SPN 91 — Accelerator pedal position
Do not driveTo the nearest safe stop
J1939 code SPN 91. Below — how the fault is worded at the factory by DAF, Dongfeng, Foton, Isuzu, KAMAZ, MAZ, Mercedes-Benz, Renault Trucks, SITRAK, YaMZ and ZF AS-Tronic, and what the second half of the code (FMI) means in the standard.
DAFDongfengFotonIsuzuKAMAZMAZMercedes-BenzRenault TrucksSITRAKYaMZZF AS-Tronic
DAF
| FMI 2 | Accelerator pedal F648 signal missing/implausible |
| FMI 3 | Accelerator pedal F648 voltage too high at ECU pin B35 (position sensor 1) |
| FMI 4 | Accelerator pedal F648 voltage too low at ECU pin B35 |
| FMI 19 | Accelerator pedal CAN communication error |
Dongfeng
| FMI 2 | Inconsistency between accelerator pedal signal 1 and signal 2. Scan tool code: P060D. Effect: Loss of communication with the modules, some functions are disabled. |
| FMI 3 | Short circuit to power supply of accelerator pedal signal 1 |
| FMI 4 | Short circuit to ground or open circuit of accelerator pedal signal 1 |
| FMI 9 | Timeout waiting for the pedal switch signal |
| FMI 19 | Timeout of a message from the accelerator pedal. Scan tool code: P0120. Effect: Loss of communication with the modules, some functions are disabled. |
Foton
| FMI 3 | Accelerator pedal sensor circuit voltage high |
| FMI 4 | Accelerator pedal sensor circuit voltage low |
Isuzu
| FMI 2 | Accelerator sensor 1-2 comparison fault (P1271) |
| FMI 3 | Accelerator sensor 1 fault (low voltage fault) (P1277) |
| FMI 4 | Accelerator sensor 1 fault (high voltage fault) (P1278) |
KAMAZ
| FMI 0 | Accelerator pedal (AFPS or J1939). K-line code on KamAZ-5490: ADM3 10200. |
| FMI 2 | Accelerator pedal position sensor 1 |
| FMI 3 | Accelerator pedal position sensor 1. K-line code on KamAZ-5490: ADM3 10203. |
| FMI 4 | Accelerator pedal position sensor 1. K-line code on KamAZ-5490: ADM3 10204. |
| FMI 7 | Accelerator pedal signal implausible with brake pedal pressed |
| FMI 9 | Accelerator pedal (AFPS or J1939). K-line code on KamAZ-5490: ADM3 10209. |
| FMI 19 | Accelerator pedal (AFPS or J1939). K-line code on KamAZ-5490: ADM3 10219. |
MAZ
| FMI 2 | Accelerator pedal position sensors fault - Implausible signal. Blink code: 2-2-1. Power will be reduced. Repair: Check the accelerator pedal position sensors and their wiring. |
| FMI 3 | Accelerator pedal position sensors fault - Voltage above allowed. Blink code: 2-2-1. Power will be reduced. Repair: Check the accelerator pedal position sensors and their wiring. |
| FMI 4 | Accelerator pedal position sensors fault - Voltage below allowed. Blink code: 2-2-1. Power will be reduced. Repair: Check the accelerator pedal position sensors and their wiring. |
| FMI 7 | Fault flagged by the accelerator/brake pedal plausibility check - Accelerator pedal signal implausible. Blink code: 2-2-5. Repair: Check the accelerator and brake pedal position sensors and their wiring. |
Mercedes-Benz
| FMI 0 | Accelerator Pedal Circuit shorted to Ubat |
| FMI 2 | Accelerator Pedal out of adjustment (Learn error) |
| FMI 4 | Accelerator Pedal Circuit shorted to GND |
| FMI 7 | 2-Channel Accelerator Pedal Idle Not Recognized (idle area not evaluated) |
| FMI 8 | 2-Channel Accelerator Pedal Signal 1 Missing |
| FMI 10 | Throttle pedal rationality check failed |
| FMI 13 | J1939 EEC2 message is missing or not available |
Renault Trucks
| FMI 3 | Accelerator pedal — supply or signal shorted to positive. Repair: Check the continuity and insulation of the wiring (SL2/3, SL2/4), check the supply voltage (4.5-5.25 V). Check the continuity and insulation of the wiring with respect to +24 V (SL2/4), press the pedal and check the potentiometer signal (0.25-4.6 V). |
| FMI 4 | EBS CAN fault. Repair: Run the diagnostic check of the EBS unit. Check the programming. Check the CAN bus communication (X1A/8, X1A/12, X1A/13, X1A/14). Switch the ignition off, switch it on again and repeat the test. If the fault persists, replace the control unit. |
SITRAK
| FMI 0 | Accelerator pedal channel 1 signal above idle switch signal limit |
| FMI 1 | Accelerator pedal channel 1 signal below idle switch signal limit |
| FMI 2 | Accelerator pedal CAN signal not plausible. Scan tool code: P060D. Effect: Loss of communication with the modules, some functions are disabled. |
| FMI 3 | High voltage on accelerator pedal channel 1 signal |
| FMI 4 | Low voltage on accelerator pedal channel 1 signal |
| FMI 14 | Accelerator pedal CAN signal quality error. Scan tool code: P0120. Effect: Loss of communication with the modules, some functions are disabled. |
| FMI 16 | Accelerator pedal channel 1 signal opening greater than channel 2 signal |
| FMI 18 | Accelerator pedal channel 1 signal opening less than channel 2 signal |
| FMI 19 | Accelerator pedal CAN signal error. Scan tool code: P0120. Effect: Loss of communication with the modules, some functions are disabled. |
| FMI 22 | Kickdown error, the DIO switch is faulty. Scan tool code: P0120. |
| FMI 31 | Tracking voltage error between accelerator pedal channel 1 and channel 2 signals |
YaMZ
| FMI 2 | Accelerator pedal position sensor fault (Implausible signal). Blink code: 2-2-1. Power will be reduced. Repair: Check the accelerator pedal position sensors and their wiring. |
| FMI 3 | Accelerator pedal position sensor fault (Voltage above allowable limit). Blink code: 2-2-1. Power will be reduced. Repair: Check the accelerator pedal position sensors and their wiring. |
| FMI 4 | Accelerator pedal position sensor fault (Voltage below allowable limit). Blink code: 2-2-1. Power will be reduced. Repair: Check the accelerator pedal position sensors and their wiring. |
| FMI 7 | Fault detected by accelerator/brake pedal plausibility check (Accelerator pedal signal implausible). Blink code: 2-2-5. Repair: Check the accelerator and brake pedal position sensors and their wiring. |
ZF AS-Tronic
ZF AS-Tronic uses its own fault numbering: the number in the table below is an internal ZF code, not a J1939 SPN. It matches the title of this page by digit only and means something different.
| FMI 4 | CAN bus request timeout: EBC1 (brake request message). |
What FMI means in J1939
| SPN 91 FMI 091/0 · 91.0 | data above normal range (most severe level) |
| SPN 91 FMI 191/1 · 91.1 | data below normal range (most severe level) |
| SPN 91 FMI 291/2 · 91.2 | data erratic or intermittent |
| SPN 91 FMI 391/3 · 91.3 | voltage above normal or shorted high |
| SPN 91 FMI 491/4 · 91.4 | voltage below normal or shorted to ground |
| SPN 91 FMI 791/7 · 91.7 | mechanical system not responding |
| SPN 91 FMI 891/8 · 91.8 | abnormal frequency or pulse width |
| SPN 91 FMI 991/9 · 91.9 | abnormal update rate |
| SPN 91 FMI 1091/10 · 91.10 | abnormal rate of change |
| SPN 91 FMI 1391/13 · 91.13 | calibration out of range |
| SPN 91 FMI 1491/14 · 91.14 | manufacturer-specific instructions |
| SPN 91 FMI 1691/16 · 91.16 | above normal — moderate severity |
| SPN 91 FMI 1891/18 · 91.18 | below normal — moderate severity |
| SPN 91 FMI 1991/19 · 91.19 | error in received network data |
| SPN 91 FMI 3191/31 · 91.31 | condition exists (see manufacturer description) |
Can I keep driving
Do not drive. Stop as soon as it’s safe to do so — don’t keep going.
What happens if you keep driving
Time you have: To the nearest safe stopThe code is flagged critical: the manufacturer considers it unsafe to keep driving without checking.
This code alone cannot say what will fail next, so stop at the first safe opportunity and look at it on the spot.
That said, the manufacturer flags this code as critical — if in doubt, it is safer to stop and check on the spot.
Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.