Diagnostic Aids

Check harness routing for a potential short to ground in circuit RED/BLK. Scan tool TFT display should rise steadily to about 100 °C (212 F), then stabilize.
Inspect the wiring for poor electrical connection at the PCM and transmission 7-way connector. Look for possible bent, backed out, deformed or damaged terminals. Check for weak terminal tension as well. Also check for a chafed wire that could short to bare metal or other wiring. Inspect for a broken wire inside the insulation.
When diagnosing for a possible intermittent short or open condition, move the wiring harness while observing test equipment for a change.
The temperature to resistance value scale may be used to test the TFT sensor at the various temperature levels to evaluate the possibility of a "skewed" (mis-scaled) sensor.
A "skewed" sensor could result in delayed garage shifts or TCC complaints.
Verify customer driving habits, trailer towing, etc.