1) So you had rat feces in the floor and trunk and the outside temperature readout is showing (what amounts to) a disconnected probe - if the temperature reading worked when you parked the car, then added to what I am reading here - you have damage to the wiring harness of the car. UNLESS the probe came unplugged when you were crawling around under the front of the car. If you haven't been crawling under the front of the car, I suggest you do so NOW and see if that plug is unplugged. If it is not unplugged, then the wiring has probably been chewed.

Keep in mind that when you find the chewed wires to the probe, there may be more damage elsewhere if the damn thing was in the trunk! Hopefully, it chewed the probe wires and what ever wires are not allowing the pulse module to to it's job in the same place in the car.

2) If, by some wonderful miracle, a rat has not chewed the hell out of the wiring in the car (and we can pretty much assume so, but let's entertain the unlikely event that you don't have chewed wiring) - then this goes back to the pulse module. I am not saying the pulse module is bad, I'm saying that the pulse module is not sending pull-in current to the solenoid and we must determine why this is.

I cant stand the awful wiring diagrams that we are stuck with, but here is how I understand the pulse module:

12 volt battery power is applied on A1
Ground is A5
Switched 12 volt power is applied on B2
The "Start" signal from the ignition switch passes thru the clutch switch (if a manual) then on to B1

If you have all of the above, then PROVIDED the PTCM enables the Pulse Module, the starter engages, because 12 volts shows up on F1.

When the engine reaches 450 rpm, the pulse module is disabled by the PTCM. (This is why you can turn the key to "START" with the motor running and the starter does not engage).

The way I read the book, the "enable" is a ground that the PTCM puts on A2 and the "disable" is the removal of a ground by the PTCM on A2. I would like to prove this by making measurements on my car - but my car is in a storage facility 4 miles from home. And as long as it is raining, I'm not getting the car out! I have some time off coming, if the weather clears on Wednesday or Thursday, I will run out there and see what I find.

But ya got chewed wiring, I am just SURE of it. I HOPE I am wrong.

 

Pizzaguy,


There went my half full glass!


I started this absolutely certain that the rat had done me in. I've been everywhere under the hood and under the front portion of the car, and found no evidence of rodent damage. I've rolled back carpet and foam in the right footwell, and found no hint of damage. No bad wires, and no little plastic confetti. I have the underside of the dash cover disassembled enough to test the clutch switch, and can find no damage on that side.


I'm pretty much right with you on the pulse module function and wiring. I have some items to check tonight. At the same time the ignition switch sends fire to the pulse module via the clutch interlock, it also sends power to the pulse module directly, AND to the PCM from the clutch module. I need to trace and check those. I had not checked the hot from the battery to the pulse module, or the ground. I understand both better now, and will check. It may be that the wire from the clutch interlock to the PCM is rodent damaged, or some other stray sensor is damage and the PCM is unhappy. I at least have more to rule out.


The temp sensor wiring seems to be perfectly intact. Could be a bad sensor, from being nearly submerged for much of the last trip, or a rat-damaged wire, or something unrelated. How many of these doodads are wired to disable the car if they fail? I could happily drive it for a while without an outside temp reading.


Please offer any ideas as they occur. I'll stay at this, and maybe end up finding something interesting or even useful.


Michael


Once all the scars heal, I think I'll appreciate this car even more.

 

For anybody still looking - I did chase the wires going to the pulse module, and checked voltages and grounds. All were as designed except the 12 gauge violet out to the starter solenoid. I measured 12V on the sensor ground connected to the PCM; I don't know how to interpret that.


At the clutch interlock, 12V violet splits and goes to the pulse module and to the PCM. After a lot of looking and probing, I think I measured the right wire, and got about 5mV on the violet at the PCM, rather than 12V. It may be that I can run another wire, at least temporarily, from the clutch interlock switch to the PCM to ensure I have the proper voltage. Maybe I found what the rat ate.


More as it happens.


Michael

 

Black 05 Roadster Limited, no longer for sale!


Finally was able to determine that the wire from clutch interlock to the PCM had no voltage at the PCM. Got up the courage to temporarily splice into the wire at the PCM and jumper from the violet at the pulse module that supplies 12V from the ignition switch during "start." It started immediately and ran perfectly.


I can see most of the wire, or the harness that contains it, with no evidence of damage. Will now have to decide to either disassemble and trace the wire where I can't see it now, or cut the suspect wire out and splice in new. That is easier and less intrusive, and is my most likely path.


Temperature is still -36 with the sensor unplugged. I still have to check voltage and ground to determine if the wires are good before buying a new sensor. I'm hoping for a bad sensor, but suspect more damage in the dash.


Otherwise, Cathy checked most of the controls and switches while I watched for smoke, and we found no other trouble or malfunction, except half of the brake light. That may be completely unrelated and I'll deal with it later.


Thanks to all who helped me troubleshoot this. At a dealer, this repair might have exceeded the cost of replacing the car. I bought a battery I didn't need yet, but I needed one for the tractor, so no cost against the car. I bought a used pulse module I didn't need, but it gave me more than $40 in education, and helped me work through the logic of the starting circuit. I repaired solder joints on the RCM that should already have failed. The biggest expense has probably been Tums/Rolaids/Prilosec.


Michael, black 05 Roadster, limited, 6spd, NOT FOR SALE

 

That's GREAT news Michael, but I guess this means you won't be hauling it over so we could meet.
Enjoy it, and we'll meet someday, don't know where, don't know when, but I'm sure we'll meet some sunny day. ( )
( BTW, on the roadster 3rd brake light, the guy up in Tennessee can fix it for @ $120.
Cadillac LED Replacement 3rd Brake Light, High Mounted Stop Lights, Third Brakelights For Escalade, Escalade EXT, LTZ, ESV, XLR, Seville, SLS, STS, Chrysler Crossfire, Lexus SC 300 400, Hummer H3 )

[ I got the RCM back ]

 

Excellent news, as a side note, the clutch interlock also allows for cruise control to let off when you shift, then resume. It actually works very well with the 6sp

 

Thanks for the info on the brake light and regarding the cruise control. Didn't know about either, but I knew the lyrics to the song very well, though I couldn't have named the singer. Some of the worst punishment for me as a kid was to have to sit through Lawrence Welk. Now I have become my father, and am hooked on big band, swing, and even the late 50's lounge music.


I may take a stab at the brake light. It is clearly internal and probably bad solder joints. If I can't get in, it will go to Tennessee.


Lot's of cleanup and reassembly to do now. Finally.


Michael

 

Nice work! Individual open wires are tough to find.

 

Perfect fix! Thanks so much for the detailed instructions! Fired right up after the solder job was complete.

 

The engine light was on and off, until he was always on.
I have checked all the secondary air injection system, secondary air pump, vacuum check valve, air pump relay and all works perfectly.
I dismounted the PCM and checked all the welds, I saw that the welds belongin to the secondary injection system relay had cracks.
The welds are situated on the right corner.
I resoldered these welds and checked the status of the relays.
I saw the relay located on the left side (is the secondary injection system relay) had the contacts burned, I cleaned the contacts carefully with a fine sandpaper.
I installed the PCM in its box and checked the operation after repair.
The engine light come out and the problem is solved.


thanks very much for your help

 

Did you ever check for codes?

 

I cannot believe my eyes (and ears)!!! Thank you so much for your expertise, and a massive shout out to Tighed1 for the step by step photos for this RCM fix.

I just cannot believe that the car that I have been fixing up for 3 years, (massive rear damage when bought) fired up as soon as I tried this fix.

3 small dabs of solder!!! Unbelievable!!!

I am speechless, you have absolutely made my week!!!

Many thanks, this is what the internet is made for!!!

 

I just saw this, I want to be there when you two meet and catch that brotherly kiss and post it here for posterity. Meet at the Dragon and share a room maybe.

 

Too late, already sharing a room with Max ( maxcichon )
3 would be a crowd.

 

Hey-if I'm in the way...

 

Yes I did, the error code was PO 410 Secondary air injection system malfuntion.
After to repair the PCM, the error code disappeared, and now no moore error codes.

 

Just completed this mod. Used a watch maker's magnifying headset because you get much better magnification. End result is that it worked great. It was easy to see the poor original solder connections. Nothing more than too little solder which allowed vibration to break the joint intermittently. Thanks again for the great instructions and pictures.

 

Well, the update on my no start and battery drainage involving my Relay Control Module is that I mailed it to Tighed1 and he resoldered it etc and it is going on one month and all is good. I have no trouble codes and I have not had the failed starts at stop lights nor any drainage of the battery. I am now in a good place.

 

2004 cranking but would not turn over i.e. run. RCM was fixed last month so not sure what's up. Went out to grab dinner engine started and stopped ok no problem. Symptoms: Turn key ignition starter cranks several times but engine won't turnover and then let sit 20 minutes and it started, then pulled into garage and now Check Engine Light is on? Ideas welcome.

 

99.9% chance you now need a new BOSCH BRAND crank positioning sensor.. "click" on the red text below.. CPS Replacement..