Yay! After cleaning a few more grounds all but the 1 TCS code have vanished.

Now to try and check the voltage on the damn steering sensor with out blowing the air bag in my face

 

I am having this issue as well, has anyone narrowed down what could be causing it? I have replaced the battery with a red top optima, checked the grounds below, but don't know where to go from there. The fuel pump is not priming when I turn the key to "on". Is it possible that the oil level sensor is bad and causing the ECU to not start the pump?

Grounds checked:
G101
G102
G103
G104
G104
G106
G107
G401

Thanks in advance,

Brad Skinner

 

thank you so much for your help on my grounding problem. it was a dirty end on one of the ground plugs #106, it was making my dash lights blink real fast. and my turn signal not to work. again thank,s for your help (george)

 

I have had the fuel sensor problem corrected on my 98 when GM had the recall!
Now years later I'm getting emty fuel reading and check the gages.
I reset, stop the car, after a minute restart and everything is okay for a while.
I will be putting techron in my tank tommorrow.

 

My 01 instrament cluster just drop out when driving and the code in the bcm is u1096 any reccomendations?

 

Un-plugged and re-plugged the connector going to the EBTCM (above the rear axle) and cleaned the nearest gound..

No more codes!

 

need help bad. had the dreaded service trac and engine died but waited few minuets everything was fine. all the codes were history codes. car seemed fine so i cleaned almost all the grounds and replaced the battery. car was running ok. today went for short ride and when i was stopped at a light i saw the volts start to jump from 11 to normal 13.4. got home and found out that sitting at idle if i stepped on the brakes there would be an interuption like the electrical died just a split second but the driving lights were rapidly blinking and the dash lights like there was spikes and lows like shorts happening. im sorry this is so long dont know were to start please help.

 

I've cleaned 9 of the 13 GND points, and all looked pretty good. Zero corrosion so far....just tranished. However i can't find the last four GND locations: 201, 202, 301, and 302? Anyone know exactly where these are and how to access them?

Thanks!

 

Those four are in the cabin. Remove the plastic cover that encloses the seat belt retractors and 301 & 302 ARE BEHIND IT. One one the left and one on the right.

201 &202 ARE UNDER THE SILL PLATE COVER. Remove it and look here:





BC

 

Ahhh....no wonder i couldn't locate them, I was thinking all GND points were external.

Thanks for the info Bill!!!

 

What is the type of grease I should use/How much should I use and what should I use to do the actual cleaning?

 

I will post what seems to have fixed the problem; I went out and bought a used BMW 328i last Saturday as a daily driver to give me time to troubleshoot the z06's issues, and the next morning the z fired right up and has every time since. I don't know if the car model has to be BMW to solve this problem, but that is apparently what worked for me.

Brad

 

Just wanted to pass a long a very greatful thank you. I, like so many others who are on this forum, have experienced the problems related to the TC/AH/ABS warning light problems. I want to compliment you on this particular posting because it enabled me to correct the problem on my recently purchased, used 2002 C5 Convertible. I was getting the infamous C1214 code and immediately thought I was about to spend mega-bucks to have it repaired. I started doing some research and ended up finding this posting and to my delight, followed your instructions to the letter and I think my problem is cured. I got home from work this afternoon and began the procedure to clean my ground terminals. I was very surprised to find them in such a poor state considering the car only has 21K miles on it and has been in bad weather only a few times in its life and is parked in the garage most of the time. It would seem that this procedure should be included as routine maintenance. Any way, I have driven the car most of the evening and have checked the ABS by braking hard from about 40 MPH and the ABS kicked in just as it was suppose to. I did this twice and no lights have come on and no additional DTC codes have been added to the list. I thinking that is safe to assume at this point that the problem is cured. Again thanks Hoby

 

Had same problem. starts off with sticking lights not opening once in a while. You open the hood and turn the headlight motor **** and release the tension so to speak and then cycle the light switch and it opens up.
You then start hearing the dreaded 5 second loud clicking, which is just telling you the teeth on your headlight gear has some broken teeth and is about to not start opening at all. The gear is plastic and eventually strip.
I just replaced both of mine with the CNC brass gear and have heard they should last forever. Certainly much, much longer and stronger than those cheap gears. Drivers side took me about 45 minutes to do including reinstalling the headlight and testing. It took me about 15 minutes to do the passenger side once I knew what I was doing. Recommend doing this fix yourself. Each gear is about $40 but will never have to change again and the labor was free and done right, by me, and there is no one more careful at doing it right and not scratching my paint than myself.

 

Mine does the same thing. I will be checking my grounds this weekend. Thanks for the post!!!

 

I have the same code problems as you. Do I need to clean only the two in the engine compartment? If I need to clean more, where exactly are they?

 

I have the reduced power problem ansd was told to get a new throttle control module. Do I need to clean only the grounds in the engine compartment? If more are needed, where are they exactly? Cindy

 

engine ground strap top left frame behind left front wheel well

G101 left front frame (with SP101)
G102 right front frame (with SP100)
G103 left front of engine
G104 frame next to battery (with G108 & SP102)
G105 left lower engine block, engine ground strap & wire
G106 Battery negative pole
G107 Left rear head
G108 frame next to battery (with G104)
G201 bottom of A-pillar, left (with SP201 & SP203)
G202 bottom of A-pillar, rt, bolted at the bottom (with SP202)
G205 inside door pillar driver seat (with G301)
G301 inside door pillar passenger seat
G302 inside door pillar driver seat (with G205)
G401 left rear outer frame
G402 right rear inner frame
SP201 bottom of A-pillar, left (bolted with G201)
SP202 bottom if A-pillar, rt (bolted to G202)
SP203 bottom of A-pillar, left (taped to wire bundle, with G201 coming out of it)

G101: windshield washer fluid pump
Windshield washer fluid level switch
Brake fluid switch
Headlamp door assembly, left

G102: cooling fan, right
Cooling fan 3 relay 44
Horn assembly
Underhood lamp
Headlamp door assembly, right
Headlamp door control module
A/c compressor clutch
A/c compressor clutch diode
Secondary air injection pump

G103: Electronic brake control module (ebcm)
G104: battery negative pole
Splice pack SP102:
Marker lamp, right front
Marker lamp, left front
Park/turn signal lamp, right front
Park/turn signal lamp, left front
Turn signal lamp, right front
Turn signal lamp, left front

Splice pack SP208:
Body control module (bcm)
Instrument panel cluster (ipc)
Data link connector (dlc)
Inflatable restraint & diagnosis module
Inflatable restraint ip module disable switch
Park/neutral switch
Remote control door lock receiver

G105: fuel pump relay 35
Engine oil level switch
Heater O2 sensor, bank 1 sensor 1
Heater O2 sensor, bank 1 sensor 2
Heater O2 sensor, bank 2, sensor 1
Heater O2 sensor, bank 2, sensor 2

G106: battery negative pole
Ignition relay 42
Powertrain control modules (pcm, 4 wires)
Throttle actuator control module (tac)
Mass airflow sensor (maf)

G107: ignition control modules 1-3-5-7
Ignition control modules 2-4-6-8
G108: Electronic brake control module (ebcm)
G201: Splice pack SP201:
Data link connector (dlc)
Air temperature actuator
Instrument panel cluster (ipc)
Traction/suspension control switch
Driver door module (ddm)
Door latch, driver
Auxiliary power outlet
Windshield wiper motor
Steering column lock
Footwell courtesy lamp, left
Instrument panel cluster (ipc)
Hazard switch
Telescopic actuator switch

Splice pack SP203:
Remote CD changer
Fuse block I/P
Speaker, right door
Speaker, left door
Radio

G202: Splice pack SP202:
Passenger door module (pdm)
Door latch, passenger side
Body control module (bcm)
HVAC control module
IP compartment lamp
Footwell courtesy lamp, right
Vanity mirror lamp, left
Vanity mirror lamp, right
Inside rearview mirror
Bose relay 45
Ignition switch
Blower motor relay c60
Blower motor control processor
Hood ajar switch
Cigar lighter
A/t shift lock control solenoid

G205: seat belt switch, driver
Seat control module (scm), driver
Seat pump, driver
Seat belt switch, driver
Seat relay center, driver

G301: defogger grid
G302: Splice pack SP302:
Seat relay center, passenger
Seat pump, passenger
Rear compartment courtesy lamp, right
Rear compartment courtesy lamp, left
Rear compartment lid latch
Rear compartment lid latch, right
Rear compartment lid latch, left
Folding top lid latch
Folding top release switch
Fuel door lock actuator
Radio power antenna

G401: Splice pack SP400:
Fuel pump & sender assembly, left
Fuel level sender, right
Tail, stop, turn signal, rear left
Tail, stop, turn signal, rear right
Center high mounted stop lamp
Backup lamp, right
Backup lamp, left
License lamp, right rear
License lamp, left rear
Marker lamp, left rear
Marker lamp, right rear

G402 electronic suspension control module (esc)
_

 

Cindy

Its EXCELLENT to see a female doing her own work!

I see you ave a 98. There was a Technical Service Bulletin that discussed the TAC Module problems that 97 and early to mid year C5 had. Some in-fact did have a defective TAC module. Mine was an early 98 and suffered BADLY from repeated and frequent bouts of Reduced Power (RP) fits!

Your very first course of action is to read the DTC's that are present when the engine is in RP. Some times just clearing the DTC will get you going again. I was so good at it, I could do it on the fly and never even slow down. The DTCs will tell you if you have a BAD TAC or some other TAC system component.

Changing the module your self is very easy and it is a plug and play install. Its the BLACK box on the outside of the PCM in this picture:

<img src="http://img.photobucket.com/albums/v402/bill327/C5PCMandTAC2.jpg">

<img src="http://img.photobucket.com/albums/v402/bill327/C5PCMandTAC3.jpg">

You access the module from the fender well access in the passengers front fender well.



The module cost $230ish and the best deal can be had from Gene Culley at gmpartshouse.com

There are other things that can cause this issue but,,, like I said, 97 and early 98's should have the module changed.

Grounds do not cause this issue because the TAC circuity is a discrete circuit and only connects to the PCM, TAC module, Throttle position Switch and accelerator pedal position switch.

Having an early C5 you should suspect the grounds anytime there is an electrical issue. Knowing where they are and how to service them is the first step in basic FREE repairs. The grounds in the engine compartment seem to get corroded faster than most of the other ones. G101,102, and 104 are most corrosion problematic. G-401 and G402 (if you have a rear DTC and lets see what pans out.

 

Ok, I just lost the FOG lights on my '99. I've already verified that the ground to them is no longer connected. Power is being fed to them properly. My manuals are lost somewhere in my tiny garage or buried in there. I need to located which splice pack is their ground source and where that splice pact is located. I believe it is the one on the right top frame rail near the hood mounting but in a wiring CD that I have for the car, it says a splice pack somewhere hidden in the right wheel well and I know for a fact, the data on this CD is questionable as in not always right.