PACCAR (Kenworth & Peterbilt)
PACCAR fault code
SPN 3031 / FMI 2
PACCAR Fault Code P3899: DEF Tank Temperature – Data Erratic, Intermittent or Incorrect
P3899 on PACCAR (Kenworth & Peterbilt) engines means: DEF Tank Temperature – Data Erratic, Intermittent or Incorrect. The failure mode (FMI 2) is “data erratic, intermittent or incorrect”.
Code details
- Manufacturer
- PACCAR (Kenworth & Peterbilt)
- Applies to
- PACCAR MX-13 (2017–2020)
- Fault code
- P3899
- J1939 SPN
- 3031
- FMI
- 2 — Data erratic, intermittent or incorrect
- Truck models in source
- Kenworth T680, T880, W900, T800; Peterbilt 579, 389, 567, 367
What to do next
- Read active and inactive codes with the OEM service tool and note the occurrence count.
- FMI 2 tells the shop the type of failure to test for: data erratic, intermittent or incorrect.
- Have a heavy-duty diesel technician confirm the fault against the engine or chassis service manual before replacing parts.
Get this code diagnosed
Send one request and nearby diesel shops and mobile mechanics can quote the repair.
Owner-OperatorAdd this truck & start trial
Run your own truck?
Log maintenance, track fault codes, and get roadside breakdown dispatch.
$39.99/mo
Cancel anytime
More ways Repairius keeps vehicles running
Tools for owner-operators, shops, fleets and drivers — all in one place.
Auto & Truck Shop OS
From $99.99/mo- Work orders & job management
- Digital vehicle inspections
- Parts lookup & inventory
- Estimates, invoices & payments
Fleet Maintenance
From $129/mo- Preventive maintenance schedules
- Driver DVIRs & defect reports
- Safety & compliance clearance
- Preferred shop dispatch & approvals
My Garage
100% free- Digital glovebox for your vehicles
- Maintenance history & reminders
- Recall alerts
- Book verified local shops
Owner-Operator? Track this truck for $39.99/mo
StartFix these trucks? Get your shop listed free·Find a diesel shop
Related fault codes
- PACCAR Fault Code P3895 — DEF Tank Temperature Sensor – Short Circuit to Supply or Open Circuit
- PACCAR Fault Code P3900 — DEF Tank Temperature Sensor – Voltage Too Low or Short Circuit to Ground
- International Fault Code SPN 3031 FMI 13 — Aftertreatment 1 Diesel Exhaust Fluid Tank Temperature 1: Out Of Calibration
- International Fault Code SPN 3031 FMI 2 — Aftertreatment 1 Diesel Exhaust Fluid Tank Temperature 1: Data Erratic, Intermittent Or Incorrect
- International Fault Code SPN 3031 FMI 20 — Aftertreatment 1 Diesel Exhaust Fluid Tank Temperature 1: Data Drifted High
- International Fault Code SPN 3031 FMI 3 — Aftertreatment 1 Diesel Exhaust Fluid Tank Temperature 1: Voltage Above Normal, Or Shorted To High Source
- International Fault Code SPN 3031 FMI 4 — Aftertreatment 1 Diesel Exhaust Fluid Tank Temperature 1: Voltage Below Normal, Or Shorted To Low Source
Source: PACCAR MX-13 2017–2020 fault code list (Diesel Laptops). See also OBD-II codes.