Engine faults related to telematics devices

Learn more about common standard engine and telematics device faults, what they mean, their severity, and how to troubleshoot them.

Important: If you encounter a fault code that is not included in this table, please contact the manufacturer or a professional. While this table includes standard and Geotab-specific fault codes, there exist other proprietary or manufacturer-specific fault codes which are beyond the scope of Geotab.


Fault code	Fault description/meaning	Fault severity	Additional notes	Troubleshooting steps
132	Telematics Device: Firmware Update Applied Successfully	Informational	Device firmware received the expected/indicated version.
130	Telematics device fault: all power removed - device restarted		Device stopped receiving power from the vehicle/asset, then restarted after regaining power.
131	Telematics device fault: low voltage in power supply (bad battery or reinstall required- Device restarted			Check vehicle/asset’s battery voltage, ensure the connection is solid, and check if the device is getting power (at least the red light comes on).
136	Telematics device fault: telematics device has been unplugged		Device was unplugged from the vehicle/asset. No power reached the device until this message was reported.
135	Warning: vehicle battery has low voltage			Check vehicle/asset’s battery voltage, ensure the connection is solid, and check if the device is getting power (at least the red light comes on).
139	Telematics device fault GPS quality poor (bad device install or vehicle undercover)			Check the device and follow the troubleshooting clock to see if the blue light comes on the device.
166	ALERT: Accident limit for acceleration exceeded		Related to possible collision or loose/weak connection from the GO device to the vehicle/asset.
140	Telematics device fault: remove device and report to reseller - GPS module not responding			Contact Support.
145	Telematics device fault: remove device and report to reseller - GPS antenna unplugged			Contact Support.
147	Telematics device fault: problem communicating with engine - potential bad install - harness issue or device failure - CAN mode failed during normal operation			Verify the device install and ensure it is secured with all needed zip ties. The red light must be illuminated when starting the vehicle/asset. All three lights must eventually light up.
172	Excessive accelerometer events			Verify the device install and ensure it is secured with all needed zip ties. The red light must be turned on when starting the vehicle/asset. All three lights must eventually light up.
174	Excessive accelerometer events over accident threshold			Verify the device install and ensure it is secured with all needed zip ties. The red light must be illuminated when starting the vehicle/asset. All three lights must eventually light up.
175	Low priority warning light on		The fault read from the vehicle is a low priority and not critical.	For more information, use an official Scantool/Diagnosis machine from the manufacturer.
478	Fault - variable length data logging turned off due to excessive data			Verify the device install and ensure it is secured with all needed zip ties. The red light must be illuminated when starting the vehicle/asset. All three lights must eventually light up.
466	Fault - engine hours stale		The fault read from the vehicle is related to the ECU not transmitting Engine hours info. There is nothing to be done	but for more information, use an official Scantool/Diagnosis machine from the manufacturer.
265	Telematics device fault: check device install - accelerometer disabled due to excessive data			Verify the device install and ensure it is secured with all needed zip ties. The red light must be illuminated when starting the vehicle/asset. All three lights must eventually light up.
281	Accelerometer calibration in progress (more driving required)		Device is still determining its spatial orientation inside the vehicle/asset for axis assignment (x, y, z).
287	Telematics device fault: problem communicating with engine - potential bad install - harness issue or device failure - excessive errors detected on the CAN BUS and it is now in only listen mode			Verify the device install and ensure it is secured with all needed zip ties. The red light must be illuminated when starting the vehicle/asset. All three lights must eventually light up.
290	Telematics device fault low voltage in power supply (bad battery or reinstall required) Device restarted			Check the vehicle battery and ensure the device is getting power (red light comes on).
491	Proprietary OEM fault, description unavailable		The fault read from the vehicle is not standard.	For more information, use an official Scantool/Diagnosis machine from the manufacturer.
—	Diesel particulate filter soot load regeneration threshold		Shows how much soot (as a percentage) there is on the Diesel particulate filter.
488	Telematics device fault: remove device and report to reseller - SWC chip failure	Warning	Possible hardware failure of the SWC CAN transceiver	Initial Checks: Visit the Measurements page in MyGeotab. Diagnostic Procedures: Check if the device is still reporting engine data. When to seek professional help: If the device stopped reporting engine data around the time of the fault.
616	Telematics device fault: Collision data is unavailable for 10 minutes due to excessive logging of Collision events. If this fault occurs three consecutive times then the GO device disables logging any suspected Collisions until the device is reset.	Warning	Collision IMU channel has exceeded its log limit and has paused logging on this channel for a short period.	Initial Checks: Visit the Measurements page in MyGeotab. Diagnostic Procedures: Check if the device is recording accurate accelerometer data. Take note if the vehicle has been driving off road more often than usual. Potential Solution/Fixes: Verify device installation. A loose install may result in erroneous collision events. When to seek professional help: If it has been verified that the device install is secure and is not in an environment prone to excessive vibration, or if the issue began following a firmware update.
130	Telematics device fault: All power removed and device restarted	Informational		Initial Checks: Did the device lose power unexpectedly? Diagnostic Procedures: Confirm if the device was power cycled at this time. The fault will be recorded when the device powers back up. Potential Solution/Fixes: Check for unexpected power resets. These could be caused by a loose install, power supply issue, kill switch, or unplug of the device. When to seek professional help: If the device is reporting excessive reset faults and common causes of power issues have been ruled out as the cause.
136	Telematics device fault: Telematics device is unplugged	Informational		Initial Checks: Was the device recently unplugged? Diagnostic Procedures: Confirm if the device was power cycled at this time. The fault will be recorded when the device lost power but won't be sent to MyGeotab until the device reconnects. Potential Solution/Fixes: Check for unexpected power resets. These could be caused by a loose install, power supply issue, kill switch, or unplug of the device. When to seek professional help: If the device is reporting excessive unplugged faults and common causes of power issues have been ruled out as the cause.
477	Telematics device fault: Disabled due to production test firmware	Informational	This fault is expected to be reported upon first install during the provisioning process. Once the device is fully set up and provisioned (updated to stable firmware), this fault should not be reported any more.	Initial Checks: Was the device recently installed for the first time? Diagnostic Procedures: Check the timestamp of when the fault was recorded. If the device was still provisioning during this time then the fault is expected. Potential Solution/Fixes: Ensure the device finishes provisioning. When to seek professional help: If the device reports this fault after provisioning has been completed and the device is on at least the latest Stable firmware.
134	Telematics device fault: report to reseller - device restarted (internal reset condition)	Informational	Fault other reset	Initial Checks: Did the device lose power unexpectedly? Diagnostic Procedures: Confirm if the device was power cycled at this time. The fault will be recorded when the device powers back up. Potential Solution/Fixes: Check for unexpected power resets. These could be caused by a loose install, power supply issue, kill switch, or unplug of the device. When to seek professional help: If the device is reporting excessive reset faults and common causes of power issues have been ruled out as the cause.
135	Warning: Vehicle battery has low voltage	Warning		Initial Checks: Check the voltage data in MyGeotab under Measurements. When to seek professional help: Consult a mechanic or technician to diagnose the health of the vehicle battery.
133	Telematics device fault: report to reseller - telematics device restarted (internal watchdog condition)	Informational	Internal watchdog condition. This needs to be reviewed by engineering.	Contact Support.
287	Telematics device fault: problem communicating with engine - potential bad install - harness issue or device failure - excessive errors detected on the CAN BUS and it is now in listen only mode	Warning	Device will go into listen-only mode. Any request-based engine data will be lost (most OBD-II data).	Initial Checks: Verify the install is secure and that there are no other third party devices connected. Diagnostic Procedures: Try swapping out the device or harness (if applicable). Potential Solution/Fixes: Device power cycle can allow the device to recover. When to seek professional help: Contact Support if the problem persists.
491	Telematics device fault: Single Wire CAN (SWC) fuse blown	Warning	SWC fuse is blown. Note that if the vehicle doesn't rely on SWC protocol for data, then the device will still function and operate.	Initial Checks: Visit the Measurements page in MyGeotab. Diagnostic Procedures: Check if the device is still reporting engine data. When to seek professional help: If the device stopped reporting engine data around the time of the fault.
175	Low priority warning light is on	Informational		Initial Checks: Visit the Faults page in MyGeotab. Diagnostic Procedures: Verify that the low priority engine light is illuminated on the vehicle's dash. Potential Solution/Fixes: Consult a mechanic or technician.
168	Vehicle warning light is on	Informational		Initial Checks: Visit the Faults page in MyGeotab Diagnostic Procedures: Verify that the warning light is illuminated on the vehicle's dash. Check for relevant fault codes recorded around the same time. Potential Solution/Fixes: Consult a mechanic or technician.
265	Telematics device fault: Check device installation as the accelerometer was disabled due to excessive data	Warning	The Strike and Probation system added in firmware version x.40 should reduce the likelihood of a device exceeding the acceleration limit in most normal driving scenarios.	Initial Checks: Visit the Measurements page in MyGeotab. Diagnostic Procedures: Check if the device is recording accurate accelerometer data. Take note if the vehicle has been driving off road more often than usual. Potential Solution/Fixes: Verify device installation. A loose install may result in excessive accelerometer data recorded. When to seek professional help: If it has been verified that the device install is secure and is not in an environment prone to excessive vibration, or if the issue began following a firmware update.
615	Telematics device fault: Harsh Event data is unavailable for 10 minutes due to excessive logging of Harsh Events. If this fault occurs three consecutive times then the GO device disables logging any suspected Harsh Events until the device is reset.	Warning		Initial Checks: Visit the Measurements page in MyGeotab. Diagnostic Procedures: Check if the device is recording accurate accelerometer data. Take note if the vehicle has been driving off road more often than usual. Potential Solution/Fixes: Verify device installation. A loose install may result in excessive accelerometer data recorded. When to seek professional help: If it has been verified that the device install is secure and is not in an environment prone to excessive vibration, or if the issue began following a firmware update.
292	Telematics device fault: internal reset initiated	Informational	Device will brownout at approximately ~7-8 V. Possible causes: Device master switch is reset Certain Feature Flags (FF) enabled Remote scan tool resets the device	Initial Checks: Did the device lose power unexpectedly? Diagnostic Procedures: Confirm if the device was power cycled at this time. The fault will be recorded when the device powers back up. Potential Solution/Fixes: Check for unexpected power resets. These could be caused by a loose install, power supply issue, kill switch, or unplug of the device. When to seek professional help: If the device is reporting excessive reset faults and common causes of power issues have been ruled out as the cause.
282	Telematics device fault: problem communicating with engine - potential bad install - harness issue or device failure - CAN BUS disabled due to excessive errors detected	Warning
128	Telematics device fault: remove device and report to reseller - flash memory failure	Critical	Hardware failure of the flash memory.	Contact Support.
140	Telematics device fault: remove device and report to reseller - GPS module not responding	Warning	No messages received from the GPS chipset for 30s. The device should recover from this on its own, but if it doesn't, this fault can possibly indicate a hardware failure.	Initial Checks: Check trips history for straight lines on the map or breadcrumb trail not displaying as expected. Diagnostic Procedures: Did the device recover on its own? If the problem persists, follow the standard device troubleshooting process for GPS issues. When to seek professional help: Device is not tracking trips correctly and standard GPS troubleshooting has been completed. In this case, contact Support as the device may require replacement.
129	Telematics device fault: remove device and report to reseller - internal clock stopped	Critical	Possible hardware failure of the internal clock	Initial Checks: Was the device recently installed for the first time? Diagnostic Procedures: Check the timestamp of when the fault was recorded. If the device was still provisioning during this time then the fault may be expected (if on x.0.57 or x.0.60 firmware). Potential Solution/Fixes: Ensure the device finishes provisioning. When to seek professional help: If this fault is recorded after a device has finished provisioning, contact Support
297	Telematics device fault: remove device and report to reseller - RAM memory failure	Critical	Hardware failure of the device RAM.	Contact Support.
166	Alert: Collision limit for acceleration exceeded	Informational		Initial Checks: Confirm whether or not the vehicle was in a collision, or if the device recently had its installation modified. Potential Solution/Fixes: If an erroneous collision event was detected, verify the device installation. When to seek professional help: If the vehicle was not in a collision and the installation of the device is confirmed to be secure.
281	Accelerometer calibration in progress (more driving required)	Informational	The following are required to calibrate: Harsh driving event Valid GPS Stable acceleration in the Z axis (~9.81 m/s^2)	Initial Checks: Accelerometer calibration requires some trips to complete. Ensure the vehicle has been driven. Diagnostic Procedures: Valid GPS and stable orientation is required. Verify the device is installed securely and has a clear view of the sky. Accelerometer calibration will occur after each power cycle. When to seek professional help: If the device has not calibrated accelerometer over multiple trips.
461	Network communication fault codes detected - potential causes include bad install or issue with device harness or vehicle	Informational	Logged when Geotab receives a network code (U code) from the vehicle.	Initial Checks: A network fault code (U-code) was detected by the device. Check the faults page in MyGeotab to see if a vehicle fault was reported. Diagnostic Procedures: Isolate the cause of the network code. Does the fault go away when the GO device is unplugged? Try swapping out the GO device or harness (if applicable). If the issue persists contact a mechanic or technician for further diagnosis. When to seek professional help: If the issue goes away when the GO device is unplugged, contact Support.
478	Fault: Variable length data logging turned off due to excessive data	Informational	Logged when variable length records are disabled due to excessive logging.	Contact Support.
377	Device reset due to parameter change	Informational	Logged when the device is manually reset after device parameters were updated.
462	GPS config retry fail	Critical		Initial Checks: Check trips history for straight lines on the map or breadcrumb trail not displaying as expected. Diagnostic Procedures: Did the device recover on its own? If the problem persists, follow the standard device troubleshooting process for GPS issues. When to seek professional help: Device is not tracking trips correctly and standard GPS troubleshooting has been completed. In this case, contact Support as the device may require replacement.
298	GPS failure fault	Critical	Logged when the device fails to get the GPS version after more than 5 attempts. Also logged when One Time Programming has failed after more than 10 attempts (PHX only).	Initial Checks: Check trips history for straight lines on the map or breadcrumb trail not displaying as expected. Diagnostic Procedures: Did the device recover on its own? If the problem persists, follow the standard device troubleshooting process for GPS issues. When to seek professional help: Device is not tracking trips correctly and standard GPS troubleshooting has been completed. In this case, contact Support as the device may require replacement.
284	Status data no longer being saved to the accident log due to excessive data	Informational	Logged when accident data is disabled due to excessive logging. The threshold is 300 logs in 10 minutes	Contact Support.
197	Device is disabled in MyAdmin (contact reseller)	Informational	Logged when the device subscription has been Suspended or Terminated.	Initial Checks: Confirm device is on an active rate plan. Potential Solution/Fixes: Put the device onto an active rate plan. When to seek professional help: If the device has been on an active rate plan for more than 24 hours and the fault persists, contact Support.
449	Log data buffer overrun	Warning	Logged when the log buffer wraps, indicates potential data loss.	Initial Checks: Check to see if the device was out of cellular coverage for multiple days. Potential Solution/Fixes: Ensure the device is operating in an area of good connectivity. When to seek professional help: If the device is operating in an area of good connectivity and reports this fault.
289	Telematics device fault: serious problem communicating with engine - safety issue - remove device immediately - CAN BUS short detected	Critical	Fault specific to GO7/8 devices only, does not apply to GO9 or newer. Logged when 6-pin harness is detected, but engine data is not received for 5 minutes after ignition.
174	Excessive accelerometer events over collision threshold	Warning	Default IMU Channel exceeded its separate accident-level log limit and is fully disabled. Logging of accident-level accelerometer events will remain disabled until the next device reset. The Default Channel tracks the log count of accident-level events separately from nominal-level events to help ensure that accident-level events are not lost due to the log limit being reached. Note: this behavior is separate and distinct from the Collision IMU Channel.	Initial Checks: Visit the Measurements page in MyGeotab. Diagnostic Procedures: Check if the device is recording accurate accelerometer data. Take note if the vehicle has been driving off road more often than usual. Potential Solution/Fixes: Verify device installation. A loose install may result in excessive accelerometer data being recorded. When to seek professional help: If it has been verified that the device install is secure and is not in an environment prone to excessive vibration, or if the issue began following a firmware update.
296	Telematics device fault: internal stack error	Informational	Logged as an osError when an internal stack error occurs.	Contact Support.
487	Telematics device fault: IOX power permanently disabled	Critical	Logged when IOX power fault persists for 22m45s, and power to IOX is permanently disabled.	Initial Checks: Verify what IOXs are installed. Diagnostic Procedures: Ensure total IOX current draw doesn't exceed GO device IOX max limit (2750mA for the GO9). Potential Solution/Fixes: Power cycle will allow the device to recover. When to seek professional help: If the fault persists, contact Support or a certified installer.
463	Telematics device fault: IOX-Battery power overcurrent condition	Warning	Logged when an IOX overcurrent condition is detected.	Initial Checks: Verify the IOX-Battery is installed and has no physical damage. Diagnostic Procedures: Ensure total IOX current draw doesn't exceed GO device IOX max limit (2750mA for the GO9). When to seek professional help: If the fault persists, contact Support or a certified installer.
490	Telematics device fault: IOX-Battery power permanently disabled	Critical	Logged when IOX power fault persists for about 3 minutes, causing power to remaining IOXs down the daisy chain to be permanently disabled.	Initial Checks: Verify the IOX-Battery is installed and has no physical damage. Diagnostic Procedures: Ensure total IOX current draw doesn't exceed GO device IOX max limit (2750mA for the GO9). Potential Solution/Fixes: Power cycle will allow the device to recover. When to seek professional help: If the fault persists, contact Support or a certified installer.
290	Telematics device fault: Low voltage power supply (bad battery or reinstallation required) and device restarted	Warning	Logged when a brown-out reset caused by an external pin is detected.	Initial Checks: Check the voltage data in MyGeotab under Measurements. Diagnostic Procedures: Confirm if the device was power cycled at this time. The fault will be recorded when the device powers back up. Potential Solution/Fixes: Check for unexpected power resets. These could be caused by a loose install, power supply issue, kill switch, or unplug of the device. When to seek professional help: If the device is reporting excessive reset faults and common causes of power issues have been ruled out as the cause.
614	Telematics device fault: Odometer source changed	Informational	This fault log is saved when the odometer source used for reporting the status log is changed. It can happen when the current odometer source is deemed invalid by the GO firmware logic and an alternate odometer source is available on the vehicle.	Initial Checks: Check the odometer data in MyGeotab under Measurements. When to seek professional help: If the odometer data looks incorrect.