Bump for an update and further exposure.
Since the last post, dillcc and I have been working through PMs to continue to address the issue.
We have established that there is no aftermarket alarm, remote start, etc installed and a VATS bypass has not been done. There are no other issues currently with the car or any other components. The connections to the MALL are tight and appear to be fine.
The MALL is a small thin box, probably about the size of a pack of cigarettes (maybe smaller, with two plug-in connectors (one large connector and one smaller one) that are plugged in on the long skinny side of the MALL. If you are on your passenger side floor, looking up under the dash, you should see the two connectors plugging up into the mall.
I was also thinking about grounds and the driver side buss. This is the buss that is under the carpet, by the drivers side footwell. The MALL does not use that ground directly, but some of the components connected to the MALL do.
I have typed up the internal MALL diagnostic procedures in hopes that this will guide us to a solution, but have never actually done these myself. If anyone has done these and would like to share their experience, it would be welcome.
The procedures are supposed to help tell you if there is a short in one of the components rendering the system bad.
MALL Diagnostic Procedures
Power door locks, interior lamps, and “Key-In-Ignition” and/or “Fasten Seat Belt” chime do not function
Component Diagnosis: Body Control Module (MALL)
1. Check door lock fuse (Fuse 1 - 20 amp) and chime fuse (Fuse 1D – 15 amp)
2. Check Courtesy Lamp/Power Mirror fuse (Fuse 6A – 15 amp)
3. Check for poor terminal contact at MALL and wiring harness connectors
4. Check for broken or partially broken wires.
Second Step: Perform the “MALL Module Internal Diagnostic Procedure
The MALL module stores “history” codes if an electrical short occurs in the system during vehicle operation. The codes are “communicated audibly (a bong sound) by accessing the MALL module diagnostic mode. After providing any codes, the MALL module enters a functional test mode (called Input/Output or “I/O”) to assist in verifying that the inputs to the MALL are functioning properly.
1. To enter MALL module diagnostic mode:
a. Turn ignition switch to “ON”
b. Press AND hold the power door unlock switch while at the same time…
c. Cycling the headlamp switch six times, on and off, within 20 seconds of pressing and holding the power door unlock switch
d. Release power door unlock switch
Note: (To “Exit” the MALL module diagnostic mode, turn the ignition switch to “OFF”.)
The MALL will provide a number of audible “bong” sounds (and flash the “Fasten Seat Belt” indicator light with each bong) to identify the stored history codes for any malfunctions (short circuits) as follows:
# of “bongs” Circuit Short Condition
One Fasten Seat Belt Circuit
Two Battery Protection Circuit
Three Courtesy Lamps Circuit
The MALL module will cycle through the stored history code(*) three times pausing for two seconds between each of the three cycles.
If no codes exist the MALL immediately enters the I/O mode.
2. I/O Mode:
In the I/O mode, input from components in the system are “tested” by activating/deactivating each components input device and providing either one “bong”or NO, bongs (along with flashing the “Fasten Seat Belt” indicator light) to indicate whether a “short” is detected in the circuit as follows:
Component - Test
Auxiliary Chime - Apply Parking Brake/Release, then Repeat
Interior Lamps - Turn on interior lamp switches, then turn off, then Repeat
Dome Lamp - Turn on dome lamps, then turn off, then Repeat
Door Latch Switches - LH and RH Door latch switches (not too sure on this one)
Power Door Locks - Lock then Unlock, Repeat
Battery Protection - Turn on interior lamp switch, then turn off, then Repeat
“Lamps On” Chime - Turn on headlight switch, then turn off, then Repeat
Fasten Seat Belts Chime and Indicator Light - Latch, then unlatch driver’* Seatbelt, then repeat.
Turn Signal On Reminder Chime - Activate turn signal, then turn off, then Repeat
Trunk Lid Ajar Light - Activate/deactivate trunk lid latch switch, then repeat.
If you get a “bong” when testing a component, then the component is functioning properly.
If these components check out OK, then the MALL module itself needs to be tested for a short or the module may need to be replaced.
Again, any input is welcome fellow BCers.