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Hyundai C1687

MDPS ECU (or Power Pack Assy). If DTC returns and MDPS operation is normal, continue investigation into wiring issues. For TMa, if C1688 occurs along wit h C1700, replace Power Pac

DriveNot yet established by verified evidence. The verified bulletin distinguishes a condition in which MDPS is inoperable, but it does not provide a drive/no-drive determination.
ChargeNot yet established by verified evidence. The supplied evidence does not identify C1687 as a charging-system diagnostic code.
ServiceContact a Hyundai dealer or qualified Hyundai service provider for MDPS/C-MDPS diagnosis, particularly if the code returns or MDPS is inoperable.
Confidence95%

Quick answer

Hyundai DTC C1687 is identified in verified Hyundai service-bulletin evidence as “CAN time out VSM” in the MDPS/C-MDPS context. The evidence directs diagnosis of the C-MDPS power connector and fuse, ground line, ECU/VSM CAN line, and GDS communication status. If the DTC returns and MDPS is inoperable, the bulletin directs replacement of the C-MDPS ECU or Power Pack assembly; if MDPS operates normally, it directs continued wiring investigation.

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 C1687 mean?

Hyundai DTC C1687 is identified in verified Hyundai service-bulletin evidence as “CAN time out VSM” in the MDPS/C-MDPS context. The evidence directs diagnosis of the C-MDPS power connector and fuse, ground line, ECU/VSM CAN line, and GDS communication status. If the DTC returns and MDPS is inoperable, the bulletin directs replacement of the C-MDPS ECU or Power Pack assembly; if MDPS operates normally, it directs continued wiring investigation.

2. Technical explanation

Verified Hyundai bulletin evidence labels C1687 as “CAN time out VSM.” MDPS refers to the motor-driven power steering system, and the cited procedure places this code in a C-MDPS diagnostic path. The documented checks are the C-MDPS power connector and fuse, C-MDPS ground line, C-MDPS ECU/VSM CAN line, and communication status with GDS. The bulletin also states to check for C1259; if C1259 is present with these DTCs, replace the column and housing assembly. The provided evidence does not establish an EV high-voltage battery, charging, or propulsion-system fault for C1687.

3. What system is affected?

MDPS/C-MDPS motor-driven power steering and ECU/VSM CAN communication.

4. How serious is this code?

Not yet established by verified evidence.

5. Symptoms you may notice

  • A warning lamp illuminated with DTC(s) present is described in Hyundai TSB 22-ST-001H for the R-MDPS diagnostic flowchart.
  • MDPS may be inoperable if C1687 returns; this condition is specifically addressed in Hyundai TSBs 20-ST-001H-1 and 20-ST-001H-2.
  • Other symptoms are not yet established by verified evidence.

6. Possible causes

  • A CAN timeout involving VSM, as identified by the C1687 description in Hyundai TSBs 20-ST-001H-1 and 20-ST-001H-2.
  • C-MDPS power-connector or fuse condition requiring inspection.
  • C-MDPS ground-line condition requiring inspection.
  • C-MDPS ECU/VSM CAN-line condition requiring inspection.
  • Communication-status issue requiring assessment with GDS.
  • If MDPS remains normal when the DTC returns, Hyundai directs continued investigation into wiring issues.

7. Can I still drive the vehicle?

Not yet established by verified evidence. The verified bulletin distinguishes a condition in which MDPS is inoperable, but it does not provide a drive/no-drive determination.

8. Can I charge the vehicle?

Not yet established by verified evidence. The supplied evidence does not identify C1687 as a charging-system diagnostic code.

9. What you can safely do

  • Do not attempt high-voltage repairs; no high-voltage repair procedure is established by the supplied evidence.
  • Have a qualified Hyundai service provider diagnose the MDPS/C-MDPS system using the documented bulletin procedure.
  • Record whether the MDPS is operating normally or is inoperable when C1687 returns.
  • Provide all stored DTCs to the service provider, including whether C1259, C1688, or C1700 are present.

10. Step-by-step troubleshooting

  1. Check the C-MDPS power connector and fuse.
  2. Check the C-MDPS ground line.
  3. Check the C-MDPS ECU/VSM CAN line.
  4. Check communication status with GDS.
  5. Check for C1259. The bulletin states that if C1259 is present with these DTCs, replace the column and housing assembly.
  6. If C1687 returns and MDPS is inoperable, Hyundai directs replacement of the C-MDPS ECU or Power Pack assembly.
  7. If C1687 returns and MDPS operation is normal, Hyundai directs continued investigation into wiring issues.

11. When to contact service

Contact a Hyundai dealer or qualified Hyundai service provider for MDPS/C-MDPS diagnosis, particularly if the code returns or MDPS is inoperable.

12. What the service center may check

  • Inspect C-MDPS power connector and fuse.
  • Inspect C-MDPS ground line.
  • Inspect C-MDPS ECU/VSM CAN line.
  • Assess GDS communication status.
  • Check for C1259 with the relevant DTCs.
  • For the R-MDPS flowchart in TSB 22-ST-001H, check R-MDPS connectors and wiring, erase DTC(s), and re-check.

13. Possible repair or resolution

  • If C1687 returns and MDPS is inoperable, Hyundai TSBs 20-ST-001H-1 and 20-ST-001H-2 direct replacement of the C-MDPS ECU or Power Pack assembly.
  • If C1687 returns and MDPS operation is normal, Hyundai directs continued investigation into wiring issues.
  • If C1259 is present with the applicable DTCs, Hyundai directs replacement of the column and housing assembly.
  • TSB 22-ST-001H lists C1687 in a power-pack-related R-MDPS DTC group and directs Power Pack assembly replacement after its stated connector/wiring check, DTC erasure, and re-check process.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Hyundai TSB 22-ST-001H, published January 6, 2022: R-MDPS diagnostic repair flowchart. It lists C1687 as power-pack-related and describes checking R-MDPS connectors and wiring, erasing DTCs, re-checking, and replacing the Power Pack assembly in the documented flow.
  • Hyundai TSB 20-ST-001H-2, published September 9, 2020: identifies C1687 as “CAN time out VSM” and provides C-MDPS diagnostic and replacement guidance.
  • Hyundai TSB 20-ST-001H-1, published August 10, 2020: identifies C1687 as “CAN time out VSM” and provides the same cited C-MDPS diagnostic and replacement guidance.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Verified official NHTSA-hosted Hyundai manufacturer communications: 22-ST-001H (https://static.nhtsa.gov/odi/tsbs/2022/MC-10207815-0001.pdf); 20-ST-001H-2 (https://static.nhtsa.gov/odi/tsbs/2020/MC-10180981-0001.pdf); 20-ST-001H-1 (https://static.nhtsa.gov/odi/tsbs/2020/MC-10179244-0001.pdf).

19. Frequently asked questions

What does Hyundai C1687 mean?

Verified Hyundai bulletin evidence identifies C1687 as “CAN time out VSM” in the C-MDPS/MDPS diagnostic context.

What does Hyundai direct technicians to inspect for C1687?

The documented checks are the C-MDPS power connector and fuse, ground line, ECU/VSM CAN line, and communication status with GDS.

What if C1687 returns and power steering is inoperable?

Hyundai TSBs 20-ST-001H-1 and 20-ST-001H-2 direct replacement of the C-MDPS ECU or Power Pack assembly.

What if C1687 returns but MDPS operates normally?

Hyundai directs continued investigation into wiring issues.

Does C1687 establish a charging or high-voltage battery problem?

No such connection is established by the supplied verified evidence.

20. Sources & verification

Verified
Hyundai C1687: MDPS ECU (or Power Pack Assy). If DTC returns and MDPS… | EV Diagnostics