@Ecg,
CPEs are designed for directional links over very long ranges. They are not suitable for spreading a WiFi signal around as omnidirectional APs do. Reason for this is that CPEs have an antenna beam width of only 65º in one direction to concentrate RF energy, while omni antennas have a beam width of 360º, but much lower coverage.
Depending on your mounting location, you probably can use Repeater or Bridge modes of a CPE to supply standard WiFi devices (e.g. see this thread where someone claims that a CPE indeed does supply the WiFi signal to the building the CPE is mounted on, but I can not second this without exact knowledge on how the CPE is mounted and my experience in feeding standard WiFi clients using a CPE is much like yours – it's just not reliable b/c CPEs are not designed for this use case).
If you could mount the CPE so that your garage is inside its 65º angle, repeating the WiFi signal could work.
Another, much more reliable solution is to add an omnidirectional AP such as EAP225-Outdoor connected by cable to the 2nd CPE running in Client mode.
But then question is whether it would be sufficient to use only one EAP225-Outdoor mounted at the home building and avoid CPEs at all since EAP225-Outdoor can cover up to 100m and standard clients should be able to send something back over this distance, too (at least if there is a free line of sight between them). I can only guess: if your garage is a metal box, it won't work with one EAP225-Outdoor alone; if it is a wooden car port, it almost certainly will work fine if your WiFi clients have good antennas, too.
An alternative solution would be to have the 1st CPE at the home connect to an EAP225-Outdoor which then serves as a relay to other WiFi clients connected to the EAP. Since the EAP only supports AP mode, your 1st CPE needs to run in Client mode: