hl6528RD - Error GPS Commands

Hello,

I’m having problems to get the GPS working in my HL6528RD module. It gives me back an error every time I try to send any gps related commands.

I can read these commands:
AT+CGMI
Sierra Wireless

AT+CGMM
HL6528RD-2.8V

AT+CGMR
RHL6528RD.2.4.3.11CV10F49.201709160006.m6261a_1

AT+WMGNSSTEST=?
+CME ERROR: 3

I’ve tried in 3 different modules and it’s always the same response. Driving the module through UART, the GPRS works fine.

I can’t find any other commands than: “AirPrime HL6528RDx - AT Commands Interface Guide” but none of these AT commands seem to work for the GPS.

Any idea?

Thanks