SQL Server Prepared Statement saying invalid column count - php

Question

So I'm working on this project here and I"m trying to do a prepared statement so I can handle any odd objects like slashes and what not as the raw data comes through. However, when I go to execute the statement it provides the same error over and over again:
SQLSTATE: 07002
code: 0
message: [Microsoft][SQL Server Native Client 11.0]COUNT field incorrect or syntax error
it says that my field count is incorrect, but I checked all the variables and made sure everything that was supposed to be there, is. So I'm just a little confused I guess. Also to note this is my first time working with the sqlsrv prepared statements, so any help would be awesome!
Here is my code below:
<?php
$serverName = "localhost";
$connectionInfo = array( "Database"=>"devel", "UID"=>"root", "PWD"=>"");
$conn = sqlsrv_connect( $serverName, $connectionInfo);
$error_message = "";
$xml = trim(file_get_contents('/file.xml'));
$xml = new SimpleXMLElement($xml);
$truck_number;
$date_time;
$speed;
$heading;
$gps_quality;
$latitude;
$longitude;
$location;
$fix_type;
$ignition;
$gps_odometer;
$gps_rolling_odometer;
$performx_odometer;
$performx_fuel;
$performx_speed;
$performx_idle;
$packet_id;
sqlsrv_begin_transaction($conn);
$error_count = 0;
$q = "INSERT INTO eagle_devel.dbo.people_net (truck_number, date_time, speed, heading, gps_quality, latitude, longitude, location, fix_type, ignition, gps_odometer, gps_rolling_odometer,
performx_odometer, performx_fuel, performx_speed, performx_idle, packet_id) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";
$stmt = sqlsrv_prepare($conn, $q, array(&$truck_number, &$date_time, &$speed, &$heading, &$gps_quality, &$latitude, &$longitude, &$location, &$fix_type, &$ignition, &$gps_odometer, &$gps_rolling_odometer, &$performx_odometer, &$performx_fuel, &$performx_speed, &$performx_idle, &$packet_id));
foreach($xml->loc_history as $loc_history){
$truck_number = $loc_history->truck_number;
$date_time = $loc_history->datetime;
$speed = $loc_history->speed;
$heading = $loc_history->heading;
$gps_quality = $loc_history->gps_quality;
$latitude = $loc_history->latitude;
$longitude = $loc_history->longitude;
$location = $loc_history->location;
$fix_type = $loc_history->fix_type;
$ignition = $loc_history->ignition;
$gps_odometer = $loc_history->gps_odometer;
$gps_rolling_odometer = $loc_history->gps_rolling_odometer;
$performx_odometer = $loc_history->performx_odometer;
$performx_fuel = $loc_history->performx_fuel;
$performx_speed = $loc_history->performx_speed;
$performx_idle = $loc_history->performx_idle;
$packet_id = $xml->packet_id;
if(sqlsrv_execute($stmt) === false){
$error_count++;
if(($errors = sqlsrv_errors()) != null){
foreach($errors as $error){
$error_message .= "SQLSTATE: ".$error['SQLSTATE']."<br>";
$error_message .= "code: ".$error['code']."<br>";
$error_message .= "message: ".$error['message']."<br><br>";
}
}
}
}
if($error_count)
sqlsrv_rollback($conn);
else
sqlsrv_commit($conn);
print $error_message;
?>
UPDATE : I was told to try and initialize the variables before hand so I did and I get this.
SQLSTATE: IMSSP
code: -16
message: An invalid PHP type for parameter 1 was specified.
I have no idea what this means so I'm researching.