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I have been having a small problem with my drivers door switch not being able to lock or unlock the doors. The remote works fine and the locks engage when the car is put into drive. I replaced the entire switch assembly and it had no effect. I finally got my Techstream back up and sure enough there is an error code of B1221 stored. The description is Power window master switch circuit. I have learned to live with it so it hasn't been a big problem. However, if anyone knows anything about this I would appreciate the advice. Again, the entire switch assembly has been changed and that did not solve the problem.
Are you referring to the lock switch in the door in the cab? If so, (not meaning to state the obvious but...) it is likely either a switch with dirty contacts or something with the ECU that controls the lock (and I'm guessing the windows). However, I wouldn't expect a dirty or bad switch to cause an error code. The error code would point towards a problem with the ECU's switch sensing circuitry.
Are you referring to the lock switch in the door in the cab? If so, (not meaning to state the obvious but...) it is likely either a switch with dirty contacts or something with the ECU that controls the lock (and I'm guessing the windows). However, I wouldn't expect a dirty or bad switch to cause an error code. The error code would point towards a problem with the ECU's switch sensing circuitry.
Yes, the switch in the door. I have seen that some cars have something called a power window control module that controls the functions of the switches in the doors. I can't find anything like that for the SC.
That code is for the window according to the attached pic....b1222 would be for the lock.
just curious, does it matter if the car has been in the hot sun or not?
are you 100% it is not the door lock actuator?
has it ever been changed?
what year and how many miles?
door lock actuators are a common failure item.
i will break out the wiring diagram and service manuals shortly.
Are you referring to the lock switch in the door in the cab? If so, (not meaning to state the obvious but...) it is likely either a switch with dirty contacts or something with the ECU that controls the lock (and I'm guessing the windows). However, I wouldn't expect a dirty or bad switch to cause an error code. The error code would point towards a problem with the ECU's switch sensing circuitry.
I agree Harold, it sounds like the drivers door ECU...but he did say he replaced the entire switch assembly...
since he has Techstream, it’s time to use the diagnostic software in TechStream.
iolmaster, can you lock and unlock the door with TechStream?
I just read each door ECU controls the lock in each door...since both doors won’t lock with the physical drivers door switch it must be something else.
BTW, try to lock the doors by doing the following.
Get in the car and close both doors.
start the engine, leave in Park
try to lock/unlock the doors.
That code is for the window according to the attached pic....b1222 would be for the lock.
just curious, does it matter if the car has been in the hot sun or not?
are you 100% it is not the door lock actuator?
has it ever been changed?
what year and how many miles?
door lock actuators are a common failure item.
i will break out the wiring diagram and service manuals shortly.
No difference if in the sun or not. I am sure it is not the actuator itself. Both doors work just as designed. I can lock and unlock from the key and the doors lock and unlock when put into drive and park. Both doors can be locked an unlocked from the passenger door. I can lock and unlock from Techstream so I think it is unlikely the ECU. I did put a new door switch assembly in when it first started and it did not correct the problem. So, it is unlikely the switch itself. It could be a loose connection in the plug or a broken wire in the bundle going through the door hinge. I have had that type of problem with wire bundles going to a rear liftgate on SUVs. The other switches in the door work fine. Windows and window lock button. The only problem is with the driver's door lock switch. The only other symptom is when you open the driver's door you hear a clunk like the actuators trying to engage. This is both getting into and getting out of the car. However, the actuators do not lock the car. It just makes a noise. Also, with the car in Park you cannot lock or unlock the doors with or with out the car running.
No difference if in the sun or not. I am sure it is not the actuator itself. Both doors work just as designed.
I can lock and unlock from the key and the doors lock and unlock when put into drive and park.
Both doors can be locked an unlocked from the passenger door. I can lock and unlock from Techstream so I think it is unlikely the ECU.
I did put a new door switch assembly in when it first started and it did not correct the problem. So, it is unlikely the switch itself.
It could be a loose connection in the plug or a broken wire in the bundle going through the door hinge. I have had that type of problem with wire bundles going to a rear liftgate on SUVs.
The other switches in the door work fine. Windows and window lock button. The only problem is with the driver's door lock switch.
The only other symptom is when you open the driver's door you hear a clunk like the actuators trying to engage. This is both getting into and getting out of the car. However, the actuators do not lock the car. It just makes a noise.
Also, with the car in Park you cannot lock or unlock the doors with or with out the car running.
Okay, so the physical switch has been replaced, not the ECU. You can lock and unlock the door with Techstream or the passenger door, just not the driver's door lock switch. So I'm guessing that would narrow it down to a couple of things:
Just as you suggested, it could be a wiring problem. A wire could have broken between the switch and the ECU. (IMHO, this is the least likely scenario since there shouldn't be any movement of this wiring harness other than from any work done on the door. Maybe a little shock from slamming the door closed.) Or a pin could have backed out of one of the connectors or corroded/gotten dirty. (For this bullet point, this is the most likely scenario for a bad connection.) Both of these can be checked with visual checking and an Ohm meter. The problem with testing the broken wire is that you may have to wiggle the wire around in order for it to break connection, as in certain positions it may reconnect.
The second likely cause would be the ECU. If the "sensing circuitry" has gone bad for that switch, the ECU will not recognize this switch but will still work with the other sources (Techstream and the other door controls). By "sensing circuitry", I mean the circuitry that the ECU uses to monitor the switch closure with. (I know that you, iolmaster, already understand this but this may help someone in the future who isn't as electrical savvy as you.)
If it were me, I would check the yellow wire I highlighted in the pic below.
it is common to both lock and unlock and unique from all other controls.
agree with Harold about checking the pins for a solid connection and possible corrosion.
always fun taking the door panel off...
Okay, so the physical switch has been replaced, not the ECU. You can lock and unlock the door with Techstream or the passenger door, just not the driver's door lock switch. So I'm guessing that would narrow it down to a couple of things:
Just as you suggested, it could be a wiring problem. A wire could have broken between the switch and the ECU. (IMHO, this is the least likely scenario since there shouldn't be any movement of this wiring harness other than from any work done on the door. Maybe a little shock from slamming the door closed.) Or a pin could have backed out of one of the connectors or corroded/gotten dirty. (For this bullet point, this is the most likely scenario for a bad connection.) Both of these can be checked with visual checking and an Ohm meter. The problem with testing the broken wire is that you may have to wiggle the wire around in order for it to break connection, as in certain positions it may reconnect.
The second likely cause would be the ECU. If the "sensing circuitry" has gone bad for that switch, the ECU will not recognize this switch but will still work with the other sources (Techstream and the other door controls). By "sensing circuitry", I mean the circuitry that the ECU uses to monitor the switch closure with. (I know that you, iolmaster, already understand this but this may help someone in the future who isn't as electrical savvy as you.)
So that is my 2¢ worth. Hope that helps.
One thing I have not been able to determine is, where the ECU is for this function. Is it in the door? Once it warms up a little (we are having an ice storm right now) I will remove the switch assembly and check all the connections at the plug with my trusty Radio Shack volt/ohm meter. The schematics provided by BGW are a big help. Thanks!
If it were me, I would check the yellow wire I highlighted in the pic below.
it is common to both lock and unlock and unique from all other controls.
agree with Harold about checking the pins for a solid connection and possible corrosion.
always fun taking the door panel off...
I saw that yellow was common to the switch. Great place to start. I will check the connection at the plug first. Again, thanks
Good suggestion BGW. The schematics are definitely a help.
iolmaster, this picture is not very good but if you look just to the right and below the speaker at the top right, you'll see a small black box with an L on it. I believe that is the ECU but I'm not 100% sure. Sorry that I don't have a better picture of it though. (The picture was intended for window adjustment, so ignore the pointing fingers.)
02-11-21 | 11:15 AM
Dtc b1221?
