2006 MX-5 57k Miles USDM 2.0L 6-Speed

P0126 and B1318 Set but no light on/Sporadic illumination.

Coolant reservoir is full.


That site references that there's a TSB available regarding the ECT/CTS, but I am unable to find any TSB's relative? Looks like it is TSB: 01-001/06?

Any other suggestions?

Other than not being able to get to the alternator output, I performed a drop test. All was well. 13.87 while running; Concerning?

Thank you for your time.

Freeze frame report generated by Torque for Android

Vehicle VIN: JM1NC25F060119xxx Vehicle Manufacturer: Mazda Vehicle Calibration ID: LFN4EG000LFN6xxx

Freeze frame information:

Fuel Status = 0 byte

Engine Load = 14.51 %

Engine Coolant Temperature = 159.8 °F

Fuel Trim Bank 1 Short Term = 0 %

Fuel Trim Bank 1 Long Term = 0 %

Intake Manifold Pressure = 2.756 psi

Engine RPM = 1,886.25 rpm

Speed (OBD) = 38.525 mph

Timing Advance = 10 °

Intake Air Temperature = 78.8 °F

Mass Air Flow Rate = 3.44 g/s

Throttle Position(Manifold) = 12.157 %

Run time since engine start = 1,128 s

EGR Commanded = 0 %

Fuel Level (From Engine ECU) = 68.235 %

Distance travelled since codes cleared = 166.527 miles

Barometric pressure (from vehicle) = 14.504 psi

Catalyst Temperature (Bank 1,Sensor 1) = 721.94 °F

Voltage (Control Module) = 13.581 V

Engine Load(Absolute) = 10.98 %

Commanded Equivalence Ratio(lambda) = 0.996

Relative Throttle Position = 3.137 %

Ambient air temp = 73.4 °F

Absolute Throttle Position B = 12.549 %

Accelerator PedalPosition D = 31.765 %

Accelerator PedalPosition E = 20.784 %

End of report.

  • 1
    The B1318 seems to relate to battery voltage being too low ... While a running voltage of 13.5vdc at the ECU may not be bad, I'd double check it with the engine running. It should be up over 14vdc by a bit. Also, your fuel trims are 0% on both long/short term? That's very odd. 159.8 °F is very low, especially considering the engine has been running nearly 20 mins already. Even at an idle, I'd expect it to be up to temperature ... thus the P0126 code. Maybe that's why the fuel trims are screwy. Check the thermostat to see if it's working properly. Apr 29 '18 at 12:30
  • The TSB you linked doesn't apply to the MX-5. What module did the b1318 code come out of? DSC? Like @paulster2 suggested, pull the thermostat and make sure it's working.
    – Ben
    Apr 29 '18 at 15:01

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