Kia C1259
MDPS MOTOR, ECU AND/OR STEERING COLUMN HOUSING Pa
Quick answer
For the listed US Kia Niro, Optima, and Soul model years 2015–2020, C1259 is identified as “MDPS MOTOR, ECU AND/OR STEERING COLUMN HOUSING Pa.” Verified Kia service-bulletin evidence directs replacement of the steering column and housing assembly when C1259 is present in the specified diagnostic path; if the DTC returns, replace the MDPS ECU.
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 C1259 mean?
For the listed US Kia Niro, Optima, and Soul model years 2015–2020, C1259 is identified as “MDPS MOTOR, ECU AND/OR STEERING COLUMN HOUSING Pa.” Verified Kia service-bulletin evidence directs replacement of the steering column and housing assembly when C1259 is present in the specified diagnostic path; if the DTC returns, replace the MDPS ECU.
2. Technical explanation
MDPS refers to the motor-driven power steering system. The supplied official Kia bulletin evidence associates C1259 with the MDPS motor, ECU and/or steering-column housing diagnostic area. In the bulletin’s diagnostic procedure for C1623 CAN Time Out SAS, technicians are directed to check the MDPS power connector and fuse, ground line, ECU/VSM CAN line, and communication status with GDS. The procedure then states that, if C1259 is present, the column and housing assembly should be replaced; if the DTC returns, the MDPS ECU should be replaced. The evidence does not establish a complete standalone fault definition beyond the supplied code title.
3. What system is affected?
Motor Driven Power Steering (MDPS), including the steering-column housing assembly and MDPS ECU.
4. How serious is this code?
Not yet established by verified evidence.
5. Symptoms you may notice
Not yet established by verified evidence.
6. Possible causes
- The verified bulletin identifies the MDPS motor, ECU and/or steering-column housing area in the C1259 title.
- Within the bulletin’s C1623 diagnostic path, C1259 being present leads to replacement of the steering column and housing assembly. The evidence does not establish a more specific root cause for C1259 alone.
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.
9. What you can safely do
- Arrange diagnosis by a qualified Kia service provider or similarly qualified technician.
- Provide the stored DTC and the official Kia bulletin references TSB CHA084 Rev. 3 or Rev. 4 to the service facility.
- Do not attempt steering-column, MDPS ECU, or motor replacement based solely on this page.
10. Step-by-step troubleshooting
- Verified TSB CHA084 diagnostic steps, when following the C1623 CAN Time Out SAS path, are: check the MDPS power connector and fuse; check the MDPS ground line; check the MDPS ECU/VSM CAN line; and check communication status with GDS.
- In that same path, check for DTC C1259. If it is present, the bulletin directs replacement of the column and housing assembly. If the DTC returns, it directs replacement of the MDPS ECU.
- The supplied evidence does not establish a separate do-it-yourself test procedure for C1259.
11. When to contact service
Service is appropriate because the verified Kia bulletin specifies component replacement steps for C1259 within its MDPS diagnostic procedure. Whether service is immediately required is not yet established by verified evidence.
12. What the service center may check
- Check MDPS power connector and fuse, as specified in the C1623 diagnostic path of TSB CHA084.
- Check the MDPS ground line.
- Check the MDPS ECU/VSM CAN line.
- Check communication status with GDS.
- Check whether C1259 is present during the specified diagnostic path.
13. Possible repair or resolution
- Per TSB CHA084, when C1259 is present in the bulletin’s C1623 diagnostic path, replace the steering column and housing assembly.
- If the DTC returns after that replacement, replace the MDPS ECU.
- No further repair outcome is established by the supplied verified evidence.
14. Affected vehicles
- Kia Niro · 2015–2020 · US
- Kia Optima · 2015–2020 · US
- Kia Soul · 2015–2020 · US
15. Related TSBs / service bulletins
- Kia TSB CHA084 Rev. 4, “Multiple Models,” November 2018. NHTSA manufacturer communication MC-10168850-0001: https://static.nhtsa.gov/odi/tsbs/2019/MC-10168850-0001.pdf
- Kia TSB CHA084 Rev. 3. NHTSA manufacturer communication MC-10167301-0001: https://static.nhtsa.gov/odi/tsbs/2019/MC-10167301-0001.pdf
16. Recall information
No recall relationship is established by verified evidence.
17. Official manufacturer information
Verified official evidence consists of Kia manufacturer communications published through NHTSA: TSB CHA084 Rev. 3 and Rev. 4. The supplied applicability data identifies US-market 2015–2020 Kia Niro, Optima, and Soul vehicles. Exact vehicle applicability should be confirmed by a service provider using the vehicle identification number and current Kia service information.
19. Frequently asked questions
What does Kia code C1259 mean?
The supplied verified diagnostic record labels C1259 as “MDPS MOTOR, ECU AND/OR STEERING COLUMN HOUSING Pa.” The evidence does not establish a fuller standalone definition.
What repair does the Kia bulletin specify when C1259 is present?
In the TSB CHA084 C1623 diagnostic path, Kia directs replacement of the steering column and housing assembly when C1259 is present. If the DTC returns, the bulletin directs replacement of the MDPS ECU.
Which vehicles are covered by the supplied applicability data?
The supplied data lists US-market 2015–2020 Kia Niro, Optima, and Soul vehicles.
Is it safe to drive with C1259?
Not yet established by verified evidence.
Does C1259 affect EV charging?
Not yet established by verified evidence.