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I just completed the GPR led mod and have a couple questions. Here in Miami the temp is about 73* and sunny and just got back from the store so the truck is still warm. Upon completion the light does not light up. Does it have to be cold so the GPR starts to work or does it work always on start up and my GPR is bad? How can I check to see if the GPR is working like it should? The 1/2 nut, that the led red wire goes attached to it has no power to it, does it have to be powered always?
George, the PCM commands the time that the GPR should be on based on this graph:
The PCM uses input from the BARO (barometer) sensor and the EOT (engine oil temperature). So my guess is after driving your truck, the EOT got above 131 degrees F. Therefore, the PCM would NOT command the GPR to close and the LED would NOT light.
So you hooked the light to the cold side of the GPR correct? That is where it should be connected with the second wire from the LED running to a ground (I used one under the dash). Tomorrow morning when you turn the key to the KOEO position, the LED should lighht and stay lit until the PCM commands the GPR to open.
I think its normal George...
I just did my gpr led and it does the same thing after it gets warmed up...
Thought i had a ground problem until i checked everything out and circuit tested good.
Well, its cool enough now and just tried it..........no dice. going to have to check it out mañana ...........one large pole has juice, the other no juice.
Well, its cool enough now and just tried it..........no dice. going to have to check it out mañana ...........one large pole has juice, the other no juice.
If you still have doubts in the morning you can switch with the AIH relay, at least confirm if it's working. Or jump the terminals.
Mine here in Houston usually won't come on after morning, engine will hold some heat.