JCB Excavator 656 Fault Code: Loss Of High Speed Tracking
Loss Of High Speed Tracking · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
Fault code 656 on JCB excavators indicates a loss of high speed tracking, meaning the machine will not shift into or hold the high speed travel range. JCB directs technicians to test track motor speeds and pressure switches to isolate the cause.
Medium severity. This is not an immediate safety shutdown code, but it limits travel speed and should be diagnosed before continued heavy use, especially if the machine is relied on for site-to-site travel.
What does JCB Excavator error code 656 mean?
Fault code 656 means the excavator's track drive is not achieving or maintaining high speed tracking mode. High speed tracking is a two-speed function on the track motors, controlled by a pilot pressure signal that shifts the motor from low gear (high torque) to high gear (high speed).
When this fault is present, the machine may stay stuck in low gear, travel slower than expected, or fail to display the high speed indicator ('hare' symbol) even when high speed is selected. This affects productivity and travel time but is primarily a hydraulic/mechanical shift issue rather than a structural safety failure.
JCB's guidance for this code focuses on two checks: confirming actual track motor speed and confirming the pilot pressure signal and pressure switch operation that commands the gear shift.
Common causes of 656
- A track motor that is not shifting into high gear due to a hydraulic or mechanical fault at the motor.
- A faulty or misadjusted pressure switch used to signal high gear selection.
- Insufficient or absent pilot pressure at the pilot port that selects high gear on the track motor.
- A failure in the electrical or hydraulic signal path that prevents the 'hare' symbol from displaying or the shift from occurring.
How to troubleshoot JCB Excavator 656: first checks
- Select high speed tracking and observe whether the 'hare' symbol is displayed on the monitor as expected.
- Test and compare track motor speeds side to side to confirm both motors are shifting equally.
- Check the pressure switches associated with high gear selection for correct operation and wiring condition.
- Measure the pressure at the pilot port that selects high gear on the track motor when high speed is selected, and compare left and right sides.
- Inspect connectors and wiring to the pressure switches for corrosion, looseness, or damage before condemning any component.
How the code clears
No separate clearing step or reset procedure is listed for this code. Diagnosis centers on testing track motor speeds and pressure switches; once the underlying pilot pressure or switch fault is corrected, the high speed tracking function should return to normal operation.
Frequently asked questions
What does JCB fault code 656 mean?
It means the excavator has lost high speed tracking. The track motors are not shifting into or holding the high speed range as commanded.
Why won't my JCB excavator go into high speed travel?
JCB lists two main checks: track motor speed and the pressure switches controlling the high gear shift. A problem with either can prevent the machine from reaching high speed tracking.
What is the 'hare' symbol on a JCB excavator display?
It is the on-screen indicator that shows high speed tracking has been selected. If it does not appear when you select high speed, that points toward a fault in the shift circuit rather than just a slow machine.
Is fault code 656 dangerous to keep operating with?
It is not flagged as an immediate safety shutdown fault, but running with reduced or absent high speed tracking limits travel performance. It should be diagnosed and repaired rather than ignored long term.
How do I check the pilot pressure for high gear on the track motor?
With high speed tracking selected, check the pressure at the pilot port that selects high gear on the track motor. Compare readings between the left and right track motors to spot a one-sided fault.
Can a bad pressure switch cause code 656?
Yes. JCB specifically lists testing the pressure switches as one of the two main diagnostic steps for this fault, alongside testing track motor speeds.