Diagnostic trouble codes (DTCs) are fault codes stored by a vehicle’s Engine Control Module (ECM) when it detects a problem. Reveal reads these codes and alerts you so you can address maintenance issues before they lead to breakdowns.

Link to Reveal: Alerts

What is a diagnostic trouble code?

A DTC is a standardized code that identifies a specific vehicle fault. When the ECM detects a problem (such as an engine misfire, sensor failure, or emissions issue) it stores a DTC. This is the same code a mechanic reads with a diagnostic scanner, and it triggers the check engine light on the vehicle dashboard.

Reveal captures active DTCs via ECM and displays them on Live Map and in the vehicle profile.

Viewing active DTCs on Live Map

The Diagnostics and data panel on Live Map shows the number of active DTCs for a selected vehicle.

To view active DTCs:

1. Go to Live Map.
2. Select a vehicle from the vehicle list or click a vehicle icon on the map.
3. In the vehicle balloon, click More details.
4. on the Diagnostics and data panel, find the Diagnostic trouble code row.
5. To view code details, click the active DTC count.

Setting up a DTC alert

Set up a DTC alert to receive an email notification when a vehicle produces a new diagnostic trouble code. This helps you stay ahead of maintenance issues.

To set up a DTC alert:

1. Go to Alerts.
2. Click CREATE ALERT.
3. Enter an alert name in the Alert name field.
4. Under Alert types, click the Fleet health tab.
5. Select Diagnostic trouble code as the alert type.
6. Click CONTINUE.
7. Configure which vehicles or groups the alert applies to.
8. Determine times and frequency.
9. Set notification preferences (email recipients).
10. Click SAVE.

Understanding DTC alert emails

When a DTC alert is triggered, you receive an email containing:

• Vehicle name and identifier.
• Date and time the DTC was detected.
• DTC code and description.
• Vehicle location at the time of detection.

Use this information to prioritize which vehicles need immediate attention.

Viewing DTC history

Reveal stores a history of all DTCs detected for each vehicle. Use DTC history to identify recurring issues or verify that a fault has been resolved.

To view DTC history:

1. In the navigation bar, click your account profile icon.
2. Go to Admin > Fleet and device list > Select vehicle > Click the three dots in the Actions column > View vehicle.
3. Click the DTC History tab.

The DTC History tab shows all past and current diagnostic trouble codes for the vehicle, including when each was first detected and when it was cleared.