pilotincommand

@Trackrat, I thought the same with respect to battery voltage, but a charger overnight had no impact on the symptoms. As for the microswitch on the hood, when the latch is pulled, the interior lights illuminate and when the hood is latched, they go out, so I have to assume that switch is functioning correctly.

@PP000830, thanks for the wiring diagrams. I have to parse through them to see if I can locate the connectors.

However, I will check that when I get a chance.

nine9six

I agree with Trackrat's comment on battery voltage, which is why I asked the question.. Min optimal, is 12.45. Any chance of borrowing a fresh battery to recheck operation?

Regardless of various locations of micro switch operation; if there is a chaffed wire (20 yr old car) running to the frunk light, glove box light, interior lights, engine bay light; one will experience the same double flashing door top LED's and inop of the immobilizer.

pilotincommand

So its been awhile since I've had an opportunity to work on this so I still have a very expensive paperweight sitting in my garage.

Current Status:

Battery: I've verified that the battery is good (load tested and charged) and I've kept it on a charger to ensure that voltage isn't a problem.

Luggage Compartment Light: Fuse 11 is good and I get 0 Ohms from the negative terminal of the light socket to pin I/7 on the immobilizer control unit which implies no fault from the control unit to the luggage compartment light, but the bulb is still inoperable.

Dome Lights and Glove Compartment lights: work as expected: on when door / compartment open, off when closed.

Luggage Compartment Microswitch: Working as designed

Alarm codes: Through the help of fellow Rennlister Spiffyjiff, I was able to use a Durametric to pull the alarm system codes and that has added confusion. The Durametric indicated the following faults:

12: Voltage failure at terminal 30 with active alarm system
13: Voltage failure during alarm output
14: Position of the drive elements implausible
15: Door(s) open during activation (this one was true)
16: Engine compartment open during activation (not true)
17: Luggage comp. open during activation (true)
18: Glove comp. open during activation (not true)
23: Pos. switch on drive element closed during activation
24: Pos. switch on drive element open during activation (23 and 24 likely are the cause of error 14)
26: Radio contact connected to ground during activation (not true)

If I disconnect the battery for a few hours and then reconnect it, the key fob will work, but only for 30min or so and then the car turns back into a brick.

Given the oddity of the issue and the number of faults identified by the Durametric, I'm still thinking there is ground fault issue somewhere in the car, but I'm at a loss as to where it could be...

nine9six

The faults recorded are from the last time they were cleared and not necessarily all issues now. I recommend you clear the fault codes with the durametric, and see what repeats after reconnecting the fully chargrd battery battery.

Please post actual battery voltage after fully charged, rather than the battery is good. This is necessary for troubleshooting.

Are the door top leds still double flashing?

I'm beginning to think this is battery or ground points related. Since everything works as it should for 30 mins. Please record and report battery voltage, after the 30 mins., and things no longer operate correctly.

I suggest you locate all the ground points and clean and reconnect. Per a recent post, the ground wire to the battery can look good on the exterior, but have a heavily corroded core, which caused all kinds of issues.

These also could be key to your issue...Could be seen as open, despite being physically closed.
16: Engine compartment open during activation (not true)
18: Glove comp. open during activation (not true)
26: Radio contact connected to ground during activation (not true)

pilotincommand

Battery: Battery Voltage this morning was 12.89V immediately after removing the charger. Key fob worked to lock/unlock the car and I got a double flash on the door LEDs. Will check voltage again after work to see if there is a draw on it from somewhere.

Grounds: Agreed, I need to remove, check, and reconnect each ground point to ensure a good connection. However, the points I've checked so far, including the battery ground strap, have all shown 0 Ohms.

nine9six

OK, since you still have a double flash led, there is a handshake communication error within the system, but the car may still start, does it?

BTW, I believe there is a fuse in the alarm module under the passenger seat. Can you verify if the fuse is still good, or blown?

There is also a clutch pedal microswitch within the circuit. Is this functioning properly?

pilotincommand

Thanks, I'll check the fuse in the alarm module and the clutch microswitch.

nine9six

OK...Will your car start with a freshly charged battery?

p.s. I went back to your original issue posting and this stood out for you and I both.

Noticed that luggage compartment light is inoperable. Bulb is good, 12v at positive bulb terminal. Dome lights work and come on when hood is raised.

You may very well have a chaffed ground wire to the frunk light. I had this issue and managed to isolate the chaffed area doing point to point on sections of the ground wire and solve the issue with a coupla shrink wrap tubing lengths over the chaffed area, after electrical taping.

Would a faulty luggage compartment ground cause a complete failure of the immobilizer and central locking?

In my instance, no. I had double flashing led door top lights, but my fob worked with the central locking (lock and unlock). However, the alarm would not self arm, or go off when the key was used to open the door.

Also, I did not have the immobilizer light illuminating and then going out in the speedo, as it should. I believe this indicates a successful handshake between the alarm and immobilizer.

Because of all this, I could not program another fob to work with my car, until I got it all squared away.

Hopefully this info helps you in troubleshooting.

pilotincommand

Latest:

Battery Voltage (measured last night and again this morning) is stable at 12.56V. As expected, after sitting for the day, the key fob did not open the doors and the car will not start.

The fuse on the alarm module is good.

nine9six: regarding the luggage compartment light, where was yours chaffed and how did you access that wire in the loom? I'm really not looking forward to the amount of disassembly that seems required to get access to the luggage compartment and passenger compartment wiring looms for fault isolation.

nine9six

I was fortunate enough to find my chaffed wire within about 18" - 20" of the fronk light connectors, so I did not have to go back to the loom.

Quick question...When you turn your key to the position where systems checks illuminate on your dash, does the "fob image" in the clock display, go ON to check the system and then go off?

Pilot, are you located in Socal area?

pilotincommand

nine9six, not in SoCal. Rockville, MD (just north of Washington, DC)

nine9six

Pilot,
I saw this regarding battery current draw...

https://rennlist.com/forums/993-foru...ery-drain.html

See post #6 by Tore...He's very knowledgable.

txhokie4life

I had an issue with the switch not engaging when my engine hood was closed. The switch was fine when tested -- but the plunger wouldn't close the switch.

So the engine compartment light would stay on and the immobilizer would not release.

3 months of debug AND $400 cable and software -- finally figured it out.

I just disconnected the switch as that was the equivalent of "normal/closed".

Might try the same in the frunk.

At least if that works -- you know where to search

Mike

By that token -- if anyone searches this thread and is in Austin -- I've got the cable and software!

pilotincommand

Latest from the weekend.

All microswitches function properly: luggage compartment, glove compartment, engine compartment, and doors

Grounds: When disconnected from chassis the ground wire on the passenger side in the luggage compartment measures 500 ohms to the battery ground strap. I expected either an open or short, but not a marginal resistance. What am I missing?

Nine9six: I still need to check the clutch microswitch. Can't seem to find any reference to it on the wiring diagrams, can you point me in the right direction? Also, tried to chase down the luggage compartment light issue, but haven't found the issue yet.

pilotincommand

Also, key fob light on the dash illuminates and stays lit. It does not go out.