2009 tahoe 5.3 low oil pressure, power steering loss and tranny code

[metelhead]

First- Owned since day one, well cared for 295k. Tranny replaced about 100k ago.

Just recently noticed oil pressure sitting lower than usual...hovering around the 20psi (according the gauge). Historically this happens when low on oil, and a quick check and quart (or what is needed) is all that is needed to push the oil pressure around the 30's-40's.

Perhaps cause haven't been traveling much due to stay at home idk. But last week went on a day trip about 200miles and the whole time oil pressure was around the low 20's, would dip to 15 around idle. But no unusual sounds.
But the next day the Tranny coded, went into the limp mode, I checked for codes (P0700) and erased everything back to normal. P0700 is pretty generic, and I've had the stupid 'service trailer brake system' warning for the past year - inspite of changing module, every fuse etc... So I'm assuming this code was just more of the same.

Fast forward yesterday- went on a 200 mile drive (all fluids in order btw), half way through at stops or near idle the power steering stops working, but upon slighter higher revs above 1000 its fine. But the low oil pressure is again sitting around 15-22 all day. And again the tranny coded- same p0700.

Not sure if all three are related, but I'm guessing the low oil pressure and power steering are definitely related...Thinking I'm due for an Oil Pump. Just hoping its not more serious than that...

The tranny who knows, I've found the most of the warnings on these chevys mostly unreliable, and the number of interconnected dump sensors triggers has been the most frustrating part of owning and otherwise great truck.

So...any thoughts on the low pressure/power steering being related to an oil pump? Or is this a sign something more significant is up?
-could the tranny code fit into this puzzle too? Or likely unrelated?

 

[swathdiver]

First- Owned since day one, well cared for 295k. Tranny replaced about 100k ago.

Just recently noticed oil pressure sitting lower than usual...hovering around the 20psi (according the gauge). Historically this happens when low on oil, and a quick check and quart (or what is needed) is all that is needed to push the oil pressure around the 30's-40's.

Perhaps cause haven't been traveling much due to stay at home idk. But last week went on a day trip about 200miles and the whole time oil pressure was around the low 20's, would dip to 15 around idle. But no unusual sounds.
But the next day the Tranny coded, went into the limp mode, I checked for codes (P0700) and erased everything back to normal. P0700 is pretty generic, and I've had the stupid 'service trailer brake system' warning for the past year - inspite of changing module, every fuse etc... So I'm assuming this code was just more of the same.

Fast forward yesterday- went on a 200 mile drive (all fluids in order btw), half way through at stops or near idle the power steering stops working, but upon slighter higher revs above 1000 its fine. But the low oil pressure is again sitting around 15-22 all day. And again the tranny coded- same p0700.

Not sure if all three are related, but I'm guessing the low oil pressure and power steering are definitely related...Thinking I'm due for an Oil Pump. Just hoping its not more serious than that...

The tranny who knows, I've found the most of the warnings on these chevys mostly unreliable, and the number of interconnected dump sensors triggers has been the most frustrating part of owning and otherwise great truck.

So...any thoughts on the low pressure/power steering being related to an oil pump? Or is this a sign something more significant is up?
-could the tranny code fit into this puzzle too? Or likely unrelated?

The low oil pressure could be happening because of the pickup tube o-ring or just plain wear on your engine. You can test for the o-ring by adding an additional 2 quarts of oil at idle and note the oil pressure. AFM needs 22+ psi of oil pressure to operate the lifters properly. Might be time to put new bearings in the engine.

Don't know about the other two issues, I'd want to put a bi-directional scan tool on it and have a look at the trans pressures.

 

[donjetman]

I don't know about your 2009? but on my 2007 the power steering is totally separate from engine oil pressure. The PS pump is powered by a belt is the only thing in common.

 

[metelhead]

The low oil pressure could be happening because of the pickup tube o-ring or just plain wear on your engine. You can test for the o-ring by adding an additional 2 quarts of oil at idle and note the oil pressure. AFM needs 22+ psi of oil pressure to operate the lifters properly. Might be time to put new bearings in the engine.

Don't know about the other two issues, I'd want to put a bi-directional scan tool on it and have a look at the trans pressures.

Thanks James. Just YT the o-ring repair...appreciate to insight.

 

[metelhead]

I don't know about your 2009? but on my 2007 the power steering is totally separate from engine oil pressure. The PS pump is powered by a belt is the only thing in common.

Thanks Don makes sense. Seems my truck is taking this quarantine a little too seriously

 

[swathdiver]

I don't know about your 2009? but on my 2007 the power steering is totally separate from engine oil pressure. The PS pump is powered by a belt is the only thing in common.

And may protest if the engine rpms get too low, as would the oil pressure reading. Low rpms may also lead to low rpms on the transmission pump (set off generic code) too but don't know for sure. Does she drop below 525 RPMs at idle in gear or out when the pressure drops?

 

[metelhead]

And may protest if the engine rpms get too low, as would the oil pressure reading. Low rpms may also lead to low rpms on the transmission pump (set off generic code) too but don't know for sure. Does she drop below 525 RPMs at idle in gear or out when the pressure drops?

I didn't see any drop below 500-600rpm. Hmm interesting connection thou hadn't thought about the tranny pump.

 

[BG1988]

First- Owned since day one, well cared for 295k. Tranny replaced about 100k ago.

Just recently noticed oil pressure sitting lower than usual...hovering around the 20psi (according the gauge). Historically this happens when low on oil, and a quick check and quart (or what is needed) is all that is needed to push the oil pressure around the 30's-40's.

Perhaps cause haven't been traveling much due to stay at home idk. But last week went on a day trip about 200miles and the whole time oil pressure was around the low 20's, would dip to 15 around idle. But no unusual sounds.
But the next day the Tranny coded, went into the limp mode, I checked for codes (P0700) and erased everything back to normal. P0700 is pretty generic, and I've had the stupid 'service trailer brake system' warning for the past year - inspite of changing module, every fuse etc... So I'm assuming this code was just more of the same.

Fast forward yesterday- went on a 200 mile drive (all fluids in order btw), half way through at stops or near idle the power steering stops working, but upon slighter higher revs above 1000 its fine. But the low oil pressure is again sitting around 15-22 all day. And again the tranny coded- same p0700. at worst it's a faulty solenoid or "slow one"

Not sure if all three are related, but I'm guessing the low oil pressure and power steering are definitely related...Thinking I'm due for an Oil Pump. Just hoping its not more serious than that...

The tranny who knows, I've found the most of the warnings on these chevys mostly unreliable, and the number of interconnected dump sensors triggers has been the most frustrating part of owning and otherwise great truck.

So...any thoughts on the low pressure/power steering being related to an oil pump? Or is this a sign something more significant is up?
-could the tranny code fit into this puzzle too? Or likely unrelated?

you will need to get a code reader that will do transmission codes P0700 is just a request CEL..


don't be scared more then likely nothing is wrong with it just a "slow" or faulty solenoid


if you want to hear the most ridiculous thing ever I have a Faulty MAF (cracked solder or bad pig tails).. but when the MAF is acting up the transmission does not work it will sit there with the foot off the gas and revv up the engine to like 3,000 to 6,000RPM in drive while it does not even move an inch..... but messing with the MAF fixes it and it "works normally" not even a hickup from the transmission (and no disturbance from the EV to ICE translation or AUTO stop lag these people keep talking about)

also this MAF sensor provides an endless supply of random codes. :S

 

[metelhead]

you will need to get a code reader that will do transmission codes P0700 is just a request CEL..


don't be scared more then likely nothing is wrong with it just a "slow" or faulty solenoid


if you want to hear the most ridiculous thing ever I have a Faulty MAF (cracked solder or bad pig tails).. but when the MAF is acting up the transmission does not work it will sit there with the foot off the gas and revv up the engine to like 3,000 to 6,000RPM in drive while it does not even move an inch..... but messing with the MAF fixes it and it "works normally" not even a hickup from the transmission (and no disturbance from the EV to ICE translation or AUTO stop lag these people keep talking about)

also this MAF sensor provides an endless supply of random codes. :S

Haha Yikes! yeah like I said earlier these Tahoes are one electronic controller from being perfect

Update: Ended up taking to my local shop...Tranny code and PS issue seem to be ghosts. But getting the 'o-ring' in the oil pan replaced today...so should be wheels up tomorrow for a good while.