Audi P31C500
110 up to 48 Months/50,000 Miles. G10 for CPO Covered Vehicles – Verify Owner. If the vehicle is outside any warranty, this Technical Service Bulletin is informational only
Quick answer
For certain US-market 2021–2022 Audi e-tron vehicles, Audi technical-service evidence links DTC P31C500 to a diagnostic procedure for coolant valves and verification of high-voltage battery charging after repair. If valve values do not change during the specified output diagnostic test, Audi directs replacement of the corresponding coolant valve and cooling-system bleeding per the Elsa Repair Manual.
This page separates verified manufacturer/regulator evidence from supporting material. Unsupported causes, repairs or safety conclusions are not guessed.
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1. What does P31C500 mean?
For certain US-market 2021–2022 Audi e-tron vehicles, Audi technical-service evidence links DTC P31C500 to a diagnostic procedure for coolant valves and verification of high-voltage battery charging after repair. If valve values do not change during the specified output diagnostic test, Audi directs replacement of the corresponding coolant valve and cooling-system bleeding per the Elsa Repair Manual.
2. Technical explanation
The supplied official Audi/NHTSA service-bulletin evidence instructs technicians to perform an output diagnostic test for the valves. If the values do not change during that test, the corresponding valve is to be replaced according to Elsa Repair Manual instructions, including bleeding the cooling system. After the repair, the high-voltage battery must be rechecked to confirm it charges at a normal rate and that P31C500 does not reset. The precise manufacturer definition of P31C500 is not established by the supplied verified evidence.
3. What system is affected?
Cooling-system coolant valves; the bulletin also requires a post-repair check of high-voltage battery charging performance.
4. How serious is this code?
Not yet established by verified evidence.
5. Symptoms you may notice
- P31C500 may be set again after repair if the repair does not resolve the condition.
- The service procedure calls for confirmation that the high-voltage battery charges at a normal rate after repair.
6. Possible causes
- A coolant-valve value that does not change during Audi's specified output diagnostic test is the verified test condition for replacement of the corresponding valve.
- No further root causes are established by the supplied verified evidence.
7. Can I still drive the vehicle?
Not yet established by verified evidence.
8. Can I charge the vehicle?
Not yet established by verified evidence. The bulletin requires verification that the high-voltage battery charges at a normal rate after the repair.
9. What you can safely do
- Arrange diagnosis by an Audi-qualified service facility.
- Provide the technician with DTC P31C500 and the applicable Audi service-bulletin information.
- Do not attempt coolant-valve replacement, cooling-system bleeding, or high-voltage battery service without appropriate manufacturer procedures and qualified training.
10. Step-by-step troubleshooting
- A technician performs the specified output diagnostic test for the valves.
- If values do not change during the test, the corresponding coolant valve is replaced according to the Elsa Repair Manual.
- The cooling system is bled according to the Elsa Repair Manual.
- After repair, the technician rechecks high-voltage battery charging rate and confirms P31C500 has not reset.
11. When to contact service
Contact an Audi-qualified service facility for diagnosis and repair. The supplied bulletin identifies coolant-valve testing, possible valve replacement, cooling-system bleeding, and post-repair charging verification.
12. What the service center may check
- Perform the output diagnostic test for the valves.
- Determine whether valve values change during output diagnostic test mode.
- After repair, verify that the high-voltage battery charges at a normal rate.
- Confirm that DTC P31C500 has not been set again.
13. Possible repair or resolution
- If the values do not change during the output diagnostic test, replace the corresponding coolant valve according to Elsa Repair Manual instructions.
- Bleed the cooling system according to Elsa Repair Manual instructions.
- Recheck high-voltage battery charging and verify P31C500 does not return.
14. Affected vehicles
- Audi e-tron · 2021–2022 · US
- Audi e-tron · 2021 · US
15. Related TSBs / service bulletins
- Audi/NHTSA Manufacturer Communication 10202582, document A1921242064025_3, published October 19, 2021. It describes coolant-valve output testing, replacement when values do not change, cooling-system bleeding, and post-repair high-voltage battery charging verification.
- Audi/NHTSA Manufacturer Communication 10201539, document A1921232064025_2, published September 22, 2021. It provides the same verified service direction.
- The bulletin lists Service Number 1985 and Damage Code 0040. It references labor operation “Replace coolant valve 9384 19XX”; associated-operation times are to be obtained from SRT.
- The bulletin states warranty claim type 110 up to 48 months/50,000 miles and G10 for CPO-covered vehicles, with owner verification. Outside applicable warranty, it states the bulletin is informational only.
16. Recall information
- Not yet established by verified evidence.
17. Official manufacturer information
Verified source: NHTSA-hosted Audi manufacturer communication PDFs 10202582 and 10201539. Applicability supplied with this record is US-market Audi e-tron model years 2021–2022. Source: https://static.nhtsa.gov/odi/tsbs/2021/MC-10202582-0001.pdf
19. Frequently asked questions
What does the verified Audi procedure require for P31C500?
It requires an output diagnostic test for the valves. If values do not change during the test, Audi directs replacement of the corresponding valve, cooling-system bleeding per Elsa Repair Manual instructions, and post-repair verification of normal high-voltage battery charging and no repeat P31C500.
Does the evidence confirm that P31C500 means a failed coolant valve?
No. The supplied evidence identifies a test condition: if a valve's values do not change during the output diagnostic test, replace that corresponding valve. It does not establish that every P31C500 is caused by a failed valve.
Which vehicles are covered by the supplied applicability data?
US-market Audi e-tron vehicles for model years 2021–2022. One supplied applicability entry lists 2021 only; another lists 2021–2022.