Oil Pressure Question
Thread Starter
Melting Slicks
Joined: Oct 2002
Posts: 2,515
Likes: 441
From: Arizona
Oil Pressure Question
I just noticed that the HUD constantly reverts back to oil pressure reading after start up even though I always have it on fuel. This caused me to start watching the oil pressure and I noticed that at idle it is at 40 and under acceleration it goes up to 60 or a little over. Two part question - Why does the HUD revert to oil pressure after start up and is the fluctuation of pressure normal? Thank you in advance.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Strongly suspect this is being caused by a low or weak battery whose voltage level drops below the minimum needed to retain the memory during engine crank and therefore drops back to default setting.
Try this. Set the DIC to display something other than the vehicle mileage, say engine temp or oil pressure etc.. Then start the engine and once running see if the DIC is displaying mileage again. If so then the battery is very suspect. While it can crank the engine, it is not retaining enough voltage to support the memory.
Try this. Set the DIC to display something other than the vehicle mileage, say engine temp or oil pressure etc.. Then start the engine and once running see if the DIC is displaying mileage again. If so then the battery is very suspect. While it can crank the engine, it is not retaining enough voltage to support the memory.
If you put a DC Voltmeter on the battery terminals and monitor it before, during and after COLD cranking the engine, you will see what we are talking about. I bet it momentarily drops below 9 VDC when you first hit the starter.Each time it drips below the operational voltage level of any of the cars modules, it causes them to shut down. This can adversely effect some relays and electrical components. It can also cause your emissions ready flags to reset and the car will not pass emissions until you drive the required driving cycles.
Check you DTCs and I bet your LDCM & RDCM have low voltage DTCs
YOU COULD HAVE ANY OF THESE Battery out of range DTCs
B0846, B0851, B2282, B2283, B2284, B2285
Thread Starter
Melting Slicks
Joined: Oct 2002
Posts: 2,515
Likes: 441
From: Arizona
Thanks. I just recently hanged the battery and now the car is completely dead sometimes and starts fine sometimes. Battery connection looks ok. But be a short or bad ground somewhere. Weird.
100% on the mark! If you put a DC Voltmeter on the battery terminals and monitor it before, during and after COLD cranking the engine, you will see what we are talking about. I bet it momentarily drops below 9 VDC when you first hit the starter.
Each time it drips below the operational voltage level of any of the cars modules, it causes them to shut down. This can adversely effect some relays and electrical components. It can also cause your emissions ready flags to reset and the car will not pass emissions until you drive the required driving cycles.
Check you DTCs and I bet your LDCM & RDCM have low voltage DTCs
YOU COULD HAVE ANY OF THESE Battery out of range DTCs
B0846, B0851, B2282, B2283, B2284, B2285
If you put a DC Voltmeter on the battery terminals and monitor it before, during and after COLD cranking the engine, you will see what we are talking about. I bet it momentarily drops below 9 VDC when you first hit the starter.Each time it drips below the operational voltage level of any of the cars modules, it causes them to shut down. This can adversely effect some relays and electrical components. It can also cause your emissions ready flags to reset and the car will not pass emissions until you drive the required driving cycles.
Check you DTCs and I bet your LDCM & RDCM have low voltage DTCs
YOU COULD HAVE ANY OF THESE Battery out of range DTCs
B0846, B0851, B2282, B2283, B2284, B2285
Thread Starter
Melting Slicks
Joined: Oct 2002
Posts: 2,515
Likes: 441
From: Arizona
Thank you. Ill try cleaning the battery connections with some steel wool. No headers (unfortunately, ha). Thanks again.
Check to make certain the battery cables are tight and clean. If yo can move the cables by hand they are NOT tight enough.
Does the car have headers?? If yes then check ALL the connections at the starter. Lots of recent threads by posters who have had poor/loose or burnt connections at the starter. Check the negative battery cable connection at the block while you are at it.
Does the car have headers?? If yes then check ALL the connections at the starter. Lots of recent threads by posters who have had poor/loose or burnt connections at the starter. Check the negative battery cable connection at the block while you are at it.
