Check AZ or Advance or Pepboys.

 

Hey Bill....I've been scanning thru all these posts about cleaning the chassis grounds..like in your very first post. I want to do mine under the hood after Xmas. Question...do I unhook the neg. battery cable first before messing with any of the grounds?? I didn't see that stated anywhere, but may have missed it.

Thanks,
Dennis

 

Yes,,,it a good practice to disconnect the NEG batery terminal prior to ground maintenance.

BC

 

I'm checking all of these connections in the morning

 

Bill,

I have had an issue with my '98 Rear Mount EBTCM with a "NO COMM" signal on the DIC with the ABS and Traction Control ICONS lighting up on the dash!

Now, what I had done in the past was unplug the Wire harness going to the module, plug it back in, and it would be fine "UNTIL" I hit a hard bump in the road and then bamm back on - go home and repeat Unpluging and Pluging back in of the harness!

I thought the harness Clip was backing out or it needed to be snugged up so I put a small cinch strap on the handle to apply a little more pressure to the clip - WOW! all seemed real good and then one day bamm back on after I went over some railroad tracks! Did above procedure again and all is good!

I thought it might be the ABS/TC Module, So I picked up a low mile used one from a member and slapped it on and it was good and good for a while - I thought problem solved, it must have been the Module (The previous one had been on there for 92,000 miles and had a problem once, it had a bad solder joint taht was fixed - "BUT" it never had a "NO COMM" on the DIC) then just the other day it happened again

When I replaced the Module I checked all the pins in the new one and the old one and they were perfect, in the wire harness Clip I check to see if the female part was open too much (Not making enough of a pinching connection) and after inspection it looked good from my perspective, although I will check the female end of the harness again just too make sure!

My Conclusion:
I believe it is in the female Harness Clip and the ground (My question is about the GROUND), because it will always be good after I remove it and put it back together! I have not checked the ground going to the unit - YET!

Anyway I have my Helms manual at home, but not here at work, Which leads me to my question:

1. On our 1998 Rear Mounted ABS/TCM how many grounds do we have going to it? Which side of the Vette does it go to? ( I believe the drivers side rear )

2. Is there a Ground in the Clip as well as the one on the ABS motor or is it "ONLY" the one Ground on the motor?

3. If it is not the Ground Wire, Which one of the wires in the harness could be making it loose COMMUNICATION with the BCM/PCM?

4. Do you happen to have a wire schematic handy showing the wiring diagram you could shoot me here at work? and the Helms page number for quick refference I will check it at home but due to the rain I have some time to kill @ work

I PM'd you too Just in case!

I can call as well, if I could

Thanks,Matt Cell 661-406-7516

 

Bill these pics help big time So I brought them up right under my post for quick reference!

Thanks,matt

 

Here in SoCali its been raining for DAYS! guess what popped its ugly head in my 99 Vette? Electrical GREMLINS LOL

driver side controls (mirrors, windows and locks) stopped working and illuminating...next up...REDUCED ENGINE POWER gauges all go flat bongs and dings...

The car is currently in the garage with its tail between its fat rear! Who knew the first rainstorm in Cali this year would one up the Vette, my daily driver of nearly 4 relatively problem free years.

I finished cleaning all the front end chassis grounds and the two kick panels, BTW I will get to the harness in between the door hinge of both sides, I hope that solves it! I wouldn't want to take it outside today anyways since its still pouring down here in "Sunny Southern California" I will keep you guys posted

Thanks BILL!

 

I bet you a nice sunny warm day that your problem is most likely a wetted BCM. Check the passengers foot well and the BCM for water/dampness. Move the seat all the way forward and pull up the carpet and feel the underlayment and see if it is damp.

If it is...Let me know.

BC

 

Hi Bill,

Can't thank you enough for the wealth of information you provide this great community. I hope to one day be as fractionally knowledgeable as you are

Anyway I cleaned all grounds forward of the two kick panels since it was hard for me to do the rears in my tight spaced garage (couldn't pull the car out because of the rain) floors/carpeting were dry thank god so BCM is out of the question at this point...so I finally take the car out for a drive and the same thing happens "Reduced Engine Power" warning lights etc. But strangely the warning messages started right after the driver control panel went out again. So as i pulled back into the garage i fiddled with the rubber boot that protects the wiring in from the door to the dash without even completely removing it ( i just pressed my fingers against the rubber boot in an attempt to free up any tangled or crimped wiring ) it's been two days problem free so far

 

Hi Bill

The original alarm system on my C5 -01 is not working as it should.

When I lock the car with the FOB only the front turn signals flashes one time and not the backup lamps, and there is no flash at all on any exterior light when I unlock the car.

And if I set of the alarm the horn is pulsing but none of the exterior lights flashes, only the lamps that is located in the rear-view mirror flashes.

I have the settings LOCK & ARM - LIGHTS ONLY and ALARM HORN & LIGHTS in the DIC display.
I have no fault codes in the DIC dispaly

The backup lights and all other exterior lights works except when the alarm wants to control them.

Any suggestions on what to do, or is does it sound like I have to replace the BCM?

Maybe take a look inside the BCM and look for bad solder points?

 

Good Morning,

I am a new member to Corvette Forum, what a great information resource from a great goup of corvette fans! I have a Blk/Blk 98 Coupe, that is loaded with options, I ordered in early 98 and took delivery in Aug of 98. The car currently has 19,000 miles on the clock, always garage kept and never driven in the rain. I started having a probelm about 2 years ago getting the codes C1241 Magansteer Malfunction and C1255 EBTCM Internal Malfunction, and the message Service ABS/Traction Control. This seem to happen every time I would washed the car at the self service car wash. I took it to the local Chevy Dealer and they replaced the EBTCM and a wheel speed sensor. It cost over $900.00 to get this unit replaced and the sames Codes came back, about a year later. I went ahead purchased new in the box EBTCM from the Parts Lady on E-Bay for $325.00. Before I installing the new EBTCM, I jacked the car up and disconected all the wheel speed sensors and coated them with Dielectric Silcone Grease, connected them back up, cleared the codes. I did this back in August of 2009, and these codes have not appeared again.

I have not installed the new EBTCM I Purchased from the Parts Lady, because the codes C1241 Magansteer Malfunction and C1255 EBTCM Internal Malfunction, and the message Service ABS/Traction Control have not returned.

This was several months ago. I wonder now if I even needed the new EBTCM that the Dealer Installed?

I recently took the car down to the self service car wash to rinse the dust off of it and I am now getting some new codes

10-PCM P1571 HC ASR Desired Torque
28-TSC NO COMM
38-RTD C1780 HC Loss of Steering Position Signal
60-IPC U1040 HC Loss of COMM with TCS

Along with these codes I am also getting the messages Service Ride Control and Service Vehicle Soon.

I looked at the front grounds and there is absoutly NO corrosion on them. This car is very clean not being out in the weather. It has an Optima Red Top Battery that is always kept on a battery tender when not being driven.

Has anyone else experienced the issues?

I hate to take the car to the Dealer, as it is very expensive to have them look at anything.

Thank You.

Jack McNabb
Mansfield, Texas

 

Okay I worked on and repaired the clip going to the ABS Module:

Removed the clip to inspect the contacts on the clip - here is what I found: By looking at the photo you can see the gap between the prongs that press on the pin in the module-





Here is what they "SHOULD" look like:





The rest looked good:



The backside of the clip w/cover removed:





I then checked ground-OHM'd it- from the Clip (Black/White striped) to the 402 Ground point in the passenger wheel well:



It OHM'd at .001 resistance :



Got my Dental Pick set out in order to pull the tabs back into place to make a tighter connection on the Module's pins:



Pulling them back into place:







Done and looks tighter and better:



I used some Electrical "CONDUCTIVE" grease to put in there for a better connection (Just make sure you are not sloppy with this so it does not cross over and cause problems) - It also inhibits corrosion:







It looks like this with the Conductive Grease in there (Just a little is good)



This is where it connects to on the Module:



Put it all back together, clipped it into the module and "IT WAS SNUGGER THAN EVER BEFORE" - then I checked the Ground From the ABS Pump to the 401 Ground Post, in the Drivers Rear Inner fender Well: OHM's out at .000







I also use a small "CINCH" strap to keep the handle down and tight in order to keep the clip in the Module (My tab on the top snapped off, due to age )





All thanks go to Bill for helping me out and getting me pointed in the right direction in order to fix this correctly - Thanks Bill

I hope this helps others too

Thanks,Matt

 

Is G104 the one that mounts on the stud beside the battery or is it up under the battery and I need to pull the battery to get to it? Is there a group splice pack associated with G104?

I have an intermittent horn and the fob doesn't. I cleaned 101, 102, 201, 202, 301, 302 and the stud mounted ground near the battery. Does 103 have anything to do with the horn circuit>

I have had the car on jack stands for three months tinkering with it putting in Frost King, replacing F45 with C6 Z06 shocks, etc.

None of the grounds had any signs of corrosion. After taking 201 apart, it occurred to me that ground might have something to do with the horn, and sure enough it blew a few times and then stopped.

Which ground do I need to service to clear up potential problems with the horn?

Charlie

 

ttt

 

I've gotten a few replys back about my electrical mystery that I caused this afternoon. Mr. Curlee can you please take a look at my post and shed some light on where I should go next.

I've read the majority of this great post/book that you've made on this thread. I've check the grounds that are about the front wheels and gave then a good cleaning. That got the car to start again. Haven't gotten to the other grounds yet due to small garage and rain storm outside, but will get to them tomorrow.

To get to my post click here.

If that doesn't work http://forums.corvetteforum.com/c5-t...eries-and.html

 

My car was in the shop for air-conditioner repair. The battery would not start the car, so they put in a new battery. When I picked up the car and still to this point am getting warning lights on ABS, Traction Control and "Service Engine Soon". I checked codes and got:
10 PCM = P1571 HC
28TCS = No Comm
58 SDM = U1040 HC.

Anybody got any clues on what to do next?

 

Replaced my original battery with a Die Hard Platinum, in doing so I heard popping coming from what sounded like under the right headlight. the ABS/ TCS and DIC trouble light showed on the dash,Codes C1283, U1000, U1064 and U1232 were all cleared except U1232 (LF wheel speed sensor circuit open or shorted) which is still there along with dash lights. Does anyone know what I may have screwed up?

 

Im sitting here in Dubai UAE 7000 miles away and I can tell you EXACTLY what the noise is.

When you disconnect the battery, the headlight motors loose power. When they loose power, they pop up a very slight amount. When you reply battery power, the headlight control module senses the lack of torque on the head light motor (thru current draw) and it attempts to pull the headlight back down.

The reason that you hear noises is,,,,,your plastic gear inside the motor drive assy is worn and its starting to slip.

If I were you,,,I would read the last part of this post and reindex that plastic gear on BOTH motor assemblies. It will give that moror drive gear another 5 -6 years or so.


http://forums.corvetteforum.com/c5-g...orialized.html

Hope this helps ya!

BC

 

Thanks for the feedback, looks like a good winter project.

Do you think changing the battery and throwing code U1232 was just a coincidence?

 

"U" Series DTCs can be a symptom of LOW Battery voltage. Clear the DTCs and monitor for future occurrences.

BC