Code Details
| Display code | Navistar Aware SPN 444 FMI 3 |
|---|---|
| SPN | 444 |
| FMI | 3 |
| OEM code | Navistar / International Aware SPN 444 FMI 3 |
| Manufacturer | Navistar / International |
| System | Aware Vehicle Intelligence / Telematics |
| Component | Battery backup voltage — above normal |
| Source address | Unknown or not applicable |
| Severity | medium |
| Review status | ai source checked |
| Source confidence | high |
| Last reviewed | 2026-03-26 |
Plain-English Meaning
The Navistar Aware module supports an optional battery backup input that allows it to continue operating when the main vehicle supply is lost. When this backup input is available and powered, the module monitors its voltage. A reading that is erratic, too high, or too low relative to the expected backup battery level triggers this fault.
Navistar S08312 maps Navistar Aware SPN 444 FMI 3 to Battery Backup Potential Voltage — Voltage above normal or shorted high at Black connector Pin 2. The fault only activates when the battery backup is available. If no backup battery is connected, this fault should not be active.
Common Symptoms
- Aware Vehicle Intelligence alert active when a battery backup is connected
- Backup battery voltage reading outside the expected range in Navistar diagnostic software
- Events during key-off or battery disconnect periods may be missing from the fleet record
- Fault may show up after long storage, body shop work, or battery replacement
Possible Causes
Possible causes may include the items below. The list is not a parts diagnosis.
- Backup battery charger circuit providing overvoltage, or incorrect battery connected
- Wiring fault on the backup supply circuit — loose, corroded, or broken connection
- Backup battery connected but not matching the expected voltage specification for the Aware module
- Backup battery fuse or inline protection device open after service work
- Backup battery ground path shared with another accessory and dropping voltage under load
First Checks
- Measure the voltage at Black connector Pin 2 and compare to the backup battery specification.
- If no backup battery is installed, confirm that Navistar Aware SPN 444 FMI 3 is not expected to be active — an open Pin 2 should not trigger the fault unless the module sees a stray voltage there.
- Inspect the backup battery wiring and battery condition.
- Confirm the backup battery specification matches what the Aware module expects.
- Load-test the backup battery rather than relying only on open-circuit voltage; small backup batteries can read normally with no load and collapse when the module wakes up.
- Check whether the fault timestamp follows a battery disconnect, jump-start, or body accessory repair.
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
Is a battery backup required for the Navistar Aware module?
The backup battery input is optional. If it is connected, the Aware module monitors its condition. If it is not connected, this fault should not activate. The backup battery allows the module to continue logging data during vehicle power-off or power interruption events.
Can Navistar Aware SPN 444 FMI 3 appear if Pin 2 is unused?
If Pin 2 is not connected and the module is not configured to expect a backup battery, this fault should not activate. If it does appear with no backup battery installed, check for stray voltage on the Pin 2 circuit from adjacent wiring or a mis-wiring condition.
What happens to Aware data logging when the backup battery fails?
If the backup battery fails or is unavailable, the Aware module will lose power when the main vehicle supply is off. Data recorded before the power loss is typically stored in non-volatile memory, but any events that occur during the power interruption will not be captured.