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SPN 974 — Remote Accelerator Pedal Position

Safe to driveDrivable, but watch it yourself

Updated: 2026-11-10

J1939 code SPN 974. Below — how the fault is worded at the factory by Cummins ISB, DAF, Dongfeng, KAMAZ-5490, MAZ, Mercedes-Benz and YaMZ, and what the second half of the code (FMI) means in the standard.

How to check it yourself

Remote accelerator or hand throttle — a second control for engine speed: on work equipment, in the body, at the power take-off.

What it should read

Reference voltage at the connector, ignition on5.0 V ± 0.25
Signal in the working range0.5…4.5 V

Check order

  1. Find out where the remote throttle is on this vehicle: the PTO controller, buttons on the steering wheel, the body builder's remote panel.
  2. Check the connector on the panel — it is often outside the cab, in the dirt.
  3. If there is no remote throttle on the vehicle but the code is present — the parameter has been switched on by mistake: switch it off in the ECU.
  4. Supply and signal at the connector — as for the accelerator pedal.

Common causes — from most to least frequent

  1. Connector of the remote panel outside the cab.
  2. Parameter enabled, with no panel fitted.
  3. The panel itself.

Cummins ISBDAFDongfengKAMAZ-5490MAZMercedes-BenzYaMZ

Cummins ISB 6.7 engine

FMI 3Remote accelerator pedal position sensor 1 circuit voltage high
FMI 4Remote accelerator pedal position sensor 1 circuit voltage low
FMI 19J1939 multiplexing remote accelerator pedal system network data error

DAF

FMI 3Remote throttle control C911 short to power supply at pin B21/B26/B32
FMI 4Remote throttle control C911 short to ground at pin B21/B26/B32
FMI 19Remote throttle control C911 CAN communication error

Dongfeng

FMI 3Short circuit to power supply of the remote accelerator pedal signal
FMI 4Short circuit to ground of the remote accelerator pedal signal
FMI 19Timeout of a message from the remote accelerator pedal

KAMAZ-5490 (Mercedes, K-line)

FMI is per the block maker's own table, not the J1939 table below.

FMI 2Remote accelerator (HFG): supply voltage out of range at HFG+. K-line code on KamAZ-5490: ADM3 14202.
FMI 3Remote accelerator (HFG): voltage too high. K-line code on KamAZ-5490: ADM3 14203.
FMI 4Remote accelerator (HFG): voltage too low. K-line code on KamAZ-5490: ADM3 14204.

MAZ

FMI 2Manual damper fault - Implausible signal. Blink code: 2-1-8. Power will be reduced. Repair: Check the flap wiring.
FMI 3Manual damper fault - Voltage above allowed. Blink code: 2-1-8. Power will be reduced. Repair: Check the flap wiring.
FMI 4Manual damper fault - Voltage below allowed. Blink code: 2-1-8. Power will be reduced. Repair: Check the flap wiring.

Mercedes-Benz

FMI 3Remote Accelerator Pedal Circuit shorted to Ubat
FMI 4Remote Accelerator Pedal Circuit shorted to GND

YaMZ

FMI 2Manual throttle fault (Implausible signal). Blink code: 2-1-8. Power will be reduced. Repair: Check the flap wiring.
FMI 3Manual throttle fault (Voltage above allowable limit). Blink code: 2-1-8. Power will be reduced. Repair: Check the flap wiring.
FMI 4Manual throttle fault (Voltage below allowable limit). Blink code: 2-1-8. Power will be reduced. Repair: Check the flap wiring.

What FMI means in J1939

SPN 974 FMI 2974/2 · 974.2data erratic or intermittent
SPN 974 FMI 3974/3 · 974.3voltage above normal or shorted high
SPN 974 FMI 4974/4 · 974.4voltage below normal or shorted to ground
SPN 974 FMI 19974/19 · 974.19error in received network data

Can I keep driving

Safe to drive. Below — how much time you have and what happens if you keep going.

What happens if you keep driving

Time you have: Drivable, but watch it yourself

This is an electrical fault: an open, a short or a bad contact in the sensor circuit. The value it measures is most likely fine.

You can drive. But until the circuit is repaired this system runs blind and cannot warn you about a real failure.

Nearby: other

Related codes

Makes with this code

MAZYaMZDongfengDAFMercedes-BenzCummins ISBKAMAZ-5490

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