20 Most Recent 2003 GMC Yukon XL - Page 4 Questions & Answers

Most of these pry off with spring loaded clips. See U-tube

lube mechanism

check trans fluid level. check shift linkage

THIS IS WHAT THE CALL TRHOTTLE POSITION SENSOR WICH IS LOCATE ON THE SIDE OF THE THROTTLE BODY THIS PS CONTROL THE IDLE ALSO CONTROL OR MIX THE OXYGEN WITH THE GAS

It could be the starter has a dead spot,the battery voltage is weak,the ignition switch itself,the antitheft passkey or the neutral safety switch..it could also be a bad brake switch.The shift /start interlock is connected to the brake switch... troubleshooting..... 1) put a test light on the small wire on the starter and see if it lights when attempting to start.if it has 12v or the test light is bright,,but will not crank,tap the starter gently with a plastic hammer,if it cranks the starter is bad.2) make sure the security light is going out.If not it is not reading the passkey and the ignition is faulty.3)when it does not start,jumper with a good battery and see if it starts if it does the battery voltage is low.4) make sure the brake lights go on with every application of the brake pedal.5)try to start in neutral instead of park when the failure occurs,if it does...the neutral safety switch is no good. best of luck

the power mirror glass is sold with the plastic back that has a round pivot that snaps into the housing.

Could be the Oil Pressure Sending Unit. I do recall GMC having issues with the instrument cluster on 2003's. Try slapping the dash when the gage reads zero.

pretty sure its the whole square thing on top of abs block on frame under seat area its old and in bad spot usually bolts don't come out you mite have to change whole thing where all lines go to.

Chances are that the hoses to and from the tank are brittle and the moving around formed a crack in a hose. Double check the connections to the tank.

Make sureyou didn't accidently unplug any vacuum lines when you had your hands inside of dash.

With engine warmed up, feel of heater hoses under hood to see if both are warm (careful don't burn yourself). If they both are warm, flapper door which directs airflow through heater is not working, probably because the actuator is bad or you have a vacuum leak. Check line under hood which goes to vacuum reservoir for vacuum, and check one way valve(check valve). Replace any old soft or cracked vacuum lines.

Wait, shuts off but still idles? If you mean does not respond to throttle, this could be a "fly by wire" system which has a gas pedal sender unit prone to failure. "Lokar" makes a nice replacement unit reportedly better than stock.

talk to a tyre retail shop as they will know what fits your vehicle, the road regulations and the correct tyre size to remain legal.

Sounds like the heater core is stopped up or bypass hose is

There are only 2 vacuum hoses on that engine Sean. One from the intake to the vacuum brake booster, One to the fuel pressure regulator. pull the small hose off of the fuel press regulator and see if gas/fuel is present. if so, replace or have the regulator replaced. typically, I find problems with the EGR tube being rotted and sucking air. this causes a lean code usually. you can spray the EGR tube to check it by spraying choke cleaner into the silver portion of the sleeve around it. if you notice the idle smooths out or picks up, you need to replace the egr pipe which includes both pipes being from the right side exhaust manifold to the intake with the egr pedestal attached to them. good luck, keep me posted on your progress

A code P0420 may mean that one or more of the following has happened:

1. Leaded fuel was used where unleaded was called for
2. A damaged or failed oxygen sensor (HO2S)
3. Downstream oxygen sensor (HO2S) wiring damaged or connected improperly
4. The engine coolant temperature sensor is not working properly
5. Damaged or leaking exhaust manifold / catalytic converter / muffler / exhaust pipe
6. Timing out
7. The oxygen sensors in front and behind the converter are reporting too similar of readings
8. Leaking fuel injector or high fuel pressure
9. Cylinder misfire
10. Oil contamination

The seat heater grid is likely shorted.