Fuel Economy Decreased — Possible Fault Codes

Found 2 fault codes associated with fuel economy decreased. Codes are sorted by severity — check STOP ENGINE codes first.

SPN 174 FMI 0

Fuel Temperature

Volvo D13 • Component: Fuel Temperature Sensor / Fuel Cooler • J1939

🟡 CHECK AT NEXT STOP

MID 128 PID 105 FMI 10

Intake Manifold Temperature

PACCAR MX-13 • Component: Intake Manifold Temperature Sensor • J1587

🟠 CHECK SOON

⚠️ Diagnostic Note: Symptoms can have multiple root causes. Always verify with a diagnostic scan tool before replacing parts. The fault codes listed above are possible matches for fuel economy decreased based on SAE J1939/J1587 fault code definitions and OEM service documentation.