20 Most Recent 2003 Hummer H2 Questions & Answers


Make sure the shift cable is properly moving the transmission into park.

2003 Hummer H2 | Answered on Sep 16, 2019


Acceleration issue can point to many potential problem, from a tune-up to emission sensors.

2003 Hummer H2 | Answered on Sep 16, 2019


That means your horn and electrical to the horn are good. You may have a bad clock spring under the steering wheel, or a bad switch. Don't forget to check the horn fuse. It may have a different circuit than the FOB.

2003 Hummer H2 | Answered on Aug 25, 2019


Pretty common problem with these. Here's a guide to learn how to fix GM instrument clusters yourself, I used it to fix mine and it worked great.How to guide for Silverado instrument cluster repair
Pretty common problem with these. Here's a guide to learn how to fix GM instrument clusters yourself, I used it to fix mine and it worked great.How to guide for H2 instrument cluster repair

2003 Hummer H2 | Answered on Aug 24, 2019


That's not how wiring diagrams are drawn. They're drawn by system, not location. See this post on how to get the diagram you're looking for

2003 Hummer H2 | Answered on Aug 24, 2019


Do you have an air bag light lit on the instrument cluster ? Do you have C.C. button's on the steering wheel , do they work ? If the alarm fob (as u call it ) Can make the horns sound , the relay is sending B+ voltage to the horns Don't know how your testing.
System Description
The horn system consists of the following components:
• Horn fuse
• Horn relay
• Horn switch
• Horn(s)
• Body Control Module (BCM)
System Operation
The vehicle horns are activated under the following conditions:
• The horn switch is depressed.
• The body control module (BCM) commands the horns on. The BCM commands the horns on under either of the following conditions:
- When the content theft deterrent system detects a vehicle intrusion. For further information, refer to Content Theft Deterrent (CTD) Description and Operation in Theft Deterrent.
- When the panic button is depressed on the remote control door lock transmitter. For further information, refer to Keyless Entry System Description and Operation in Keyless Entry.
- When the OnStar® system is used to sound the horns, if equipped. For further information, refer to OnStar Description and Operation in Cellular Communications.
- When the keyless entry system is used to lock the vehicle, a horn chirp may sound to notify the driver that the vehicle has been locked. The notification feature may be enabled or disabled through personalization. For further information, refer to Keyless Entry System Description and Operation in Keyless Entry.

Circuit Operation
Battery positive voltage is applied at all times to the horn relay coil and the horn relay switch. Pressing the horn switch applies ground to the horn relay control circuit. The body control module BCM may also apply ground to the horn relay control circuit as described above. When the horn relay control circuit is grounded, the horn relay is energized and battery positive voltage is applied to the horn(s) through the horn control circuit. The horn(s) sound as long as ground is applied to the horn relay control circuit.

2003 Hummer H2 | Answered on Aug 24, 2019


Go to local dealer, parts department, ask staff to print an assembly diagram which includes all the parts and how they connected to the others, from it, you can see where the bolt/nut are, you can then remove and install a new one if it can be accessed, you decide to diy or hire mechanic for it.

2003 Hummer H2 | Answered on May 18, 2019


Wiring problem under the dash. Could be a ground issue as you said. You need to get under the dash and check the grounds.

2003 Hummer H2 | Answered on Sep 22, 2018


Dear Gail,
It is time to find out why you have an electrical problem, before it all gets worse.
Please do not be surprised or discouraged when no one can find the problem.
When you say "intermittent", you are right, but that makes it ever so hard for the mechanic to find, much less to fix.
God bless your efforts.
(Over the last 50 years, I have had to occasionally carry my own extra battery and jumper cables in the trunk of my car when no one could find the problem.)

2003 Hummer H2 | Answered on Apr 29, 2018


2003 hummer
If you have trouble in fixing your vehicles, try this link. Very helpful

2003 Hummer H2 | Answered on Jan 18, 2018


Check if any mute function is not activated.

2003 Hummer H2 | Answered on Oct 18, 2017


A scan tool should be able to read the temp pids at operating temperature to see if they are "off" enough to cause problems . Check for fuel lines to close to heat sources as boiling of the fuel causing vapor lock may be happening after heat soaking .

2003 Hummer H2 | Answered on Aug 16, 2017


Unless you have issues, the fluid is sealed for life.

2003 Hummer H2 | Answered on Aug 14, 2017


The first thing should be to have it check for DTC'S - diagnostic trouble codes . Could have ignition switch problem , a shorted sensor bring down the class 2 data serial data network , the control modules all communicate on this data network . The starting system on this vehicle is controlled by the PCM - engine computer ! When you turn the key to start a voltage signal is sent to the PCM , if the PCM sees a voltage signal from the transmission range sensor and thier is no anti-theft system problems the PCM will energize the starter relay .
012 GM Class II Communications
There is also a direct redundant class 2 serial data circuit between BCM and PCM.
The following modules communicate on the class 2 serial data circuit:
• splice pack - SP205 attaches to:
• Air Suspension Module (ESC)
• BCM
• DDM
• EBCM
• FPDM
• HVAC Control Module
• IPC
• PCM
• Radio
• TCSCM
• splice pack - SP206 attaches to:
• Audio Amplifier
• RSA Control
• VCIM
• splice pack - SP207 attaches to MSM-Driver and SDM
Hooking up a scan tool an checking scan data would be a first step . Testing electrical connections , B+ voltage at the fuse boxes ,main power feeds etc. Looking at wiring diagrams an power distribution diagrams . Using a voltmeter to test with.
Electric Testing Techniques You Need to Know
Free wiring diagrams here http://www.bbbind.com/free_tsb.html Enter vehicle info. year , make , model an engine ! Under system click power distribution then under subsystem click on power distribution . Click the search button then the blue link. Look at the power flow path an test with volt meter . Could be something simple but then again ! The complexity of the modern vehicle is well above most peoples scope .

2003 Hummer H2 | Answered on Jun 20, 2017


The shift cable is off the lever on the trans...the dash indicator states drive but the shifter is in park. Look under the drivers side of the trans, next to the catalytic converter(make sure the truck is cooled off) the trans cable will not be attached to the tranny lever-re-attach and you will be able to get it home or to a shop for a repair. This happened to me already, simple fix.

Rob Davis
2003 H2

2003 Hummer H2 | Answered on Jun 19, 2017


its normal. its also bad for the drivetrain to use it in 4wd on dry pavement

2003 Hummer H2 | Answered on Jun 13, 2017

Not finding what you are looking for?

832 questions posted

Ask a Question

Usually answered in minutes!

Popular Products

2005 Hummer H2
2005 Hummer H2

221 Questions

2004 Hummer H2
2004 Hummer H2

152 Questions

2006 Hummer H2
2006 Hummer H2

106 Questions

2009 Hummer H2
2009 Hummer H2

11 Questions

Top Hummer Experts

Marvin
Marvin

Level 3 Expert

85178 Answers

Jonah Oneal

Level 3 Expert

14092 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22484 Answers

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

Answer questions

Manuals & User Guides

View Most Popular

H2 Hummer

  • H2 Hummer

Most Popular Question

03 humer h2 rattle starting 40mps

  • Cars & Trucks
Loading...