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 P0128 Or DTC P1486
2004 Acura 3.5RLSECTION DTC P0128 Or DTC P1486
WARNING: This page is about a different car, the 2003 Acura 3.2TL and 2003 Acura 3.2CL. However, it is still accessible from the selected car via links, so may be relevant.
Code Definition
- DTC P0128: Thermostat Range/Performance Problem
- DTC P1486: Thermostat Range/Performance Problem
NOTE:
If DTCs P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0300, P0301-P0306, P0335, P0336, P0401, P0505, P1106, P1107, P1108, P1128, P1129, P1259 or P1519 are also stored, troubleshoot these codes first. DTC P0128 can also set when hood is opened while engine is running.
- Check engine coolant level. If coolant level is okay, go to next step. If coolant is low, refill cooling system and repair leak.
- Turn ignition switch on. Check radiator fan. If radiator fan does not keep running, replace thermostat. If radiator fan keeps running, check radiator fan circuit, radiator fan switch circuit and radiator fan switch. See appropriate wiring diagram under ENGINE PERFORMANCE in WIRING DIAGRAMS. Repair as necessary. If circuits and components are okay, substitute known-good PCM, then recheck. If symptom or indication goes away, replace original PCM.
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.