While zipping around in the Zero for inspections I noticed that the intake air temperature appears to be stuck at 104˚f (40˚c) with zero fluctuation. The car is drivable but it's not an ideal situation as the ECU may adjust fueling to account for temperatures.
- To verify the ECU was fine I wired in a Delphi sensor/calibration.
- Returned 78˚f with no faults. (Ambient for the evening in my garage)
- Swapped pins around for the FoMoCo TMAP. <=== THIS WAS NOT A PROBLEM AT ALL.
- No ECU faults but a very incorrect temperature (127.4˚f).
- I suspect that the TMAP is broken. <=== THIS WAS THE PROBLEM.
In the process of swapping pins I went a little too hard and snapped one of the pin catches off which will require a replacement.
- Plan A) (Plan A was the solution)
- Replace the broken connector housing.
- Replace the [potentially] broken TMAP.
- Replacements have been sourced from RockAuto.
Plan B)(Plan B was not needed.) Roll forward with the GM IAT sensor and source a GM 3-bar MAP sensor. Split the sensor ground. Has the advantage that I would absolutely know the calibration values for each sensor.
- TMAP sensor
- Original FoMoCo TMAP sensor part number
- FoMoco PN: 4S4G-8F479-AC
- Bosch PN: 0 261 230 181
- Bosch PN: 0 261 230 044