Jim Grant's Tech Tips
'97 Pontiac Grand AM, Coolant& Check Engine Lights
Q: The coolant light is on in my"97 Pontiac Grand AM. I had the radiator flushed and it is still on. They say it's okay. My "Check Engine" light is on - the DTC ended in the number 39 but I didn't get the rest of it, and the guy at Valvoline reset it. Something about a camshaft or a crankshaft. The car is running fine. Any idea what it is? I don't want to assume it is okay just because they reset the light. The coolant light is still on.
Having a code that ends in 39 may be related to the crankshaft or camshaft position sensor. But, if the check engine light has not turned back on since it was cleared it is likely an intermittent fault or was just a bad sensor day for the car. There are 2 coolant related lights on your vehicle. One will illuminate if the vehicle is overheating and the other will illuminate if the coolant level is low. The sensor for the coolant level is mounted in the coolant reservoir and it is activated by a floating magnet. When the coolant level drops too low the magnet will drop down and activate the sensor, which in turn tells the engine computer, and the engine computer in turn, reports this information to the processor in the dash that turns the low coolant level warning light on. A lot of computer stuff just to let you know your coolant level's low. It is common for the floating magnet to get stuck in sediment and report a low coolant condition when the level is just fine. Most of the time the reservoir has to be removed and rinsed, a real good shake with clean water, to free up the floating magnet. The sensors do fail and they're easy to diagnose and replace. It would be a good thing to know if your coolant level is correct. I would suggest getting it repaired.