting all kinds of random trouble codes that didn't make sense. Something led me to the G101 terminal on the cylinder head. It has three wires on it. One wire broke off when my finger touched it, and another wasn't much better. The third wire took some effort to break.
Of course the copper wires were corroded when I stripped the insulation off. They needed to be cleaned before replacing the terminal. I read that vinegar and salt will clean the copper, and rinsing with baking soda dissolved in water will neutralize the acid. I also sprayed the wires with WD40 before putting the new terminal on. I used a waterproof heat shrink crimp terminal.
