MODE 01 · PID 04

Calculated engine load

Calculated load is an ECU calculation, not throttle position. Its meaning depends on engine type and operating state.

Formula
A × 100 / 255
Data bytes
1
Units
%

A worked decoding example

Request: 01 04

Response: 41 04 80

Data: 80 → 50.196078 %

The example shows service, PID and data only. It omits adapter headers, CAN identifier, length and padding. It is not a live vehicle reading.

Reading context

Compare at a similar engine speed, temperature and accessory load. A percentage alone does not identify a restricted intake.

A decoded value is a measurement, not a diagnosis. Encoding limits are not normal operating limits. Confirm vehicle support and the manufacturer’s procedure.

Byte decoder

Your input stays in this browser.MODE 01

FormulaA × 100 / 255 → %

A decoded value is a measurement, not a diagnosis. Encoding limits are not normal operating limits. Confirm vehicle support and the manufacturer’s procedure.

Sources

  1. python-OBD: Mode 01 command table ↗
  2. python-OBD: byte decoding implementation ↗
  3. CSS Electronics: OBD-II PID and response frames ↗
  4. California BAR: OBD test reference ↗

Independent reference; no affiliation with SAE, vehicle manufacturers or regulators. Sources checked 28 October 2026.