What does the PCM do with the fuel temp info?

[Hubert]

What does the PCM do with the fuel temperature measurement related to the optic sensor? Does it offset injection for starting or affect fuel map?

I have read the mechanical pumps will hard start when old/worn and hot but haven't read the same of the DS pumps. I can see the density/viscosity of fuel appeciably changing over the expected temp range of ~40-180F.

[More Power]

Diagnostic Trouble Codes P0182 & P0183 are associated with the fuel temperature sensor, which is a component part of the Optical Encoder Sensor.

DTC P0182 will set if the sensor voltage, as detected by the PCM indicates the fuel temperature has exceeded 102 degrees C or 215 degrees F. Sensor voltage decreases as temperature rises, so this code could also appear if the sensor wiring has become shorted to ground.

DTC P0183 will set if the opposite occurs. An abnormally high voltage could indicate an open circuit.

The various manuals I have discuss how to troubleshoot and repair problems that produce these codes, but they don't discuss what the PCM does with the information otherwise.

We can theorize. Hot thin fuel is bad for the injection pump from a wear standpoint, and hot thin fuel can produce a hard to start hot condition. And lastly, fuel is what Stanadyne uses to cool the pump electronics. I suppose it's possible for electronic failures if the fuel temperature exceeds the high limits mentioned above.

From within the Tech II Scan Tool data lists, the fuel temperature is found within the MAF/EGR data list. Typical data should range from 50 degrees F to 194 degrees F.

There is no mention whether the PCM would put the vehicle into limp mode if either P0182 or P0183 set.

Jim