Creality CR Touch Not Probing: Diagnosis and Fixes

A creality cr touch not probing complaint usually describes one of three machines: the LED flashes red and the pin never drops, the pin drops but the carriage keeps descending as if nothing triggered, or the mesh dies part way through with a probing error. Those are different faults, and the order you check them matters: a firmware reflash will not cure a bent pin, and a new probe will not cure a swapped wire.

Read the probe before you touch anything

Creality’s own checklist for the “CR-Touch error” on the Ender-3 V3 SE is short. The fault analysis page calls it a “CR-touch Self-check Abnormality” and says to check “whether the red light is flashing / there is no light flashing” and “whether the probe can be probed normally twice after the machine is turned on.” A healthy probe cycles its pin twice at power-on and settles to steady blue. Flashing red is an alarm. No light is a power problem, not a probe problem.

The CR Touch speaks the BLTouch servo-angle protocol, which is why Marlin runs it under the BLTOUCH define and Klipper under [bltouch], but it is not the same sensor. Creality’s product page describes a metal probe and a “light-triggered” normally-open switch, where Marlin’s probe documentation describes the BLTouch as a Hall-effect sensor watching a magnetic pin. Most BLTouch advice transfers; the Allen-key core trick does not.

One reading that fools people: Marlin’s M119 docs note that “the BLTOUCH probe only sends a brief pulse, so TRIGGERED indicates the probe is in error state.” A z_probe: TRIGGERED at idle means alarm, not “working”.

Cause 1: the pin is stuck or bent

Symptom: red flash at self-check, or the mesh stalls after a few points with the pin retracted. An Ender 3 V2 thread on Creality’s forum describes exactly that, stuck around the third point with the LED flashing red. Creality Support’s reply: re-plug the probe cable and, powered off, press the probe tip for 10 seconds. Others cleared it with the menu self-test or by cycling the pin by hand. If the pin is visibly bent, which the DREMC install guide lists as the first flashing-red cause, replace the probe. A straightened pin drags in the housing and the alarm comes back.

Cause 2: wiring, connector and the ribbon cable

Creality has not kept the wire colour order consistent across CR Touch batches. The Duet3D forum’s CR Touch thread opens with an owner who destroyed a probe on swapped wires, and the Duet maintainer confirms “what hasn’t been consistent is the wiring colour/order Creality use.” Verify the pinout from the probe, not the colours. On a 4.2.2 board the five wires land on the probe header as G, V, IN, G, OUT.

The SE Configuration_adv.h says a probe that is not deploying wants a Reset and Self-Test and then a check of the “BROWN, RED and ORANGE wires” (power and control), while an unrecognised trigger “has been very often because the BLACK and WHITE wires needed to be swapped.” Pin moves but never triggers: signal pair. Pin never moves: power or control pair. ANTCLABS’s V3 page adds that a red LED flashing at 80 percent duty during a print means a power-wire fault.

On the V3 SE, KE and V3 Plus the probe hangs off the toolhead through a ribbon, and Creality’s SE fix is to re-plug the CR Touch and the adapter-board ribbon at both ends. The KE’s error 2194 page lists “CR-touch red light flashing, probe not deploying” as a cause of Z failing to home in self-test; the fix is to re-seat the 30-pin ribbon at both ends. A V3 KE owner tapping the pin with a screwdriver to pass self-check is the same fault.

Cause 3: firmware that does not know a probe exists

The CR Touch kit is sold for the 32-bit 4.2.2 and 4.2.7 boards only, and Creality’s product page tells you to download the CR-Touch firmware and flash it from the SD card. Stock Ender-3 and V2 firmware homes Z on the endstop switch; fit the probe without the firmware and Z homes with the pin retracted, nozzle first.

What the probe build changes, per the Marlin docs: a probe on the Z-min pin needs Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN. Creality’s SE Configuration.h enables that, USE_PROBE_FOR_Z_HOMING, Z_SAFE_HOMING and a 4 x 4 bilinear mesh. The firmware update guide covers the flashing steps.

Cause 4: offsets that send the pin off the plate

If the pin drops over thin air at a bed edge, Marlin drives to Z_PROBE_LOW_POINT, -2 mm below the expected trigger in the SE config, and STOPs. An Ender-3 owner on a 4.2.7 board reported probe points about 1.5 cm right of where they belonged; the moderator’s fix was Configuration > Advanced Settings > Probe Offsets, with the standard Ender-3 values X -45, Y -5. Creality’s SE source carries three different NOZZLE_TO_PROBE_OFFSET sets for different production runs; check yours against the physical probe. Once fixed, Marlin’s M999 docs apply: a failed deploy aborts probing and STOPs, “note that this disables all heaters,” and M999 restarts.

Cause 5: probing faster than the pin can retract

Creality ships the SE with BLTOUCH_HS_MODE on, under Marlin’s own warning: “Danger: Disable if your probe sometimes fails… If the machine can’t raise Z fast enough the BLTouch may go into ALARM.” The rest of the SE probe block: Z_PROBE_FEEDRATE_FAST (10*60) (10 mm/s, with a commented 4 mm/s alternative), slow speed half that, MULTIPLE_PROBING 2, BLTOUCH_DELAY 350 ms, 10 mm deploy clearance, 3 mm between points. A mesh that fails at random points on a tired Z lead screw fits this cause; compile with HS mode off, or drop the fast feedrate to 4*60.

The KE’s Klipper printer.cfg declares speed: 5, lift_speed: 20, probe_with_touch_mode: true and stow_on_each_sample: false, with a 5 x 5 mesh at horizontal_move_z: 8. The Klipper docs warn that stow_on_each_sample: False travels with the pin down, so lost clearance lets the pin catch on a clip.

Reset and test commands

Marlin, from any terminal, using the M280 angles from the ANTCLABS manual:

M280 P0 S160   ; alarm release and pin up
M280 P0 S120   ; self-test, cycles the pin 10 times
M280 P0 S10    ; pin down
M280 P0 S90    ; pin up
M119           ; z_probe should read open with the pin up
M999           ; clear a STOP once the cause is fixed

Klipper (KE, V3 Plus, conversions), from the Klipper docs:

BLTOUCH_DEBUG COMMAND=pin_down
BLTOUCH_DEBUG COMMAND=touch_mode
QUERY_PROBE                      ; expect "probe: open"
QUERY_PROBE                      ; nudge the pin up first: expect "probe: TRIGGERED"
BLTOUCH_DEBUG COMMAND=pin_up
PROBE_ACCURACY

“BLTouch failed to raise probe” is mechanical, back to cause 1. “BLTouch failed to verify sensor state” is the clone check; Klipper says to set pin_up_touch_mode_reports_triggered: False only if the manual test above passes every time and the error persists.

How to verify the fix

1. Power cycle. The pin drops and retracts twice and the LED settles blue, Creality’s own pass condition.
2. M119 or QUERY_PROBE reads open at idle.
3. Home with the fingernail test from the Klipper docs: touch the pin before it reaches the bed and Z must stop; then home again untouched.
4. Run a full mesh: 16 points on the SE, 25 on the KE, no red flash, no STOP.
5. On the SE, read the Z compensation value. Creality’s leveling failure page puts normal values between -1 and -3; -0.04, 0 or -10 means the height calibration failed even though the probe moved.

Then tune the first layer with the Z offset guide and the bed leveling and extrusion tuning post. If the probe is dead and a replacement is days away, fdmdesk’s manual bed leveling walkthrough keeps an Ender-3 printing on the four knobs.

If you own a K1, K1C or K1 Max

There is no CR Touch on the K1 series; leveling is a strain gauge behind the nozzle. Creality’s K1 Max leveling page works from the mesh data: under 3 mm from highest to lowest is normal, over 5 mm with a normal trend means the Z axis needs re-tensioning, and an abnormal trend points at the gauge. Different sensor, different fault tree.

Related across the network

• How to Level a Bed With BLTouch: Marlin and Klipper Guide — printlabguide.com
• Klipper vs Marlin: Which Firmware Should You Run? — klipperlab.com
• How to Calibrate E-Steps on Ender 3 (Step by Step) — printlabguide.com
• Pressure Advance Calibration for Klipper and Marlin — printlabguide.com
• Anycubic Bed Leveling: The Paper Method and Z Offset — anycubicguide.com