If the fans cycle on and off while the temp is showing hot, the engine is not overheating but rather an inaccurate reading. Hope the following test helps.
Coolant Temperature Gauge Needle Goes Past the Hot Mark
1. Turn the ignition switch OFF, and disconnect ECM/PCM connector C (31P).
2. Turn the ignition switch ON (II), and watch the coolant temperature gauge.
Does the temperature gauge needle move at all ? (you may have to watch it for about 30 seconds.)
YES - Go to step 3.
NO - Substitute a known-good ECM/PCM and recheck. If the symptom/indication goes away, replace the original ECM/PCM.
3. Turn the ignition switch OFF, then turn it ON (II) again, and watch the coolant temperature gauge.
Does the temperature gauge needle immediately go past the Hot mark?
YES - Replace the fuel and temperature gauge assembly.
NO - The temperature gauge needle went past the Hot mark after about 30 seconds or more. Go to step 4.
4. Turn the ignition switch OFF, and disconnect the gauge assembly connector C.
5. Check for continuity between ECM/PCM connector terminal C24 and gauge assembly connector terminal C2.
Is there continuity ?
YES - Repair short in the wire between ECM/PCM connector terminal C24 and gauge connector terminal C2.
NO - Replace the fuel and temperature gauge assembly.
Monday, January 12th, 2009 AT 7:19 AM