"Advanced Trac" illuminated
Truck came in for “Advance Trac” in message center & warning light illuminated. Had quite a number of codes in the RCM & ABS modules - I can communicate w/ all system modules. Current codes were U0028-08 (Vehicle Communication Bus A) & U1A00-87 (Private communication network missing message) There were multiple history codes for the Yaw, lateral, longitudinal & roll rate sensors. Cleared the codes & the U0028-08 would return with KOEO. Scoped the communication lines @ each module (RCM, ABS & PCM) (Hi speed Wht/ blu & white wires) & the RCM, ABS & PCM all of had communication. Do I need to further analyze the can signals or next step? The only thing that stuck out was the ABS network pattern had larger ½ screen gaps in the communication packets - I don't have much experience with network patterns. Thanks.
Hello Zeb, Sorry--I have no quick answers for you. I don't know the vehicle--and it's too late to think. But I recommend this manual, by Automotive Training Group--atgtraining.com/product-catego… I'm not sure how deep you are into bus issues, up at the yard. But if it's just patterns you want, the manual has plenty. And if it's a diagnostic routine you want to get down, the…
Scope analysis of the CAN is totally unnecessary, and usually not worth the time. There are rare occasions where one can determine an issue with the bus. But, since all modules put out their own CAN messages, it is impossible to tell who's talking and who's not. A DVOM can most of the time, tell you whether the bus is shorted high or low, but the scanner would tell you what the issue is, by…
I don't work on Ford at all, but I'm getting bored between phone calls and could use some mental exercise, so I took a look at the service information. It looks like there is an additional CAN network between the ABS control unit and the RCM that transmits yaw sensor data. It's separate from the main CAN bus that also connects those two modules. I'd check RCM pin 20 to ABS bin 8, and RCM pin 19…
We sent this vehicle to the local For dealer awaiting there diagnosis…