Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC P16C3 (31): DC-DC Converter Temperature Sensor Circuit Malfunction
- Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
- If the IPU module fan duct is blocked, DTC P16C3 (31) may be detected.
- If the DTC cannot be cleared, do the troubleshooting for DTC U1204 (55).
- Turn the ignition switch to ON (II).
- Clear the DTC with the HDS (see DTC CLEAR ).
- Check for Pending or Confirmed DTCs with the HDS.
Is DTC U1448 (63), U1220 (34), or U1221 (35) indicated?
YES -Go to the indicated DTC's troubleshooting.
NO -go to step 4.
- Check the DC-DC CONVERTER TEMPERATURE in the DATA LIST with the HDS.
Is more than 259 °F (126 °C), or less than -42 °F (-41 °C) indicated?
YES -go to step 5.
NO -Intermittent failure, the system is OK at this time. Check the IPU module air duct and the IPU module fan for disconnection, damage, or obstructions.
- Turn the ignition switch to LOCK (0).
- Check the IPU module air duct and the IPU module fan for disconnection, damage, or obstructions.
Are the IPU module air duct and the IPU module fan OK?
YES -Replace the DC-DC converter (see DC-DC CONVERTER REMOVAL/INSTALLATION ), then go to step 7.
NO -Repair the IPU module air duct or the IPU module fan as needed, then go to step 7.
- Turn the ignition switch to ON (II).
- Clear the DTC with the HDS (see DTC CLEAR ).
- Check for Pending or Confirmed DTCs with the HDS.
Is DTC P16C3 (31) indicated?
YES -Check for poor connections or loose terminals at the DC-DC converter and the MCM, then go to step 1.
NO -go to step 10.
- Monitor the OBD STATUS for DTC P16C3 (31) in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 9, go to the indicated DTC's troubleshooting.
NO -If the screen indicates FAILED, check for poor connections or loose terminals at the DC-DC converter and the MCM, then go to step 1. If the screen indicates NOT COMPLETED, keep the ignition switch ON (II) until a result comes on.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.