Redundant Power Supply Failure (Tire Pressure Monitoring System)
This code indicates a failure in the redundant power supply for the TPMS.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The tire pressure monitoring system has lost power because its backup supply isn’t working, which could lead to false pressure readings or no readings at all.
What the computer is actually seeing
The vehicle's computer monitors the voltage levels of the tire pressure monitoring system's power supply. If it detects a voltage below a specified threshold (usually under 9 volts) for a set period (around 100 milliseconds), it triggers this code.
What a healthy reading looks like
Voltage should be between 9 to 16 volts for proper operation of the TPMS.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check the vehicle battery voltage. Ensure it's between 12.4 to 12.7 volts with the engine off. If not, charge or replace the battery.
- 22. Inspect wiring and connectors for the TPMS module. Look for frays, corrosion, or loose connections. Repair or replace as needed.
- 33. Check the TPMS fuse. If blown, replace and see if the code returns.
- 44. Test the voltage at the TPMS module connector. Confirm it's receiving at least 9 volts. If not, trace back to find where the power loss occurs.
- 55. If all checks are good and the code persists, consider replacing the TPMS module.
Common causes
- Faulty TPMS module
- Bad wiring or connectors
- Weak vehicle battery
- Corrosion at power supply connections
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
Yes, but you won't get reliable tire pressure readings, so check pressures manually until repaired.
Will this code come back after fixing?
If the underlying issue is resolved properly, the code should clear itself and not return.
Why does this code pair with other SPN codes?
These codes often indicate related power supply issues within the TPMS or electrical systems.
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