CAT Engine 5492 Fault Code: Incorrect Throttle Lock Switch inputs
Also called Incorrect Throttle Lock Switch Inputs, Throttle Lock Switch : Erratic, Intermittent, or Incorrect
Incorrect Throttle Lock Switch inputs · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
CAT fault code 5492 fires on C15 engines when the ECM sees an invalid, erroneous, or contradictory signal from the throttle lock switch and/or the throttle lock set/accel (resume/decel) switch. The ECM logs the code and disables the throttle lock and throttle hold features until the fault clears, meaning the throttle pedal becomes the only way to control engine speed.
Medium severity. This code does not stop the engine or shut down a system, it just disables a convenience feature (throttle lock/hold). Operators lose cruise-style speed control, which can be a real annoyance and even a safety issue on machines where operators rely on locked engine speed for PTO or stationary work, so it should be diagnosed promptly rather than ignored indefinitely.
What does CAT Engine error code 5492 mean?
Fault code 5492 is set by the ECM when it receives a signal from the throttle lock switch circuit, or the throttle lock set/accel and resume/decel switch circuit, that does not make sense. This includes both switches reading open at the same time or both reading grounded at the same time, which are electrically impossible states for a normally-operating three-position switch and momentary switch pair.
The throttle lock feature lets an operator use a three-position rocker switch (AUTO, OFF, MAN) along with a two-position momentary switch to set and hold a desired engine speed, similar to a cruise control. In AUTO or MAN mode, the operator sets a speed with the throttle pedal, then locks it in. Bumping the set/accel or resume/decel switch nudges the desired speed up or down, and holding either switch ramps the speed continuously until released.
When code 5492 is active, the ECM will not trust the switch inputs, so it disables the throttle lock and throttle hold features entirely. The engine still runs and responds normally to the throttle pedal, but any automatic or manual locked-speed function is unavailable until the fault is fixed.
What triggers a CAT Engine 5492 code?
The ECM sets this code when it detects an erroneous or invalid signal from the throttle lock mode switch and/or the throttle speed set switch, including the specific condition where both the Throttle Lock Switch (Lock Off) and Throttle Lock Switch (Lock On) read open at the same time, or both read grounded at the same time. No voltage, temperature, or timing threshold is given for the fault detection itself.
Common causes of 5492
- Damaged, chafed, corroded, or pinched wiring in the harness between the ECM and the throttle lock switch
- Damaged or corroded connectors at the throttle lock switch, throttle lock mode switch, or throttle lock set/accel (resume/decel) switch
- Open circuit or short circuit in the wiring between the ECM and the switch(es)
- Faulty throttle lock switch itself (mechanical or internal electrical failure)
- Faulty throttle lock mode switch or faulty throttle speed set switch
- Faulty throttle lock resume/decel switch
- General harness problem affecting the throttle lock circuit
- Faulty ECM requiring replacement (listed as a possible cause after wiring and switches are ruled out)
How to troubleshoot CAT Engine 5492: first checks
- Inspect the wiring harness between the ECM and the throttle lock switch, throttle lock mode switch, and set/accel/resume/decel switches for abrasion, pinch points, chafing, or corrosion.
- Check all connectors in the throttle lock switch circuit for corrosion, loose pins, moisture intrusion, or damage, and clean or reseat as needed.
- Operate the throttle lock switch through all three positions (AUTO, OFF, MAN) and cycle the set/accel and resume/decel switches to check for a mechanically sticky or intermittent switch.
- Check for an open or short circuit in the wiring between the ECM and each switch using appropriate electrical test procedures.
- Verify neither the Lock Off nor Lock On switch signal is reading open on both sides, or grounded on both sides at the same time, which points to a wiring or switch fault rather than a random glitch.
- If wiring, connectors, and switches all check out, consider the ECM itself as a possible cause.
How the code clears
No separate clearing step is listed. The code is logged when the ECM detects the invalid switch condition, and the throttle lock and throttle hold features remain disabled until the underlying wiring, connector, or switch fault is repaired. Once the condition causing the erroneous signal is corrected, the ECM should stop detecting the fault on subsequent key cycles or operation.
Affected models and serial ranges
5492 appears in our records across 1 CAT Engine models. Match your machine by model and serial number.
| Model | Serial ranges |
|---|---|
| C15 | Serial range not listed in source records |
Frequently asked questions
What does CAT code 5492 mean?
It means the ECM on a C15 engine has detected an invalid or erroneous signal from the throttle lock switch, the throttle lock mode switch, or the throttle lock set/accel and resume/decel switches. The ECM responds by disabling the throttle lock and throttle hold features.
Can I still drive or operate the machine with code 5492 active?
Yes. The engine still responds to the throttle pedal normally. What you lose is the throttle lock feature, meaning you cannot set and hold a locked engine speed using the switches. The throttle pedal becomes the only way to control engine speed.
Will code 5492 damage the engine if I keep working?
No damage is indicated in the diagnostic information for this code. It disables a convenience/control feature rather than affecting core engine operation, so it is safe to keep working while you schedule a repair, but the throttle lock function will stay unavailable.
What usually causes code 5492 on a C15 engine?
The most common causes are damaged, corroded, or pinched wiring and connectors in the throttle lock switch circuit, a faulty throttle lock switch, mode switch, or set/accel/resume/decel switch, or an open or short circuit between the ECM and those switches. A faulty ECM is also a listed possible cause but should be checked last.
How do I know if it's the switch or the wiring?
Start with a visual and physical inspection of the harness and connectors for damage or corrosion, then test the wiring between the ECM and each switch for opens or shorts. If wiring checks out clean and the switches still behave erratically, the switch itself is the more likely suspect.
Is there a specific reset procedure for code 5492?
No reset procedure is listed for this code. The fix is to repair the wiring, connector, or switch causing the erroneous signal. The ECM should stop logging the fault once the underlying issue is corrected.
Does code 5492 affect any other engine functions besides throttle lock?
Based on the available information, only the throttle lock and throttle hold features are disabled. The throttle pedal continues to control engine speed as normal.