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Discussion Starter · #1 ·
On my way home from school last night my check engine light popped and after plugging in my OBD I got a P0128 code. Google really isn't helping, I keep getting G6's but I think i've located the sensor but I'm not sure. Is it in the back of the engine near the O2 sensor?

Car: 2007 Pontiac G5

For info about the P1028
Leaking or stuck open thermostat.
(Not detecting any leaks, but thermostat might be the issue)

Low engine coolant level.
(Coolant is at good levels)

Insufficient warm up time
(Might be it?)

Engine coolant temperature sensor harness is open or shorted.
(Already got the sensor, plans on replacing it before thermostat.)

Engine coolant temperature sensor circuit poor electrical connection.

Premium Member
12,861 Posts
Does your coolant temp read "---"?
It is more likely that the thermostat is stuck open (very common) than the coolant temp sensor being bad.
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