Question about 2003 Chevrolet Silverado 2500HD

Open Question

Gmc 2500hd 8.1 engine error code PO840

The error code PO840 is for the trans fluid press sensor. Where is this sensor located?

Posted by Anonymous on

6 Suggested Answers

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017

  • 362 Answers

SOURCE: can't locate fluid eservoir to add trans fluid

Here how to do it: If you see no signs of leaking from the transmission then the level is probably not low, take it to a transmission shop, transmission repair on this car is not for the DYI.

Ensure that the transaxle case temperature is 70° to 90° F (21° to 32° C). With the engine running, shift transmission through all gears. With engine idling in PARK, remove the check plug from the transmission. If transmission has been overfilled, allow fluid to drain out. If no fluid drains out, add fluid through the TRANS FLUID fill cap under the hood on the driver side in 1 pint (0.5 liter) increments until it slightly flows from the check plug. Reinstall the check plug.


Posted on Jan 31, 2009

  • 75051 Answers

SOURCE: engine seems to be flooding with fuel

your engine doesn't have a MAP (Manifold absolute pressure) sensor it has a MAF (Mass Airflow) sensor, that is located in the air intake hose to the throttle body of the intake.

Posted on Jun 08, 2009

  • 302 Answers

SOURCE: why wont my 2001 gmc sierra 2500hd go into 4th gear?

Check to make sure you don't have the TOW/HAUL switch on the end of the tranny stalk turned on

Posted on Jul 27, 2009

  • 632 Answers

SOURCE: where are the knock sensors located on a 2002

Knock sensors as a rule of thumb are positioned right beside a piston on the the block. It should be on the opposite side of the exhaust system. A knock sensor is actually a sensitive microphone or listening device. It listens to a piston performance under load. If it hears a knocking or pinging sound it will ****** the ignition timing and advance it again when condition changes. It would have a securing bolt in the middle which torqued to a certain spec and a single wire harness.

Posted on Mar 14, 2010

  • 212 Answers

SOURCE: where is knock sensor located on 2004 chevy 2500Hd

Under intake manifold on top of block,you need to remove intake to access sensors there are two of them you can't miss them when intake is off. After replacing sensors you need a new intake gasket.

Posted on Apr 04, 2010

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Igot a 2004 gmc sierra 2500hd chk engine light came on so i put a obd2 can and it shows the code p0894 whats the meaning of this code?

has something to do with torqe converter fluid it may be low on transmission fluid or ya need to change transmission filter and fluid

Mar 29, 2015 | GMC Cars & Trucks

1 Answer

My 2002 GMC 2500hd with an 8.1 eng has two history codes p0101 and p0700. How do I fix it?

if it's in the transmission other than ck'ing to see if you have proper level and quality fluid level in trans theres not much a homeowner can do your gonna need to find a good trans shop
1st try getting a fluid flush and fill this is a lower cost fix that sometimes works and you don't need to remove trans to do it

Sep 16, 2014 | 2002 GMC Sierra 2500HD

1 Answer

2008 2500hd Duramax/Allison trans. Why is check engine light on?

Have codes read by someone with good scanner that reads trans codes.

Oct 28, 2012 | GMC Sierra Cars & Trucks

1 Answer

Where are the two knock sensors located on a 2002 GMC 2500HD with a 6.0 engine. Which sensor is classified as number one and number two.

Hello: There are two knock sensors under the intake manifold on top of the engine. Replace them both.

Oct 06, 2011 | 2002 GMC Sierra 2500HD

1 Answer

2002 GMC 2500HD Diesel service engine light on, automatic but won't shift gears. also shift indicator light don't work all the time

out of commision right now? sounds like it needs a new transmission, or out of fluid, but if the fluid is low or empty theres probably some dammage thats been done. i bet if you run that computer to check that code it will only confirm your guesses...

Feb 08, 2010 | 2002 GMC Sierra 2500HD

2 Answers

Have 2001 chevy 2500hd with a code 0700 bad tcm. can you tell me where it is and how much do they run.

P0700=Transmission Control System (MIL Request)
Does not mean bad TCM,=transmission control modual,
all that happen here was the computer did not like the responce it got from a sensor,and requested the check engine light be turned on.
You need to have it scanned by a shop if it reappears

Dec 25, 2009 | 2003 Chevrolet Silverado 2500HD

1 Answer

Screeching noise when I turn the wheel. What type

plain power steer fluid or auto trans fluid.

Aug 05, 2009 | 2002 GMC Sierra 2500HD

1 Answer

Can i use syn fluid in tran

yes u can, just use the new DEXRON VI (GM recommendes it for all there AT transmissions now), it is avail as a full synthtic or a blended fluid, it greatly improves trans perf and extendes the life of the trans.

Jun 16, 2009 | 2002 GMC Sierra 2500HD

3 Answers

Dtc p0342

I just replaced mine on an '04 8.1 vortec. Ez fix. Pd $33 at Rockauto. The sensor in located on the front of the engine &slightly toward the drivers side. Unplug the electrical connector and remove the single nut (10mm). Evenly pull the sensor out from the block. Only use the force needed. Don't yank. Place a oil on the new sensors o ring & reinstall.

Aug 11, 2008 | 2002 GMC Sierra 2500HD

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

50 people viewed this question

Ask a Question

Usually answered in minutes!

Top Chevrolet Experts


Level 3 Expert

75051 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22095 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

7726 Answers

Are you a Chevrolet Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides