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Please help with codes C1200 and C1504

51K views 13 replies 4 participants last post by  qsaghar  
#1 ·
After exhausting the brake light switch avenue, I need help with these two codes.

Summary of work thus far.
My ABS/BAS/ESP lights came on as I was cruising down the highway. Sunny day, no braking involved. Just out of no where. Cruise control works. All brake lights and turn signals work.

Replaced brake light switch twice with units from the dealer, hoping the first one was defective. Adjusted BLS plunger to every single depth (no joke).
Replaced battery with brand new one, since the start up voltage was below 11V.
Alternator checks fine.
Codes read from Aamco by unknown machine.
Codes are C1200: Stop Light Switch Open/Shorted/Implausible
C1504: BAS light, play in steering column causes steering angle sensor to lose memory
No other codes are thrown.
The five wires leading into the BLS look brand new. I did not see any breaks in the wires.
Every single fuse in car is good, under the hood, under the backseat and by the driver door.
With steel wool, I cleaned the connection of the negative jumper to the car chassis as well as the metal where the jumper would connect.

Thank you in advance.
 
#4 ·
I have never dealt with these particular codes.
From what the WIS says the error is most likely being caused by an inoperative yaw sensor in the steering column.
Suggestions include resetting the yaw sensor. Checking the harness and then replacing (its expensive).
The yaw sensor error will set a brake code too.
I'll keep looking
Cheers
Barri
 
#5 ·
A bit more digging and I found
Which is evidently very like ours on the e320. Part seems to cost between $200 and $300. Get some more opions before you change it. There are lots of threads on steering angle sensor - particularly in the c and ml class cars.
Cheers
Barri
 
#11 · (Edited)
Hi SkippyJasper. Thanks for joining the discussion. I laid out the fixes I tried in the first post. Other than that. The car has been pretty problem free. I bought it 3 years ago with around 100k on it. It now has 160k. I replaced the water pump last summer. Straight forward. I change the oil regularly myself. Maybe the easiest oil change ever. No other mechanical issues.

There is a little play in the steering wheel, but nothing obscene. But how sensitive are the MB sensors? I saw how to disassemble the steering column and feel pretty comfortable with that, if I need to replace the steering angle sensor. What else could cause the failure in the play of the steering wheel? I had a full alignment on the tires less than 8 months ago. The car drives straight as an arrow when letting go of the steering wheel on a straight road.

Thank you for any help!
 
#13 ·
On top of skippy's excellent suggestions (which is what I would check first) - did whoever did the alignment realign the shaft/wheel when they had finished (i.e do both front wheel adjustments so the column remained centered) if you have just a mm or 2 misalignment in the column and a mm or 2 of play then on stop to stop turns the sensor gets thrown out as it is seeing less turns one side to the other. That will be enough to throw a code and yes they are sensitive.
cheers
Barri