CAT Engine 413 Fault Code: 8 Volt DC Supply short to +batt
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8 Volt DC Supply short to +batt · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
CAT code 413 (SPN 678 / FMI 3) means the ECM has detected voltage above normal on the 8 volt DC sensor supply circuit, which powers the throttle position sensor. The ECM logs the code and sets the affected sensor to a default value. This can indicate a short to +Battery on the supply line, which may damage the sensor since it is not overvoltage protected.
Medium severity. The ECM protects itself from a short to battery voltage on this supply circuit, but the sensor it feeds is not protected. Running with this code active risks permanent sensor damage and puts the engine into default sensor values, which can affect performance and other readings. Diagnose before extended operation.
What does CAT Engine error code 413 mean?
The ECM supplies a regulated 5.0 volts (plus or minus 0.2 volts) to a group of pressure and identification sensors, and a separate regulated 8.0 volts (plus or minus 0.4 volts) specifically to the throttle position sensor. Code 413 concerns this 8 volt supply circuit reading above its normal range.
Supply voltage runs from the ECM to terminal 1 (or terminal A on some ECM connectors) of the sensor connector, with the return path on terminal 2 (or terminal B). The ECM has internal short circuit protection so a short to battery voltage will not damage the ECM itself, but the sensor on the other end of that wire has no such protection. If the supply line shorts to +Battery, the throttle position sensor itself may be damaged.
When this code is active, the ECM logs it and sets the throttle position sensor to a default value. That means the engine is running on a substituted, non-real value for that input until the fault is corrected, which can affect throttle response and related engine control.
What triggers a CAT Engine 413 code?
The ECM sets this code when it detects voltage above normal in the 8 volt DC sensor supply circuit that feeds the throttle position sensor. One related digital sensor supply variant sets when supply voltage is above normal for 1 second.
Common causes of 413
- Damaged or corroded connectors and/or wiring in the sensor supply circuit
- Electrical problem internal to the throttle position sensor itself
- Sensor has failed and needs to be replaced
- Intermittent connection problem in the harness or connectors
- Supply wire shorted to another wire in the harness, or shorted to engine ground
- Supply wire shorted to +Battery, which can damage the sensor since it is unprotected from overvoltage
- Problem with the ECM itself
How to troubleshoot CAT Engine 413: first checks
- Inspect the sensor connector and related wiring harness for damage, corrosion, rubbed-through insulation, or pinched wires along the supply circuit
- Check the supply wire for a short to +Battery voltage or a short to another wire in the harness, since either can trigger this code and damage the sensor
- Verify continuity and correct voltage at the sensor connector terminals (supply on terminal 1 or A, return on terminal 2 or B) with the engine running, since this code needs the engine running to become active in related variants
- Check for any other active sensor diagnostic codes, since a shorted supply may have damaged the throttle position sensor and other codes would confirm sensor damage
- Disconnect and inspect the throttle position sensor connector for moisture, corrosion, or bent pins
- If wiring and connectors check out, test or substitute the throttle position sensor to rule it out before condemning the ECM
How the code clears
No separate clearing step is listed beyond repairing the fault. Repair the sensor supply circuit (connectors, wiring, or sensor as needed), then check for any other active sensor diagnostic codes to confirm whether the sensor was damaged by the short. Once the underlying wiring, connector, or sensor problem is corrected, the code should stop being logged on the next cycle.
Affected models and serial ranges
413 appears in our records across 10 CAT Engine models. Match your machine by model and serial number.
| Model | Serial ranges |
|---|---|
| C10 | Serial range not listed in source records |
| C11 | Serial range not listed in source records |
| C12 | Serial range not listed in source records |
| C13 | Serial range not listed in source records |
| C15 | Serial range not listed in source records |
| C16 | Serial range not listed in source records |
| C175 | Serial range not listed in source records |
| C18 | Serial range not listed in source records |
| C27 | Serial range not listed in source records |
| C32 | Serial range not listed in source records |
Frequently asked questions
What does CAT code 413 mean?
It means the ECM detected the 8 volt DC sensor supply circuit, which powers the throttle position sensor, reading above its normal voltage range. The ECM logs the code and substitutes a default value for that sensor until the fault is fixed.
Is CAT fault 413 serious?
It is worth addressing promptly. The throttle position sensor is running on a default value while the code is active, and if the cause is a short to +Battery, the sensor itself can be damaged since it has no overvoltage protection.
Can a short to battery damage my ECM on code 413?
No. The ECM has internal short circuit protection on this supply, so a short to battery will not damage the ECM. However, the sensor on the other end of that wire is not protected and may be damaged.
What sensor is affected by code 413?
The 8 volt DC supply circuit affected by code 413 powers the throttle position sensor specifically, separate from the 5 volt supply that feeds the pressure sensors and other modules.
Does the engine need to be running for code 413 to set?
Related sensor supply codes on this circuit require the engine to be running before they can become active, and the ECM checks for abnormal voltage conditions during that operation.
What should I check first for code 413?
Start with the wiring and connectors on the 8 volt supply circuit to the throttle position sensor, checking for shorts to +Battery, shorts to other wires, or damage, since these are the most commonly listed causes.
Will code 413 clear itself after I fix the wiring?
No separate reset procedure is listed. Once the wiring, connector, or sensor issue is repaired, the code should stop logging on subsequent operation, but you should also check for any other active sensor codes to confirm the sensor was not damaged.