I have something strange here. I cannot unbolt the ground points in my car because another part "touches" them and prevents me from placing my wrench. I was wondering why there is this part ... It looks strange too me.

I have the same thing in the two ground points I have checked: next to the coolant liquid and the washers liquid.

 

WOW-just what I was looking for--My C4 has been quitting at odd times-Totally dead !!-When running lights,instrument panel,etc flickers-After new battery,etc--no change-I felt sure it was a ground problem,as I had the same trouble with a Suburban(supercharged sleeper-Yee-ha !)that was finally traced to engine ground.Obviously a little harder to locate all on C4 ! I'll report back after checking all.
Thanks, Randall(kg4tiw)

 

Great !! Thanks !

 

Bill,

First like many here I thank you for being here and all the help that you are giving.

I have 01 with no engine mods. I recently replaced my battery and show to have good voltage using a meter. I am getting only one code which is C1232H. I have cleared the code numerous times, however when I accelerate to around 35 to 45 mph I get the service ABS and traction control message. I pulled the wheel and checked the connectors going to the hub and cleaned and applied dielectric grease. I still get the error code. I have checked the grounds at G101 and G102 and they looked good with no apparent problems. Am I missing something?
A buddy of mine says to have the ABS module repaired by ABSfixer but I am (my wife says cheap) thrifty. However I want to get this fixed and will spend the money if that's what it takes.

Thanks for any ideas you may have,

Jim

 

Hey Jim,
This is the code you're getting, yes?

C1232 LF Wheel Speed Circuit Open or Shorted

I'm no expert, here, just a little of my personal experience to offer; but my issues required a new ABS module. That said, we found numerous bad connections and corroded grounds along the way.

My 01 blew several different codes and was very inconsistent. So, I don't know if the module was bad up front or resulted from the connector and ground issues.

In the end I spent untold hours troubleshooting and thousands of dollars getting it fixed. Money spent was across two dealerships and finally a local Corvette engine builder/tuner that actually fixed the problems.

Partner, I hope you find your problems faster and cheaper than I did mine!

- Terry

 

Terry,

Thanks for your reply. I have checked the connections and the main grounds at the front and all looks OK. I only have 40,000 miles on my Vette and I know that really doesn't mean much with electronics. I just about ready to pull the ABS module and send it for repair.

Thanks again,

Jim

 

Your issue CAN NOT be fixed by the ABS Fixers..
You have an issue with the connections between the wheel hub connector and the connection on the K member sub frame. Additionally, adding dielectric compound inside the connectors can contribute to the problem. Dielectric compound is non conductive and if the connection between the male and female pins in the circuit is anything but perfect, the dielectric grease can prevent the connection form taking place. The voltage that the wheel speed sensor circuit works on are in the millivolt range at low speeds and five volts at higher speeds. The output voltage is also an AC voltage.

You need to remove the JUMPER HARNESS and inspect the female pins on the frame connector and in the jumper harness.

I insert a spare male pin into the female pins in the connector. If there isn't a tight fit, the female pin is bad and needs to be repaired or replaced.

If you indeed have inspected the female pins in BOTH connectors and they do make correct connection with the male pin, you most likely have a wire harness issue. Look for damaged or broken wires.

The wheel speed sensor circuits do NOT depend on chassis grounds for operation. The circuit is a discrete circuit and uses a signal wire and a low reference or return wire.

If you had NO EBTCM operation then chassis ground could be an issue as the module uses chassis ground for 12 VDC power return.

You can measure the output of the wheel speed sensor by using a AC Volt meter on a scale that will read 0-5 VAC. Turing the wheel by hand will get you a millivolt output.

Hope this helps.

BC

 

Bill,

I have pulled the jumper and checked the pins again. But I'm going to try and find some flat male pins so that I can do a better check on the female connectors. I may just see if i can buy a new jumper. I'm going to Dallas next week, I live about 150 miles away, surely I can find the flat pins or the jumper somewhere in Dallas.

Thanks for your help,

Jim

 

NAPA carries a good selection of pins. Most dealerships also carry a connector repair pack with the male pins that you need. The male test pin doesn't have to be the exact same pin. Just the same male pin thickness and width. You can try Autozone and advance auto also. The Advance here carries most of the common connectors and can get all the others thru a catalogue..

I busted up an old emergency flasher module and saved the male pins. They are my test pins.



Nothing elaborate but it works for the purpose of proving or disproving female pins.

BC

 

Thanks again Bill,
We have a NAPA and Auto Zone. I will check them today.

Jim

 

Bill sent you an email earlier today. Yeah.......that whole dialectic grease thing may be something I will look into and clean those grounds up asap. If there's anything else I can try to do other than replacing my brake switch as stated please let me now.
Again - thanks a bunch for all of this direction!

 

I switched the right jumper harness to the left side. Still got the dash lights, and DIC message "service ABS and traction control" and the C1232H code. I checked the pins again. Then I tried checking the hub and I got voltage at the connector while spinning the rotor. I can't see any wires that look frayed or loose. I'm old and it's already 90 degrees outside, I'm done for today. Not sure where to go next.

 

I found some pins but they were not exactly the same, so I went to a wrecking yard and the guy let me cut an exact connector off a car. I took the pins out of the connector and they are the exact same pins. Try a wrecking yard if you can't find them.

 

Yeah, anyone know what those big nuts are securing on each frame rail?

 

That is ONE of the bolts that secures the front K member (cradle ) to the cars frame. The broken RIVET that you see should secure that tab to the lower tab so the bolt stays captured and doesn't spin when its removed or reinstalled. You can loosen the bolt from under the car and spin that tab back around or,, just bend it out of the way.



BC

 

Bill, I'm getting these messages in the DIC:

Service Active Handling
Service ABS
Service Traction Control

The three messages can be made to disappear with the reset button but will all reappear again later. The warning lights on the dash stay lit of course.

Checking for codes reports the following:

C1282HC Yaw Rate Sensor Bias Circuit Malfunction

C1284HC Lateral Accelerometer Sensor- Self Test Fault

C1285HC Lateral Accelerometer Sensor Circuit Malfunction

C1287HC Steering Sensor Rate Malfunction

C1288HC Steering Wheel Position Sensor

C1296HC Master Cylinder Brake Pressure Sensor Circuit Open Or Shorted

Additionally there were two other TCS codes stored:

C1233H RF Wheel Speed Circuit Open or Shorted

C1237H High System Supply Voltage

I have had some battery and battery charging issues (Battery Tender malfunctioned and boiled one of the batteries down low on water, one cell nearly all the way, prolly the bad one?) New battery now and new BT.

Manual says relay may have switched off these circuits when it sensed over voltage and will have to be reset with a Tech 2 or I can wait 100 ignition cycles and the EBCM will do that if it does not detect a recurrence. Am I on the right track before I start checking and cleaning all the grounds? 04 with 2K miles.

Thanx, Greg

 

Greg

RESET ALL of those DTCs using the reset button and then see what comes back when you drive the car again.

Bill

 

Thanks for the reply Bill. Reset is only temporary, DIS Displays the three messages again and again within a few miles after each reset.

Greg

 

Tested again after reset and test drive. Service Traction Control, Active Handling and ABS messages reappeared in the DIC after a few miles but only codes showing now are :

C1233H and C1283H

Thanks in advance,
Greg

 

Agreed. It makes no sense at all to have a plug there.