GMC Cars & Trucks - Recent Questions, Troubleshooting & Support

Your anti-theft system kicked in for some reason. If you shut it off, the engine will turn over but will not start. A Chevy or GMC dealership is usually required to reset the system, but you'll have to bring it to them. Dealer + Towing = BIG $$$$. A less expensive option would be a mobile mechanic (call them first) or a licenced locksmith. Either way you'll need to show ID and proof of ownership.

Could be bad replaced.

2nd try.

• Fuel pressure is good.
• Test lamp show VCM is commanding injectors to open.

So your thought is the common side of the injectors are not powered. I believe this is the correct schematic for a '97 suburban.
There is the ECM1 fuse but hard to believe that fuse is blown, check it anyway.

Everything you mention is in the same door. Look for a connector between the body and the actuators in the door. This may be accessible or just inside the door itself, past a rubber grommet. Pull the connector apart and inspect it. Spray with silicon or WD40 and reassemble.

here ya go

Hi, from your description, the problem could lie within the fuel system. Unless it's been replaced recently, the in-line fuel filter could be clogged (after 15 years, it's overdue if it hasn't been replaced).

Vacuum cleaner

Most gms that won't back up have a split cage internally.Good thing is it is a reasonably easy fix.

You will need to contact your local GM dealer service department.

Hi, Any other issues w/the truck? Does the speedometer work ALL the time? Some of these use engine vacuum to control the Cruise. Check under the hood -around the engine - and verify the vacuum lines are all securely attached. BE CAREFUL - do this w/the engine off and ENSURE you note where all the hoses are connected. There may be a lot and easy to get them confused.

How do you know they need to be replaced ? The switches incorporate a electronic module . Driver door module .
Power Window System Components
The power window system consists of the following components:
• Driver Door Module (DDM)
• Passenger Door Module (PDM)
• Body Control Module (BCM)
• RR power window switch
• Window up and window down relays in each of the rear passenger window switches
• Window lockout switch
• Reversible power window motors in each of the doors (circuit breaker protected)
• LT DOOR CB 25A (System power for left windows)
• RT DOOR CB 25A (System power for right windows)

Power Window System Controls
The power window system will operate anytime the Retained Accessory Power (RAP) system is active or when the ignition switch is in the ACCY or ON position.
The DDM contains four power window switches which are integral components. Closing any of the normally open, rocker type switches provides the DDM with a request for power window operation. The switches for the two front windows have three positions UP, Down and Express Down, while the switches for the rear windows have only two positions, UP and Down. Each of these switches and their positions is a direct input into the DDM. Upon receiving a request for power window operation, the DDM, transmits a Class 2 message indicating the switch and it's changed position.
The PDM contains a single power window switch that is an integral component. Closing of this normally open, rocker switch provides the PDM with a request for the front passenger power window operation. The switch for the front passenger window has two positions Up and Down. Each of these switch positions is a direct input to the PDM.
The two rear passenger doors have there own switches. Each of the switches contain a power window up and down relay. A switch activation alone can control the up and down functions of the rear windows. However the BCM, upon receiving a Class 2 message from the DDM, can control the set of relays which will activate the rear window motors.


The door locks operate the same way .

Door Lock System Components
The power door lock system consists of the following components:
• The driver door module (DDM)
• The passenger door module (PDM)
• The body control module (BCM)
• The driver information center (DIC)
• The rear door lock switch
• The door lock relay
• The door unlock relay
• The liftgate lock relay--utility vehicles with liftgate only
• The reversible door lock actuators in each of the doors and liftgate
• LOCKS 20A fuse (rear lock/unlock relay supply voltage)
• ECC 10A fuse (liftgate lock relay supply voltage)


What's not working ? Windows , power locks ?
Hooking up a professional type scan tool ,not a code reader . Code reader can not read codes in the BCM or door modules . Do you know what a DTC is ? diagnostic trouble code >All these can set for door electronic problems .
DTC B1023
DTC B1544, B1600, or B1605
DTC B1580, B1590, B1610, or B1620
DTC B1640 or B1645
DTC B1722
DTC B3808
DTC B3809
DTC B3819
DTC B3820
DTC B3821
DTC B3822
DTC B3823
DTC B3824

your on the right track! your blend door is broken or your blend door actuator is broken.

You usually will not find them for free, but Mitchel, Motor, and Chilton all have wiring diagrams included in their service manuals.

You will get the wiring diagram from the given link https://toolsnyou.com

A bad master switch can do that, remove the switch from the drivers door and check for power and ground at the switch if OK replace the switch. I hope this helps. Take care.

Fun a fuel flow test on the fuel system. You may have a restriction in the lines of filter. Also make sure that nothing is blocking the accelerator peddle from opening all the way. Use a scanner and check voltage the throttle body is getting from the sender.

The best way to fix the problem is getting help from service and repair manual with pictures and diagram which will give you step by step help to locate and fix the problem on your own and you will get the manual from the given link https://toolsnyou.com

Some fixya user told me a website reliablestore it is very good.. I used it to repair my shredder it had some spark issue which wasn't easily fixed. you can go there and try