What it means
The ignition switch run/start-position circuit has a detected electrical fault. The code does not establish the cause or resulting starting behavior.
At a glance
- Usually lights the check-engine light
How it works
The ignition switch provides the receiving module with a signal when the key or start control is in the Run or Start position. The module monitors that run/start circuit and sets P2533 when it detects an electrical fault, without specifying whether the signal is too low, too high, or interrupted.
Common causes
Most likely first.
- Worn or faulty ignition switch contacts
- Open or shorted run/start wiring
- Loose, corroded, or damaged connector
- Fault in the module receiving the switch signal
Symptoms
- Check-engine or electrical-system warning light
- Engine may not crank or may start intermittently
- Engine may stall or lose power
- Run/start accessories may behave inconsistently
How to diagnose it
- Record freeze-frame data and check whether the fault is current or intermittent, noting whether it occurs during key-on, cranking, or engine operation.
- With the key positions selected, compare the scan-tool run/start status with the actual switch position to see whether the module receives the expected state.
- Inspect the ignition switch connector and run/start wiring for loose or corroded pins, damage, or chafing.
- Check the run/start circuit for continuity and shorts, following the vehicle wiring diagram and the manufacturer's specification.
- If the wiring and switch test correctly, check the receiving module's connector, power, ground, and signal input before considering a module fault.
Common fixes
- Clean and secure a loose or corroded ignition-switch connector.
- Repair damaged or open run/start wiring and insulate any chafed sections.
- Replace a worn or faulty ignition switch after confirming its contacts fail testing.
- Repair the receiving module's connector or circuit, or replace the module only after its inputs and powers are verified.
Can I keep driving?
Intermittent cranking, stalling, or loss of run/start accessories can leave the vehicle unable to start or keep running. Avoid relying on it for a trip until the fault is diagnosed, especially if the engine has stalled.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.