Code Details
| Display code | Navistar Aware SPN 608 FMI 2 |
|---|---|
| SPN | 608 |
| FMI | 2 |
| OEM code | Navistar / International Aware SPN 608 FMI 2 |
| Manufacturer | Navistar / International |
| System | Aware Vehicle Intelligence / Telematics |
| Component | J1587/J1708 data link |
| Source address | Unknown or not applicable |
| Severity | medium |
| Review status | ai source checked |
| Source confidence | high |
| Last reviewed | 2026-03-26 |
Plain-English Meaning
J1587/J1708 is an older vehicle data network used on International trucks before J1939 CAN became the primary standard. The Aware module monitors this network to collect data from modules that still broadcast on J1587/J1708. When no messages arrive for 5 seconds, the fault becomes active. On vehicles with no active J1587/J1708 devices, this may reflect a configuration mismatch rather than a real fault.
Navistar S08312 maps Navistar Aware SPN 608 FMI 2 to J1587/J1708 Datalink — data erratic, intermittent or incorrect at Grey connector Pins 1 and 2. The fault is active when no datalink messages are received for more than 5 seconds while ignition is on and J1587/1708 communication is enabled.
Common Symptoms
- J1587-sourced vehicle data unavailable in the fleet portal
- Aware module diagnostic output shows no J1587 messages received
- Older body or engine parameters may be missing even though J1939 values continue to update
- Fault may appear immediately after installing the module on a newer J1939-only truck
Possible Causes
Possible causes may include the items below. The list is not a parts diagnosis.
- Grey connector Pins 1 and 2 are not connected to an active J1587/J1708 network
- Vehicle does not have active J1587/J1708 devices but the Aware module is configured to monitor that network
- J1587/J1708 wiring to the Aware module is damaged or disconnected
- J1587/J1708 network fault on the vehicle preventing any message transmission
First Checks
- Confirm whether the vehicle has active J1587/J1708 network devices — on newer J1939-only vehicles, the J1587 connection may be unused.
- If J1587/J1708 monitoring is not needed for this vehicle's configuration, review whether it can be disabled in the Aware module setup to prevent the fault.
- If J1587/J1708 monitoring is required, inspect Grey connector Pins 1 and 2 for connection and wiring integrity.
- Check whether other diagnostic tools can read J1587/J1708 messages from the vehicle — if not, the vehicle-side network may be the source.
- Look for recent radio, telematics, liftgate, or body-controller wiring work near the Grey connector; legacy twisted-pair wiring is often disturbed during accessory installs.
Can I Keep Driving?
Severity depends on active status, warning lamps, affected system, and related codes. Stop safely for red stop lamps, brake warnings, oil pressure warnings, high coolant temperature warnings, severe derate, or any abnormal vehicle-control concern.
Related Lookup Pages
Sources
- Navistar Aware Vehicle Intelligence Diagnostic Trouble Codes S08312 Navistar / International Truck Body Builder · oem · accessed 2026-05-05 · confidence high
Source: Navistar / International Truck Body Builder, Navistar Aware Vehicle Intelligence Diagnostic Trouble Codes S08312. This page paraphrases factual fields only and is not a substitute for the original document.
Open source - Navistar Engine Diagnostic Trouble Code Body Builder References Navistar / International Truck Body Builder · oem · accessed 2026-05-05 · confidence medium
Source: Navistar / International Truck Body Builder, Navistar Engine Diagnostic Trouble Code Body Builder References. This page paraphrases factual fields only and is not a substitute for the original document.
Open source
FAQ
Do modern Navistar trucks still use J1587/J1708?
Newer International trucks are primarily J1939 CAN-based. Some older modules, body controller functions, or legacy accessories may still use J1587/J1708. Whether the Aware module should be configured to monitor J1587/J1708 depends on whether any active J1587 devices are present in the specific vehicle.
Can Navistar Aware SPN 608 FMI 2 be disabled if the vehicle has no J1587/J1708 network?
Depending on the Aware module software version, the J1587/J1708 monitoring function may be configurable. Contact Navistar service or the fleet telematics provider to determine whether the monitoring can be disabled for vehicles without an active J1587/J1708 network.
Is there overlap between the data on J1587/J1708 and J1939?
On vehicles that have both networks active, many parameters (vehicle speed, engine RPM, odometer) are broadcast on both. The Aware module typically consolidates data from both sources, preferring J1939 where available. A J1587 fault does not prevent J1939 data collection.