Do not driveTo the nearest safe stop
J1939 code SPN 27. Below — how the fault is worded at the factory by MAZ, Renault Trucks, SITRAK, YaMZ and ZF AS-Tronic, and what the second half of the code (FMI) means in the standard.
MAZRenault TrucksSITRAKYaMZZF AS-Tronic
| FMI 2 | EGR valve pneumatic actuator stuck - Bypass valve stuck. Blink code: 6-6-3. Repair: Check the pneumatic actuator, the bypass flap and the EGR flap position sensor. |
| FMI 3 | EGR valve position error - Control signal above allowed. Blink code: 6-6-1. Repair: Check the EGR flap and its wiring. |
| FMI 4 | EGR valve position error - Control signal below allowed. Blink code: 6-6-1. Repair: Check the EGR flap and its wiring. |
| FMI 12 | EGR valve pneumatic actuator stuck - General error. Blink code: 6-6-3. Repair: Check the pneumatic actuator, the bypass flap and the EGR flap position sensor. |
| FMI 20 | EGR valve pneumatic actuator stuck - Trim coefficient drifted far from its initial value. Blink code: 6-6-3. Repair: Check the pneumatic actuator, the bypass flap and the EGR flap position sensor. |
| FMI 21 | EGR valve pneumatic actuator stuck - Trim coefficient changed sharply within a drive cycle. Blink code: 6-6-3. Repair: Check the pneumatic actuator, the bypass flap and the EGR flap position sensor. |
| FMI 8 | Engine CAN bus fault. Repair: Run the diagnostic check of the EECU electronic unit. Check the parameters. Switch the ignition off, switch it on again and repeat the test. If the fault persists, replace the control unit. |
| FMI 0 | EGR valve jammed open. Scan tool code: P0402. Effect: Torque may be limited. |
| FMI 1 | EGR valve jammed closed. Scan tool code: P0401. Effect: Torque may be limited. |
| FMI 2 | EGR valve mechanical stop learning value drifted out of range. Scan tool code: P0404. Effect: Torque may be limited. |
| FMI 3 | EGR valve actuator circuit short to battery. Scan tool code: P0403. Effect: Torque may be limited. |
| FMI 4 | EGR valve actuator circuit short to ground. Scan tool code: P0403. Effect: Torque may be limited. |
| FMI 8 | Long-term drift of the EGR valve closed-position learning value. Scan tool code: P0404. Effect: Torque may be limited. |
| FMI 9 | Long-term drift of the EGR valve open-position learning value. Scan tool code: P0404. Effect: Torque may be limited. |
| FMI 10 | EGR valve frozen: persistent governor deviation at cold start. Scan tool code: P0404. Effect: DPF regeneration is disrupted, engine speed limited. |
| FMI 11 | Intermittent fault in the EGR valve actuator circuit (poor contact). Scan tool code: P0409. Effect: Torque may be limited. |
| FMI 12 | EGR valve governor deviation at cold start. Scan tool code: P0404. Effect: DPF regeneration is disrupted, engine speed limited. |
| FMI 13 | EGR valve position sensor voltage above the upper limit. Scan tool code: P0406. Effect: Torque may be limited. |
| FMI 14 | EGR valve position sensor voltage below the lower limit. Scan tool code: P0405. Effect: Torque may be limited. |
| FMI 15 | EGR valve fully-open learning value beyond the mechanical stop. Scan tool code: P0404. Effect: Torque may be limited. |
| FMI 16 | EGR valve governor deviation below the lower limit (large negative). Scan tool code: P0402. Effect: Torque may be limited. |
| FMI 17 | EGR valve closed-position learning value beyond the limit. Scan tool code: P0404. Effect: Torque may be limited. |
| FMI 18 | EGR valve governor deviation above the upper limit (large positive). Scan tool code: P0401. Effect: Torque may be limited. |
| FMI 19 | EGR valve position feedback failure. Scan tool code: P0403. Effect: Torque limited, the engine may shut down. |
| FMI 20 | EGR valve position physical value above the upper limit. Scan tool code: P0409. Effect: Torque may be limited. |
| FMI 21 | EGR valve position physical value below the lower limit. Scan tool code: P0409. |
| FMI 22 | Short-term drift of the EGR valve closed-position learning value. Scan tool code: P0404. |
| FMI 23 | Short-term drift of the EGR valve open-position learning value. Scan tool code: P0404. |
| FMI 24 | Over-temperature of the EGR valve powerstage in the ECU. Scan tool code: P0403. Effect: Torque limited, the engine may shut down. |
| FMI 2 | EGR valve pneumatic actuator seized (Bypass valve seized). Blink code: 6-6-3. Repair: Check the pneumatic actuator, the bypass flap and the EGR flap position sensor. |
| FMI 3 | EGR valve position fault (Control signal above allowable limit). Blink code: 6-6-1. Repair: Check the EGR flap and its wiring. |
| FMI 4 | EGR valve position fault (Control signal below allowable limit). Blink code: 6-6-1. Repair: Check the EGR flap and its wiring. |
| FMI 12 | EGR valve pneumatic actuator seized (General fault). Blink code: 6-6-3. Repair: Check the pneumatic actuator, the bypass flap and the EGR flap position sensor. |
| FMI 20 | EGR valve pneumatic actuator seized (Adaptation coefficient deviated significantly from initial value). Blink code: 6-6-3. Repair: Check the pneumatic actuator, the bypass flap and the EGR flap position sensor. |
| FMI 21 | EGR valve pneumatic actuator seized (Adaptation coefficient deviated significantly over the drive cycle). Blink code: 6-6-3. Repair: Check the pneumatic actuator, the bypass flap and the EGR flap position sensor. |
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 8 | No CAN bus signal: "engine brake configuration" (engine configuration message). |
Do not drive. Stop as soon as it’s safe to do so — don’t keep going.
The 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.