I have a 97 ford expedition with 206329 miles on it and I am getting codes B1867 which I looked up and it says BATTERY POWER SUPPLY ECU CIRCUIT SHORT TO GROUND. B1913 which says AIR BAG DRIVER/PASSENGER CIRCUIT SHORT TO GROUND. P0133 02 SENSOR SLOW RESPONSE BANK SENSOR 1. But I can't find anything online that could tell me how to fix these problems could any one help me out with these codes thanks.

Disconnect the negative battery cable and try cleaning the main PCM ground.

Disconnect the negative battery cable and try cleaning the main PCM ground.

Where is the main pcm ground located I try to find it on the internet but I can't find a picture of the actual ground wire.