I knew this would mess me up--C1201 (1 Viewer)

[MarkTR]

My non-straight steering wheel has been driving me crazy so I used my TechSTream to disconnect the VGRS and re-clock my steering wheel. Simple - but I was three miles down the road and the check engine light, and both VSC lights came on.

Error code is C1201 so I was sure clocking the steering wheel a few degrees must have messed up the VSC and ABS settings.

Ok-- so I pull out my TS again and performed a zero-point calibration. I first reset the memory and then used test mode to calibrate.

Followed the TS instructions and the blinking lights indicated calibration was finished.

Started her up -- the check engine light stayed lit and about four seconds later both VSC lights lit up. I assumed I needed to drive her on a straight road for a few miles.

S I took her down the road straight for about three minutes and the lights are still all lit up.

Went through the process three times-- what step am I missing using TS?


Was I supposed to clear the code first-- do not see where on TS I can do that.

 

[Malleus]

 

[MarkTR]

More info-- The CEL stays on as soon as I turn the key-- all other lights go out except the battery/AT temp red light. Start her up and the CEL stays all lights are out but in about 5 seconds the two VSC lights go on. I have driven the truck in a straight line but the CEL and the VSC lights stay on.

I do not know how to clear the codes with TS ---but after each calibration, I no longer have a code until I idle the motor for about 20 seconds- and then it shows up. But the CEL light never goes out.

I have no idea what reprogramming the zero point on the steering wheel has to do with traction control or the TC ECU.

I have gone through the steering wheel center process and the zero point for the yaw sensors and no Joy.

I looked up the static VSC data via TS and it shows zero for the yaw sensors and one with -1.


There is a window in TS that allows you to check the sensor signals- but I bailed out since I was afraid I was getting over my head.


Am I approaching this wrong? Should I have performed any other calibrations before I performed the Zero point calibration with the TS? Is my only option is to try the paper clip method?

 

[JunkCrzr89]

What engine DTC keeps popping up? The C1201 is just a generic code.

 

[MarkTR]

Thanks

All I get is the C1201 on the VSC ECU page-- but it may be on other ECU pages. like the engine ECU which I did not know should be the first ECU I should check since I know know that the CEL and the VSC lights go on no matter which ECU has an issue.

I will have to check all of the other ECU's and see if any other codes pop up. I do not have a handle on using the Tech Stream on my old Tough book which is slow slow slow - so it takes forever to connect to other ECU's. I am going to try a Health Check button and see if it will scan all of the ecus-- as seen on later versions of TS I see in videos.

I am sure if I was a wizard on TS I could track down the issue-- at the moment it is hunt and peck for me. Heck- I cannot even get the clear code icon to work- I assume it is the little motor icon on the bottom left-hand side of the TS window.

Why centering the steering wheel would affect the VSC ECU is beyond me. But the ABS light does not go on so if it is the ECU it is only one section of the board. I scanned the thread on replacing the resonators but I have no idea if this could be my issue.

I am hoping forum members can give me more things to chase down.

 

[JunkCrzr89]

the CEL and the VSC lights go on no matter which ECU has an issue.

That’s not true. The CEL only comes on for engine DTCs. On the other hand, the VSC/ATRAC lights will come on for any of the ECUs. If your CEL is on, then you have an engine DTC, and as the FSM diagnostic I posted above says, you need to resolve the engine DTC first.

Why centering the steering wheel would affect the VSC ECU is beyond me. But the ABS light does not go on so if it is the ECU it is only one section of the board. I scanned the thread on replacing the resonators but I have no idea if this could be my issue.

Stop worrying about the ABS/VSC for now - the C1201 code is generic and doesn’t necessarily mean anything is wrong with that system. Your issue lies with the engine. Fix that first.

 

[MarkTR]

That’s not true. The CEL only comes on for engine DTCs. On the other hand, the VSC/ATRAC lights will come on for any of the ECUs. If your CEL is on, then you have an engine DTC, and as the FSM diagnostic I posted above says, you need to resolve the engine DTC first.


Stop worrying about the ABS/VSC for now - the C1201 code is generic and doesn’t necessarily mean anything is wrong with that system. Your issue lies with the engine. Fix that first.

Thanks- I had not understood that the CEL only comes on when there is an engine issue-- now I understand that the VSC/ATRAC can come on anytime that there is a DTC in the system but the CEL always points to a possible engine DTC.

I had to recharge the battery in my old computer so I was not able to pull up the engine ECU and check for DTC's. I will do that this morning and update what I find.

 

[MarkTR]

Junk-- you were spot on-- pulled the engine DCT's-- and I got lucky- just the normal PO442 and PO456 codes.

I am hoping it was just my new fuel cap. The seller had put an aftermarket new fuel cap on but because it was making a honking noise when I parked the truck I replaced it with was represented as an OEM Factory fuel cap.

The OEM cap never made honking noise but perhaps honking is a good symptom. I cleared the codes and installed the old non-OEM cap and we will see. Five miles down the road and no CEL so far.


I am thinking that I should not have let my old ScanGage go with the old truck which I just sold. The scan would have displayed the codes real time and I could have cleared them as I was driving to see if they were intermittent.

Does anyone use a ScanGage on their trucks?

Thanks, Junk-

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