I am trying to prepopulate a text array using the start URL.
https://localhost/index.php?r=survey/index/sid/588745&lang=en&newtest=Y&PersonalDetails_Personal_Title=Mr
Where PersonalDetails is the question code, Personal is the Y axis code and Title is the X axis code.
Nothing gets displayed in the array.
When I try this with a simple short text answer it does work.
https://localhost/index.php?r=survey/index/sid/588745&lang=en&newtest=Y&Phone=1234567890
Where the question code is Phone and the answer is populated with the right number.
What am I doing wrong?

www.limesurvey.org/manual/SGQA_identifie...8Number.29_Questions

Yes, as jelo suggests, you can use the full SGQA in the URL.

So, for example, given:

• Survey ID - 111111
• Group ID - 22
• Question ID - 33
• Sub-question ID - SQ001
• Answer ID - A1

Something like this will work:

Or: www.limesurvey.org/manual/URL_fields#Start_URL