How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), GMC Mechanic
Category: GM
Satisfied Customers: 29523
Experience:  GM Grand Master Technician 2007. 14 years experience.
10949255
Type Your GM Question Here...
GM Tech (Cam) is online now
A new question is answered every 9 seconds

2001 GMC c2500: AUTO TRANS..HYDRAULIC RELEASE..PARKING BRAKE..RELAY

Customer Question

2001 GMC C6500 "TOP KICK" WITH AUTO TRANS, ELECTRONICALLY CONTROLLED SPRING-APPLIED CABLE, HYDRAULIC RELEASE, DRUM PARKING BRAKE ON REAR OF TRANS, WILL NOT RELEASE. REPLACED 3-WIRE PRESSURE SENSOR SWITCH. MOTOR DOES NOT AUTOMATICALLY RUN, WILL RUN IF ITS RELAY IS BYPASSED. CANNOT FIGURE OUT DIGITAL READOUT ON ELECTRONIC CONTROLER IN CAB, BY LEFT SIDE. NEED SCHEMATICS AND DIAGNOSTICS ROUTINES FROM FACTORY MANUAL. CAN DO THE WORK AND PARTS REPLACEMENT MYSELF. THANKS.
Submitted: 6 years ago.
Category: GM
Expert:  GM Tech (Cam) replied 6 years ago.

Hi, I'm Cam. May I ask your first name?
I am working to get you a fast accurate answer. About your vehicle,

Object Number: 651163  Size: FS

Object Number: 651165  Size: FS

 

Customer: replied 6 years ago.
in step # XXXXX we need the paper for diagnostic system check parking brake and with that we "should" be satisfied
Customer: replied 6 years ago.
Victor was a an out of work mecanic that I hired and he has found another job fixing busses in Aurora IL. My name is XXXXX XXXXX I own the truck that has the problem. To this day I have been having problems and I will explain from scratch. in the begining the audible alarm would sound and the brake would engage. at first I would turn off key and restart and the brake would disengage After several times I was driving when the parking break went on all by itself and inorder to get back to my warehouse I had to remove the cotterpin at the driveshaft My mecanic friend Bob is helping me get this truckback on the road and we now have a 2002 service manual whitch apears to has the same wireing diagrams What is a probable cause and where should i Check first or have you fixed this problem in the past with a solution that we can use. All we have is an OBD2 scanner that does not have truck software. 2 idot lights are on "Emergency brake" "and Service park brake" (and we hear a cliking noise near the computer when the light idot flickers). On the PBCM control we grounded the 2 pins to see the led code and all it did was flash 00 00 00 00. Is there some other procedure or is there some other method of code retreival?
thanks:
Jeff &
Bob
Expert:  GM Tech (Cam) replied 6 years ago.
You need to use a scan tool for this. A scan tool is very different than a code reader. Scan tools are larger, can scan and control certain systems of the whole vehicle, and usually cost about 2000+. A code reader will only read emission related codes and that limits them to reading the engine and transmission modules. Given the cost of the scan tools, it is usually cheaper to get a shop to read the codes. If they are honest, I would imagine that $20 is fair to stick the machine on and read codes.