This is a 96 with a 4.9 and 4 wheel ABS. Checked relay, fuse, power and grounds at the module, put on a new module for the ABS, and still getting these codes with the KOEO test. Light is off until you drive a short distance. Any help or suggestions on this one?

 

Can we ask how did you check the relay ?
It is in the power dist panel in engine compartment.

 

Yes this relay is in the engine compartment near the battery. I have switched the relays around all three of them. Then I did resistance tests on them, grounded the wire on circuit #599 at the module to cause the relay to close and then had power at circuit 532 at the module and HCU. Checked power and grounds again at the ECU brake module Checked brake on off switch at the module. Made sure the battery is fully charged. Checked brake fluid level switch. Followed the pin point test for these codes. But doing KOEO test, I always get these 2 codes, which say “Fix First”

 

Some systems run a diagnostic check of the integrity of the connections when you first turn the key on. If there is any kind of problem it will notify the operator .The vehicle may not even have to be moved to conduct this test, some will produce the notice right after it starts moving. In any case a thorough check needs to be done from the beginning to the module .The majority of the time it involves poor connections.