Low engine oil add oil DIC message???

[Taheezy_88]

I have "low engine oil add oil" in my dash display. My engine oil is topped off.

Anyone no the reason for this? I tried couple things to have it removed but nothing.

2007 tahoe did an AFM delete last year to success. The oil sensor in the back of the engine is new from when I did the afm delete. Anyone can help thanks in advance.

 

[iamdub]

I have "low engine oil add oil" in my dash display. My engine oil is topped off.

Anyone no the reason for this? I tried couple things to have it removed but nothing.

2007 tahoe did an AFM delete last year to success. The oil sensor in the back of the engine is new from when I did the afm delete. Anyone can help thanks in advance.

The oil pressure and oil level are two totally different sensors.

The level sensor works by the sensor completing a circuit to ground when the oil is at an acceptable level or more. If it's low, this opens the circuit and the PCM understands this as the oil being low. If there's a break in the circuit, including a failed sensor or the sensor wire becoming disconnected, it'll throw a low level warning. Check the wiring starting with the connection at the sensor, which is on the passenger side of the oil pan, about halfway up the sump. You can ground the signal wire at the connector to test the circuit and isolate the failure to the sensor. I'm trying to find a pinout diagram...


*EDIT*
Looks like it's only two wires. So, use a straightened paper clip or similar and ground one of the terminals in the connector to see if the warning goes off. If not, ground the other. If grounding one of those turns the warning off, then you know at least one of the wires from the PCM is good. Stick the paper clip in both terminals to test the complete circuit (basically just bypassing the sensor). If that works, then replace the sensor or permanently bypass the sensor.

 

[Fless]

Being the simple on/off switch that it is, with oil level full and pigtail disconnected from the sensor, you could ohm between the sensor terminals, too. If it's shorted (0 ohms) then the sensor is probably good or at least would show good oil levels all the time. If it's open, time to replace. Circuit checks as @iamdub noted, would also be good for diag.

 

[Taheezy_88]

You sir are the voice of a car God! Thank you as always. Still owe you for helping with the afm delete Iamdub

 

[iamdub]

You sir are the voice of a car God! Thank you as always. Still owe you for helping with the afm delete Iamdub

Lol Just happy to be relevant.

Have you looked into it any? If you look under there and find it plugged in securely, I'd unplug it and do as @Fless advised and ohm out the sensor. If your DVOM shows continuity even though you know the oil level is full, you have a failed sensor. Since it'll be unplugged, you can short out the terminals in the plug to keep the warning off while you acquire a new sensor. You have to drain the oil, at least a couple of quarts, to change the sensor. So, have it on hand for the next oil change. Or, permanently short the plug to bypass the sensor. '08+ don't have them.

 

[Fless]

Lol Just happy to be relevant.

Have you looked into it any? If you look under there and find it plugged in securely, I'd unplug it and do as @Fless advised and ohm out the sensor. If your DVOM shows continuity even though you know the oil level is full, you have a failed sensor.

If the switch/sensor terminals have continuity, I think that's when it's working with full oil level. From the diagrams I have, it's "normally open," meaning that's when it's not grounded (to send the "low" indication). It shorts to ground to send the full indication. Not that I've ever had one in my grubby little hands.

It would be interesting to play with a new sensor to see if sliding what seems to be a float shorts the terminals or sets them open. Anyone know if the float thing moving is how it switches?

 

[iamdub]

If the switch/sensor terminals have continuity, I think that's when it's working with full oil level. From the diagrams I have, it's "normally open," meaning that's when it's not grounded (to send the "low" indication). It shorts to ground to send the full indication. Not that I've ever had one in my grubby little hands.

It would be interesting to play with a new sensor to see if sliding what seems to be a float shorts the terminals or sets them open. Anyone know if the float thing moving is how it switches?

View attachment 370792

Good catch! I spoke it backwards, contradicting the test measures we've listed out. @Marcos Jaime_MJ, you would get NO continuity (no beep) with your DVOM if the sensor has failed. Continuity means it is working and you might have a problem within the circuit.

 

[iamdub]

It would be interesting to play with a new sensor to see if sliding what seems to be a float shorts the terminals or sets them open. Anyone know if the float thing moving is how it switches?

View attachment 370792

I think the float has a thin, weak magnet inside it that trips a reed switch inside that stem when it's within that ~1/8" of travel. I bet the PCM ignores an open circuit for a length of time (maybe a few consecutive seconds?) before displaying a warning.