Update Custom Module Record

Update Custom Module Record

I am trying to update an existing record in a custom module.

When I try to get my modules, I see:

{
          "content": "CustomModule1",
          "gt": "4",
          "id": ...,
          "no": "6",
          "pl": "Cohorts",
          "sl": "Cohort"
        }

So I know that the module is called "CustomModule1". I want to update a custom field on this custom module, so I pulled the fields:

{
          "customfield": "true",
          "dv": "Cohort Status",
          "isreadonly": "false",
          "label": "Cohort Status",
          "maxlength": "120",
          "req": "false",
          "type": "Pick List",
          "val": [
            ...
          ]
        },

When I try to update, the XML I pass is:

<CustomModule1>
      <row no="1">
            <FL val="Cohort Status">${this.status}</FL>
      </row>
</CustomModule1>

I receive this error:

<?xml version="1.0" encoding="UTF-8" ?>
<response uri="/crm/private/xml/CustomModule1/updateRecords"><error><code>4835</code><message>Unable to parse XML data</message></error></response>

What is missing in my XML? I am using node to POST to the API, and I URI encode my XML. This works with inserting leads, so I am not sure what would be different about updating a record?