diff --git a/packages/core/src/awsService/ec2/model.ts b/packages/core/src/awsService/ec2/model.ts
index 9a5e13feaef..42d69828aa7 100644
--- a/packages/core/src/awsService/ec2/model.ts
+++ b/packages/core/src/awsService/ec2/model.ts
@@ -36,7 +36,7 @@ import { SshKeyPair } from './sshKeyPair'
 import { Ec2SessionTracker } from './remoteSessionManager'
 import { getEc2SsmEnv } from './utils'
 
-export type Ec2ConnectErrorCode = 'EC2SSMStatus' | 'EC2SSMPermission' | 'EC2SSMConnect' | 'EC2SSMAgentStatus'
+export type Ec2ConnectErrorCode = 'EC2SSMStatus' | 'EC2SSMPermission' | 'EC2SSMTestConnect' | 'EC2SSMAgentStatus'
 
 export interface Ec2RemoteEnv extends VscodeRemoteConnection {
     selection: Ec2Selection
@@ -215,8 +215,8 @@ export class Ec2Connecter implements vscode.Disposable {
                 remoteUser.name
             )
         } catch (err) {
-            const message = err instanceof SshError ? 'Testing SSH connection to instance failed' : ''
-            this.throwConnectionError(message, selection, err as Error)
+            const message = err instanceof SshError ? `Testing SSM connection to instance failed: ${err.message}` : ''
+            this.throwConnectionError(message, selection, { ...(err as Error), code: 'EC2SSMTestConnect' })
         } finally {
             await this.ssmClient.terminateSession(testSession)
         }
diff --git a/packages/core/src/shared/extensions/ssh.ts b/packages/core/src/shared/extensions/ssh.ts
index ba349a902c2..44af313d108 100644
--- a/packages/core/src/shared/extensions/ssh.ts
+++ b/packages/core/src/shared/extensions/ssh.ts
@@ -130,6 +130,15 @@ export class RemoteSshSettings extends Settings.define('remote.SSH', remoteSshTy
     }
 }
 
+/**
+ * Test a SSH connection over SSM.
+ * @param ProcessClass given process to test the connection within.
+ * @param hostname
+ * @param sshPath
+ * @param user
+ * @param session SSM session credentials. These cannot be reused, so it may be required to create a seperate session for the test connection.
+ * @returns
+ */
 export async function testSshConnection(
     ProcessClass: typeof ChildProcess,
     hostname: string,
@@ -137,20 +146,18 @@ export async function testSshConnection(
     user: string,
     session: SSM.StartSessionResponse
 ): Promise<ChildProcessResult | never> {
+    const env = { SESSION_ID: session.SessionId, STREAM_URL: session.StreamUrl, TOKEN: session.TokenValue }
+    const process = new ProcessClass(sshPath, ['-T', `${user}@${hostname}`, 'echo "test connection succeeded" && exit'])
     try {
-        const env = { SESSION_ID: session.SessionId, STREAM_URL: session.StreamUrl, TOKEN: session.TokenValue }
-        const result = await new ProcessClass(sshPath, [
-            '-T',
-            `${user}@${hostname}`,
-            'echo "test connection succeeded" && exit',
-        ]).run({
+        return await process.run({
             spawnOptions: {
                 env,
             },
         })
-        return result
     } catch (error) {
-        throw new SshError('SSH connection test failed', { cause: error as Error })
+        throw new SshError(process.result()?.stderr ?? 'An unknown error occurred when testing the connection', {
+            cause: error as Error,
+        })
     }
 }