Cummins fault code 6563
Auxiliary Intermediate (PTO) Speed Switch Validation: erratic or intermittent signal
What it means
Cummins' description: Auxiliary Intermediate (PTO) Speed Switch Validation - Data erratic, intermittent or incorrect.
SPN 976 is PTO Governor State. FMI 2 means the signal is jumping around, dropping in and out, or doesn't make sense compared to other readings.
The accelerator pedal has position sensors and an idle validation switch so the ECM knows exactly what the driver is asking for. Cruise control, brake and clutch switches, PTO and vehicle speed inputs are also monitored.
What the lamp means
This code normally doesn't turn on a dash lamp. It's logged in the ECM for a technician to see, and often explains another active code.
Green, yellow, red: three ways this can look
The same code can be a quick fix or a reason to shut down. Match your situation to the closest example.
Keep an eye on it
A pedal or switch code that set once and cleared, and the pedal works normally.
Schedule a repair
Cruise doesn't work, the pedal feels dead in spots, or the code keeps returning. Have the pedal or switch checked.
Stop and get help
Engine stuck at idle or the pedal not responding, especially with a red lamp. Don't drive it in traffic. You won't have reliable throttle.
Common causes
The sensor reading itself is out of range or the condition is real, so look at the system:
- Pedal sensors disagreeing with each other
- Switch inputs that don't make sense together, like brake and throttle at once
What you can check before calling
- Check whether the engine stays at idle no matter what you do with the pedal
- Look at the pedal connector under the dash
- Check whether cruise control works
Clearing the code without fixing the cause usually brings it right back, and on emissions systems it can restart derate timers.
Engines and sources
Listed by Cummins for: QSB 6.7, QSL 9, QSX 15, QSB 4.5, QSF 3.8, QSG 12. Cummins uses the same fault code numbers across its electronic engines, including on-highway models like the ISB/B6.7, ISL/L9 and ISX/X15, though not every code applies to every engine or software level. Source: Cummins Tier 4 Fault Codes. Always confirm with Cummins service information (QuickServe) for your engine serial number.
Related Accelerator pedal and driver controls codes
- 5248 SPN 1623 FMI 13
Tachograph Output Shaft Speed: out of calibration - 5193 SPN 1632 FMI 31
Engine Torque Limit Feature: condition exists - 4526 SPN 521 FMI 2
Brake Pedal Position: erratic or intermittent signal - 4215 SPN 563 FMI 31
Anti-Lock Braking (ABS) Active: condition exists - 3845 SPN 5603 FMI 31
Cruise Control Disable Command: condition exists - 3844 SPN 5605 FMI 31
Cruise Control Pause Command: condition exists
Look up another code
Cummins fault code (like 1922), J1939 SPN and FMI (like SPN 3251 FMI 0), or an OBD-II code (like P0420).
Questions
What does Cummins fault code 6563 mean?
Cummins fault code 6563 is J1939 SPN 976 FMI 2: Auxiliary Intermediate (PTO) Speed Switch Validation - Data erratic, intermittent or incorrect. In plain terms: auxiliary intermediate (pto) speed switch validation: erratic or intermittent signal.
Can I keep driving with Cummins code 6563?
Usually, yes. This code doesn't normally turn on a lamp by itself, but check for other active codes that might be more serious. Look at the green, yellow and red examples on this page to judge your situation.
What is the SPN and FMI for Cummins code 6563?
SPN 976 identifies the part or system (PTO Governor State). FMI 2 describes the type of failure: erratic or intermittent signal.
What usually causes Cummins code 6563?
The most common causes are: pedal sensors disagreeing with each other; switch inputs that don't make sense together, like brake and throttle at once.

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