PACCAR (Kenworth & Peterbilt)
PACCAR fault code
SPN 81 / FMI 1
PACCAR Fault Code P1040: Exhaust Gas Pressure After BPV – Data Valid But Too Low
P1040 on PACCAR (Kenworth & Peterbilt) engines means: Exhaust Gas Pressure After BPV – Data Valid But Too Low. The failure mode (FMI 1) is “data valid but below normal operating range (most severe)”.
Code details
- Manufacturer
- PACCAR (Kenworth & Peterbilt)
- Applies to
- PACCAR MX-13 (2013–2016)
- Fault code
- P1040
- J1939 SPN
- 81
- FMI
- 1 — Data valid but below normal operating range (most severe)
- 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 1 tells the shop the type of failure to test for: data valid but below normal operating range (most severe).
- 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.
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Related fault codes
- PACCAR Fault Code P006B — Exhaust Gas Pressure After BPV – Data Erratic, Intermittent or Incorrect, at Ignition ON
- PACCAR Fault Code P047C — Exhaust Gas Pressure After BPV – Voltage Too Low or Short Circuit to Ground on ECU (D420) Pin (C81)
- PACCAR Fault Code P047D — Exhaust Gas Pressure After BPV – Voltage Too High or Short Circuit to Supply on ECU (D420) Pin (C81)
- PACCAR Fault Code P1039 — Exhaust Gas Pressure After BPV – Data Valid But Too High
- PACCAR Fault Code P1050 — Exhaust Gas Pressure After BPV – Data Erratic, Intermittent or Incorrect
Source: PACCAR MX-13 2013–2016 fault code list (Diesel Laptops). See also OBD-II codes.