Engine fault codes and vehicle health

See the engine fault codes (DTCs) your vehicles report, how severity is decided, turn faults into work orders automatically and get alerts.

For admins · Español

What the Vehicle health page is for

Modern engines store fault codes (also called DTCs, diagnostic trouble codes) when a sensor or system reports a problem, and they light a warning lamp on the dash. When the ELD device can read those codes, EZ Logs collects them so you can see which trucks need attention before a small problem becomes a breakdown.

Open it from Drivers & fleet > Vehicle health. It has three views:

The Vehicles page also shows a badge such as 2 engine faults next to each unit with active faults; select it to open the unit's faults.

Important: Engine fault codes are maintenance information. They are not ELD malfunctions (49 CFR 395.34), they never change a driver's logs or hours of service, and they are not shown to an officer at roadside. ELD malfunctions and data diagnostics are covered in HOS violations and compliance status.

Note: Engine faults is an optional feature (Engine faults & vehicle health). If you do not see Vehicle health, the feature is not turned on for your company. Contact EZ Logs support to enable it.

Who can do what

• Owner and Carrier admin: everything (create work orders from faults, change the settings).
• Support (read-only): sees every page, but the buttons are hidden.
• Drivers see a simple vehicle health light on the ELD tab of the app. See The vehicle health light.

Kinds of fault codes

Trucks and cars report faults in two different ways:

• J1939 (heavy-duty trucks): a fault is an SPN (suspect parameter number: which part or value is affected, for example SPN 110 is engine coolant temperature) plus an FMI (failure mode identifier, 0 to 31: what is wrong with it, for example FMI 0 means "data valid but above normal operational range, most severe level"). The page shows it as SPN 110 · FMI 0. Each engine computer (ECU) reports its own list, so the fault sheet also shows the ECU source address (0 is usually engine #1).
• OBD-II (light-duty vehicles and some medium-duty trucks): a fault is a five-character code such as P0420. The first letter is the system (P powertrain, C chassis, B body, U network). Codes starting with P0 and P2 are generic codes with standard titles (SAE J2012), so EZ Logs shows the title, for example "Catalyst system efficiency below threshold (Bank 1)". Codes starting with P1 are manufacturer-specific: look them up in the manufacturer's service information.

Note: The names of J1939 SPNs come from the SAE J1939 Digital Annex, a licensed database. EZ Logs always shows the FMI meaning, but for most SPNs the name shows as Not available until a licensed SPN database is connected. Your repair shop's diagnostic software shows the full name.

How severity works

EZ Logs gives every fault one of three severities:

A fault keeps the highest severity it reached, even if the lamp later goes off.

Critical faults can mean the engine is at risk of damage. Contact the driver and have the truck checked before it continues.

Active and cleared faults

• A fault is Active while the vehicle keeps reporting it.
• It is Cleared when the vehicle reports its fault list again without that code (for example after a repair, or when a technician clears the codes). The History tab lists cleared faults, newest first. Use Load more faults for older ones.
• If the same code comes back later, it is a new fault with its own first seen time, so you can see how often a problem repeats.

The fault sheet

On a vehicle's faults page, select a code to open the fault sheet. It shows:

• The code, its title and, for J1939, the FMI meaning.
• Severity, State and the Lamps that were on.
• First seen, Last reported and Cleared times, Times reported, and the ECU occurrence count when the vehicle sends one.
• Odometer when first seen.
• The vehicle's work orders and inspections (DVIRs) from about a week before and after the fault, so you can see if a driver already reported the problem.

Create a work order from a fault

This needs the Maintenance feature. See Maintenance and work orders.

1. Open the fault sheet.
2. Select Create work order.
3. If the vehicle already has an open engine-fault work order, the fault is added to it instead of creating a second one. Otherwise a new work order is created with the code in its title and a priority from the severity.
4. The sheet then shows Linked to WO-…. Select it to open the work order and add parts, labor or a vendor.

Automatic work orders

1. Go to Vehicle health and select Settings.
2. Under Automatic work orders, choose:
   • Off (the default): you create work orders yourself.
   • Critical faults: new critical faults create a work order.
   • Critical and warning faults: new critical and warning faults create a work order.
3. Select Save settings.

As with the button, a new fault is added to the vehicle's open engine-fault work order when there is one.

Alerts for engine faults

To be told about new faults, add an alert rule (this needs the Alerts feature, see Alerts and geofences):

1. Go to Alerts > Alert rules and select New rule.
2. In Rule type, choose Engine fault.
3. In Lowest fault severity, choose Critical only, Warning and critical or Every new fault.
4. Choose the vehicles, recipients and channels, then save.

The rule fires when a vehicle reports a new fault at or above that severity, and again when an active fault becomes more severe. In the alerts inbox, the alert has a Fault … button that opens the fault sheet. The EZ Logs Fleet app shows the same alerts as push notifications.

Which devices report fault codes

Fault codes reach EZ Logs only when the ELD device sends them. Support for the Pacific Track PT30 is in progress: the PT30 has not yet been seen sending fault codes, and decoding them needs a specification from the device vendor or captures from a truck with an active fault. Until then, PT30-equipped vehicles show no faults on this page. This does not affect the ELD functions of the PT30.

Related pages

• Maintenance and work orders
• Alerts and geofences
• Reviewing DVIRs and certifying repairs