DTC 1889 Oil Pressure Sensor

[G.I.Ceo]

This was suppose to be DTC 1189. So I started getting this code a few days ago. What would happen if I keep driving with this code keep popping up? I have reset it and it keeps showing up each time. I also was wondering if after market accessories can cause this to flash or even oil that needs to be replaced? I'm hoping this is just a bad sensor and as easy as a $8.00 part.

[Cliff8928]

Are you running the stock PCM? P1189 was only used in 2000 as I can see in the service information.

[G.I.Ceo]

I have a 02 with a tuned PCM and a ton of mods and added accesories on it. I have been running with these mods for a while and just started this code recently.

[Cliff8928]

Well, either way it has to do with the oil sending unit. Is your oil pressure light ever on?

[G.I.Ceo]

No my oil light has never came on just SES which gives me the code.

[sleepyalero]

Bad sensor maybe?

[G.I.Ceo]

I'm hoping its a bad sensor because it could be a lot of things and if it's just a sensor I will be happy will that. The thing is though I never get a a oil light from it or anything else. My oil filter is primed so I can't imagine it's my pump unless my oil is so bad from sitting al winter that I need to change it. Also I just changed my LIM/UIM to ported ones's and had all the push rods pulled out. I was also wondering if I am not getting enough compression or lift on a lifter or push rod would this cause the sensor to give a code? When I first started it up after doing all the work and upgrades I did get a squeal out it for a little bit but it has gone away since then and hasn't comer back. I have not reset the code since then either.

[a.graham52]

DTC P1189
Circuit Description

The engine oil pressure switch closes and the signal circuit is low with low oil pressure. The engine oil pressure switch opens and signal circuit is high with oil pressure above 4.5 psi. The PCM monitors the oil pressure switch signal circuit and sends a class 2 message to the body control module (BCM) indicating the switch status. The BCM sends a message via the class 2 serial data circuit to the IPC in order to illuminate the low oil pressure indicator.

Conditions for Running the DTC

• The following DTCs are not set:
- P0117
- P0118
- P1111
- P1114
• The ignition is ON, with the engine OFF.
• The engine temperature is 10°C (50°F) less than the last key OFF temperature.
Conditions for Setting the DTC

• The PCM detects that the oil pressure switch signal circuit is high.
• The above condition is present for greater than 10 seconds.
Action Taken When the DTC Sets

The PCM stores the conditions that are present when the DTC sets as Failure Records data only. This information is not stored as Freeze Frame data.

Conditions for Clearing the DTC

• The DTC becomes history when then conditions for setting the DTC are no longer present.
• The history DTC clears after 40 malfunction free warm-up cycles.
• The PCM receives the clear code command from the scan tool.

[G.I.Ceo]

Thanks for that but I do know this because I have a GM service manual and a DHP tuner to scan it with. I am just wondering if having a faulty switch will cause any issues while I still drive with it like that. It's not easy to get to because of my headers and it looks like I will have to take off my front headers to get to it. I have S&S headers on this thats why I am saying i will have to take them off. Also I did notice that the switch is really close to the header and i looked for a melted wire and didn't find anything.

[a.graham52]

i would assume if your low oil lights not on and your not hearing any funny noises i wouldnt be concerned.

[G.I.Ceo]

Maybe what I should to do is clear the code and fire it back up and see what it does. I know I definitely needs to have a oil changed really bad. It seems but what I have read that these switches are known to fail. Another one of GM awesome design's.

[a.graham52]

clear it and see what happens but by the sounds of it you have already done that and its just going to come back. seeings how the code is pretty much a "circuitry fault" code, then i dubt it would have ANYTHING to do with the mechanical parts of the engine. of it was your oil pump or a blocked passage then you would have your engine oil light would be on.

[G.I.Ceo]

Yeah your probably right and I haven't had a oil light at all.