20 Most Recent 2008 GMC Yukon Xl 4WD Questions & Answers

DTC P0521: Engine Oil Pressure (EOP) Sensor Performance The engine oil pressure (EOP) sensor changes voltage based on the engine oil pressure. The EOP sensor is a 3-wire sensor comprising of the signal circuit, the low reference circuit and the 5-volt reference circuit. The engine control module (ECM) supplies 5 volts to the EOP sensor via the 5-volt reference circuit and provides ground via the EOP low reference circuit. The ECM monitors the signal circuit of the EOP sensor to determine the EOP sensor voltage is within the normal operating range of approximately 1-4 volts. When the engine oil pressure is high, the EOP sensor voltage is high and the ECM senses a high signal voltage. When the engine oil pressure is low, the EOP sensor voltage is low and the ECM senses a low signal voltage. The ECM sends the EOP information to the instrument panel cluster (IPC) via GMLAN serial data message. Conditions for Setting the DTC P0521 The ECM detects that the difference between the predicted oil pressure and the actual oil pressure is either less than 47 kPa (6.8 psi) or greater than 50 kPa (7.3 psi). Your best bet ,take it to a qualified repair shop that has the proper diagnostic testing equipment to diagnose this.

What are you going by to determine it has low oil pressure ? Instrument cluster gauge , low oil light ? Have you had a mechanical pressure gauge hooked to see what the pressure really is ?

check bearings condition and adjustment

CLUSTER IS BAD, OR GUAGE FUSE IS LOOSE. CLUSTER CAN BE REPAIRED BY SOUTHERN AUTOTRONICS IN RICHMOND VA.

It sounds more like a possibly bad CV joint in an axle shaft or internal differential problem. There is no mechanical linkage to the front axle, its all electronically controlled. The front suspension is pretty good there aren't a lot of rattle type noises created from it. I need more info to diagnose better. Does it do it only moving? or stopped? over bumps only? in 4wd only? while turning? certain gears or speed only?

hub bearing or possible front differential

Look in your users manual that came with you Yukon. If it has provisions, you should be able to locate this wire harness just below steering column or alittle to the right.(they at least give you room to get in so you dont hit your knees, where they usually mt. it.) Good luck, best regards.

Here try this site, eHow. There are instructions are for a Tahoe, (model has same doors).

usually problems like that are fuel related like a stopped up filter or something next time it happens check your fuel pressure while it is broke down.

sounds like a bad connection on the battery cables

drive the auto for 1 hour then take it to the dealer and have them check it out do not turn off the vehicle when you arrive leave someone in side until they can service you sittuation

check your spare tire for proper inflation its tripped me up before

If you are touching the brake pedal while in Mountain Terrain thats normal.

This is controlled by a solenoid in the transmission. You need to have the transmission checked.