1999 Ford F-150 False Temp Guage reading

MYFORDF150

MEMBER
1999 FORD F-150
6 CYL
2WD
MANUAL
125,000 MILES

I have owned this vehicle for a week and put over 130 troublefree miles on it. Today while out of town it showed that it was overheating. But it didn't act like it. No engine crackling, smells, bubbling sounds etc. The needle eventually pegged past H 10 -12 miles before I oculd get home in the heat of the day. It never stopped or ran differently than what I previously observed. Smells and sounds of overheating after getting home. None. Oil level and coolantvchecked out fine. Do you think that possibly a sensor is sending errouneous information on the actual tempreture? Please advise of what you think because I don't want to burn it up.

1 Reply

MERLIN2021

MECHANIC
17,250 POSTS

TEST F: TEMPERATURE GAUGE INACCURATE 1. Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Turn ignition switch to RUN position. Trigger instrument cluster active command ENGCOOLNT. Observe engine coolant temperature gauge while adjusting ENGCOOLNT active command to read 50% and 100%. Temperature gauge should start at cold, move to half at 50% and full hot at 100%. If gauge does not read as indicated, go to next step. If gauge reads as indicated, gauge is okay. Check water temperature sender and wiring. See SELF-DIAGNOSTICS - EEC-V (GASOLINE) article in ENGINE PERFORMANCE. 2. Disconnect all instrument cluster connectors. Inspect connectors for corrosion and pushed out pins. Connect all instrument cluster connectors, ensuring they are connected correctly. Operate system and verify if concern is still present. If concern is still present, replace instrument cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. If concern is not present, system is operating correctly at this time. Clear DTCs and repeat self-test. NOTE: After repair, clear DTCs and repeat self-test.
USING HYBRID ELECTRONIC CLUSTER (HEC) To enter HEC self-diagnostics, press instrument cluster SELECT/RESET button before turning ignition switch to RUN position. Within 5-8 seconds, odometer will display "tESt" to begin self - diagnostic mode. SELECT/RESET button must be released within 3 seconds of odometer displaying "tESt". Repeatedly press SELECT/RESET button through odometer displays until dtc is displayed. When odometer displays "dtc", press SELECT/RESET button again and any continuous DTCs will be displayed before odometer advances to next display. Other HEC diagnostic modes can be entered when self-diagnostic function is entered. See HEC SELF-DIAGNOSTIC MODES table.