ericlouie1

The p0500 was set on dry asphault, with no wheelspin, hard braking, or hooliganism. Just thought I would give an update to this, I got a phone call from circuitboardmedics on thursay, notifying me that the module was shipping back to me. The guy on the phone wasn't a technician, he just explained that they found something wrong with it that they typically don't see. It also took a bit of time to trigger the faqult on their test bench. I received the abs module back saturday, plugged it in, and voila, no lights, speedo is back, and odometer works again. Put about 130 miles on it between then and now, and all seems good.

Module was sent back last friday, I'll keep updating as I go along.

All of the sensor ohms were read full loop, from the connector to the sensors. All of this testing was performed with the truck sitting, not even driving it. Before I sent the module out I had the internal relay code, the fuse pulled, had the brake light on, but still had a speedo. Now I have no speedo, CEL's, but no brake light....confusing. I want to get the module interface issues sorted out before I start messing with the drivability end of it. No o-scope is available to me right now anyways, so its a moot point currently. Although I do have a analog simpson meter that I might be able to use for that particular test.

I was able to intermittantly communicate with the abs module with a snap on solus, until the air bag light lit, odometer dropped out, and the CEL came on. Voltages at abs connector(disconnected) seem fine, 12V for all fused inputs, 2.5V for CCD bus, and 5V for the speed signal reference. This is what I have done so far. I pulled all of the ECU, PCM and ground connectors under the hood and checked for corrosion and gave them a light coat of dielectric. Removed grounds from frame, battery to body, random one at rad support, one at d/s firewall going into the cab, pcm to body, sanded paint off of body/frame, cleaned ring terminal, new screws, and a small coat of grease. All points between grounds is about .3 ohms. Contact cleaned the connectors going into the abs module, and tried them dry, really didn't make any difference, the longest I can communicate with the module is for about 3 minutes. During this time, I am able to look at the data display, activate the pump through the scan tool, and look at any codes(none present) I can re-establish communication after about 5 minutes of sitting and clearing the CEL, or by disconnecting the ABS module, then reconnecting. I did determine that at least one of the batteries is bad, there was resistance between the negative terminal and body ground of about 5 ohms. This would climb to around 20 ohms when a door was opened. Put a brand new battery in and the resistance dropped to 2 ohms, climbing to 8 ohms when the door is opened. Thats a strange one for sure. With the abs module disconnected, no CEL, or other errors occur. This sure is an interesting one. BTW, CEL's thrown are P1693 and P1698, not much info there though.

Drove it this morning to work, speedo lasted about 5 minutes before airbag light came, dash did the goofy dance, and lost the speedo.....but no brake light, just a CEL and a lack of speedo.

Yeah, once the abs module is unhooked the brake light goes out, as does the "bus" errors/check engine light, but no speedo. I am thinking that the abs light in this truck is burned out, as I do not ever recall seeing it turned on.

So after disconnecting everything, light cleaning, regreasing i pulled the truck out of the shop...no lights, speedo seems to be working...start driving up the street and I get to about 15 mph, airbag light comes on, speedo drops out, check engine light comes back on, and so does the brake light. Back to square 1.

Yeah, I jsut cleaned all the connectors the best i could(no contact cleaner with me) and re-greased them with fresh dielectric. Going to go out now and see if it made a difference. Worst comes to worse I'll unplug all the abs stuff and just stick a portable GPS unit in front of my speedo....stupid chrysler and their stupid technology. LOL!

My big question is that before I sent the module out I had a speedo, but the brake light was on, after I got it back, now I have no speedo, and still have the brake light on....it got worse!

I was getting the abs module open relay code, so I sent the ABS module out to circiutboardmedics to have it "rebuilt"(not 100% sure what this service entailed)Anyways, before I sent the module out, I had a constantly lit brake light, as well as a working speedo.I received the module today, and thinking everything was honkeydorey, plugged it in, all was well for about 1 minute, then the gauges temporarily died, I got the check engine light and brake light(p0500, p1693 and p1694 codes when pulled with the 3xkey trick)The rest of the gauges came immediatly back, except for the speedo.The driver side wheelhub was just replaced with a new skf unit and sensor. The p/s hub and sensor looks like it was replaced before i purchased the truck.ABS fuse in cab is good, and 40A fuse in engine bay looks good as well.I checked the resistance of all the wheel sensors, as well as a check to ground for each wire, no continuity to ground on any of the sensors.The resistances from plug at ABS module to sensor looks like this-D/S front sensor 1.03k ohmP/S front sensor 1.06k ohmRear wheel sensor 1.7K ohm I also checked voltages from the plug to ground, but they seem kind of pointless, considering I don't have a schematic/pinout of the plug handy.Anyone have any input on this one, I'm going to contact the vendor in the AM to see what they say. The truck in question is a 2001 RCLB 4x4 HO 5.9 6 speed 103,000 on the odometer