# Altitude Hold Reject, No GPS, with LPE and TeraRanger One **URL:** \ **Category:** PX4 Autopilot\ **Created:** [April 3, 2017, 2:15pm UTC](https://discuss.px4.io/t/altitude-hold-reject-no-gps-with-lpe-and-teraranger-one/2919 "2017-04-03T14:15:36Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![kholdcro](https://discuss.px4.io/letter_avatar_proxy/v4/letter/k/d2c977/32.png) [@kholdcro](https://discuss.px4.io/u/kholdcro)\ **Post date:** [April 3, 2017, 2:15pm UTC](https://discuss.px4.io/t/altitude-hold-reject-no-gps-with-lpe-and-teraranger-one/2919/1 "2017-04-03T14:15:37Z")
Hi everyone, Relatively new user here. I’m struggling to get my drone into Altitude Hold mode with LPE and the TeraRanger One. Every time I try to enter Altitude mode, I’m greeted by red angry text saying “FCU: REJECT ALTITUDE CONTROL”. I have LPE\_Fusion set to 114, which corresponds to _fuse optical flow, fuse land detector, pub agl as lpos down,_ and _flow gyro compensation_. Is this correct? Is there any documentation that could give me further insight as to what each of these options mean? I have SENS\_EN\_TRONE enabled and get reasonable data when observing DISTANCE\_SENSOR.current\_distance. This tells me that the TeraRanger is correctly connected to the PixRacer. Is there anything I’m visibly doing wrong? The TeraRanger seems to be working properly based on the `[lpe] lidar init` in logs below, but still, ALTITUDE mode is being rejected. Any ideas? `[INFO] [1491228079.209893317]: FCU: ARMED by RC [INFO] [1491228079.305117743]: FCU: [blackbox] /fs/microsd/log/2017-04-03 [INFO] [1491228079.382647661]: FCU: [blackbox] recording: 14_01_19.px4log [INFO] [1491228083.303011893]: FCU: Takeoff detected [INFO] [1491228084.253442406]: FCU: [lpe] land timeout [INFO] [1491228085.154338476]: FCU: [lpe] lidar init: mean 36 cm stddev 6 cm [ERROR] [1491228090.855884293]: FCU: REJECT ALTITUDE CONTROL [ERROR] [1491228092.303381943]: FCU: REJECT ALTITUDE CONTROL [ERROR] [1491228094.505401458]: FCU: REJECT ALTITUDE CONTROL [ERROR] [1491228102.554002028]: FCU: REJECT ALTITUDE CONTROL [INFO] [1491228105.803464174]: FCU: DISARMED by RC [INFO] [1491228106.352484994]: FCU: [lpe] land init [INFO] [1491228106.905136348]: FCU: [lpe] lidar timeout [INFO] [1491228107.055499528]: FCU: [blackbox] stopped (2592 drops) [INFO] [1491228107.355524766]: FCU: Landing detected` Also, just so you know, the end goal is to get PX4Flow working. I assume that it isn’t working properly, as it doesn’t seem to incorporate data into the external range sensor. Thanks in advance! ---
**Author:** ![kholdcro](https://discuss.px4.io/letter_avatar_proxy/v4/letter/k/d2c977/32.png) [@kholdcro](https://discuss.px4.io/u/kholdcro)\ **Post date:** [April 3, 2017, 2:53pm UTC](https://discuss.px4.io/t/altitude-hold-reject-no-gps-with-lpe-and-teraranger-one/2919/2 "2017-04-03T14:53:32Z")
I think the FCU is borked. I’m going to attempt to rewire the TeraRanger to a new drone. I’ll let you know how it goes.