2000 Door Lock trouble shooting
08-28-2015, 11:37 AM
#1
Instructor
Thread Starter
2000 Door Lock trouble shooting
Recently bought a 2000. The previous owner included new outer window seals and a new drivers side touch pad saying that there had been a problem with the door locks on both sides not responding to FOB commands to remotely lock/unlock the doors.
Both touch pads for driver and passenger sides respond as they should if used directly but neither respond from the FOB. I replaced batteries in both FOBs with no results and then removed the drivers side door panel and changed out the old touch pad with the new one and still no results.
Being electronically ignorant, I'm asking if it would be possible that the lock control modules in both doors would be bad or is there a more likely culprit I should look for before assuming the problem lies with the modules/relays?
Any help appreciated.
Both touch pads for driver and passenger sides respond as they should if used directly but neither respond from the FOB. I replaced batteries in both FOBs with no results and then removed the drivers side door panel and changed out the old touch pad with the new one and still no results.
Being electronically ignorant, I'm asking if it would be possible that the lock control modules in both doors would be bad or is there a more likely culprit I should look for before assuming the problem lies with the modules/relays?
Any help appreciated.
08-28-2015, 02:02 PM
#2
Pro
Member Since: Sep 2008
Location: Tustin California
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Mine is a 2000 and I had the same problem. As everything was 15 years old, I replaced the tpms sensors, receiver, and fobs with the kit from Gene. Problem solved for me. That stuff is getting old. You may have a different problem but it sounds just like mine. Good luck, Rod
08-28-2015, 02:25 PM
#3
Instructor
Thread Starter
OK, 8VETTE7 thanks for the info. The codes for RFA are:
B1016 Loss of Communications with PCM (No State of Health message)
U1064 Loss of Communications with DCM (No State of Health Message)
U1096 Loss of Communications with IPC (No State of Health message)
Does that indicate to you any specific course of action. I also tried reprogramming the FOBs because I'd changed the batteries but the FOBs and the computers didn't want to talk. No Joy
B1016 Loss of Communications with PCM (No State of Health message)
U1064 Loss of Communications with DCM (No State of Health Message)
U1096 Loss of Communications with IPC (No State of Health message)
Does that indicate to you any specific course of action. I also tried reprogramming the FOBs because I'd changed the batteries but the FOBs and the computers didn't want to talk. No Joy
08-28-2015, 08:53 PM
#4
Instructor
Thread Starter
I think you mean U1016 and NOT B1016.
Also U1064 is loss of communications to BCM and not DCM.
As I mentioned in the first post the FOB receives encoded transmissions from both the FOB's and the TPMS. It then sends signals to the the BCM, PCM and IPC (Instrument Panel Cluster) over the serial data buss. Since the RFA has lost communications to all of these devices the use of the key FOB to lock or unlock the doors as well as your attempts to reprogram the FOB's by use of the IPC are all going to fail if the loss is permanent.
Before you start chasing the serial data buss issues, I suggest that you read the following thread about poor solder quality on the board of the FOB. It probably is the cause of the FOB failing to lock/unlock the doors. VERY common issue on the 97 - 200 FOB's. Very poor quality control by the manufacturer GM chose for the FOB's and other electronics in the C5.
http://forums.corvetteforum.com/c5-t...em-solved.html
Do the tire pressures show in the DIC? (press gauges to scroll down to Front and then Rear tire pressures) If the pressures do show then the problem is the FOB and NOT the Uxxxx codes you have. The RFA often has short bouts of communications errors even on the newer cars. You can clear those code but they are likely to come back again.
If you have a 2nd FOB you could try that as well. Otherwise the info in the link should help restore your FOB.
Also U1064 is loss of communications to BCM and not DCM.
As I mentioned in the first post the FOB receives encoded transmissions from both the FOB's and the TPMS. It then sends signals to the the BCM, PCM and IPC (Instrument Panel Cluster) over the serial data buss. Since the RFA has lost communications to all of these devices the use of the key FOB to lock or unlock the doors as well as your attempts to reprogram the FOB's by use of the IPC are all going to fail if the loss is permanent.
Before you start chasing the serial data buss issues, I suggest that you read the following thread about poor solder quality on the board of the FOB. It probably is the cause of the FOB failing to lock/unlock the doors. VERY common issue on the 97 - 200 FOB's. Very poor quality control by the manufacturer GM chose for the FOB's and other electronics in the C5.
http://forums.corvetteforum.com/c5-t...em-solved.html
Do the tire pressures show in the DIC? (press gauges to scroll down to Front and then Rear tire pressures) If the pressures do show then the problem is the FOB and NOT the Uxxxx codes you have. The RFA often has short bouts of communications errors even on the newer cars. You can clear those code but they are likely to come back again.
If you have a 2nd FOB you could try that as well. Otherwise the info in the link should help restore your FOB.
Do the tire pressures show in the DIC? (press gauges to scroll down to Front and then Rear tire pressures) If the pressures do show then the problem is the FOB and NOT the Uxxxx codes you have.
I do not have any tire pressures showing in the DIC.
I also show 6 codes in AO-LDCM:
B 2252 H
B 2202 H
B 2206 H
B 2282 H
B 2284 H
U 1064 H
There are 8 codes showing for A1-RDCM:
B 2237 H
B 2203 H
B 2283 H
B 2287 H
B 2285 H
B 2263 H
U 1064 H
U 1096 U
Any of this offer any clues?
Thanks
08-28-2015, 09:59 PM
#5
Instructor
Thread Starter
OK ,,,, You seem to be holding back on codes 
My first post requested you post ALL your codes. Not piece meal them out..... Codes are an audit trail of events that have happened. Knowing ALL the codes helps better understand what may be going on.
Are there any other codes?????????
If there are no pressures stored, what is displayed??? XX??????
The LDCM and RDCM codes you have are indicative of battery related issues. They may or may not be recent events. If they are recent events they could easily be the cause of many strange electrical problems. C5 electronics are NOT happy with low voltages.
I suggest you clear ALL the codes.. See the video for how to do that.
Then drive the car for 10 miles or more and then pull the codes again BEFORE you turn off the ignition.. Most codes change from C to H once the engine is shut off. To pull codes with the engine running you MUST use the reset key to clear all messages displayed in the DIC. Then pull codes as normal. INCLUDE the H or C or HC that follow each 5 character code.
Please post ALL the codes that come back in this thread.
My first post requested you post ALL your codes. Not piece meal them out..... Codes are an audit trail of events that have happened. Knowing ALL the codes helps better understand what may be going on.
Are there any other codes?????????
If there are no pressures stored, what is displayed??? XX??????
The LDCM and RDCM codes you have are indicative of battery related issues. They may or may not be recent events. If they are recent events they could easily be the cause of many strange electrical problems. C5 electronics are NOT happy with low voltages.
I suggest you clear ALL the codes.. See the video for how to do that.
Then drive the car for 10 miles or more and then pull the codes again BEFORE you turn off the ignition.. Most codes change from C to H once the engine is shut off. To pull codes with the engine running you MUST use the reset key to clear all messages displayed in the DIC. Then pull codes as normal. INCLUDE the H or C or HC that follow each 5 character code.
Please post ALL the codes that come back in this thread.
Sorry for holding back. I'm shy.The only other codes showing:
28-TCS C 1243 H
60-IPC B 0521 H & U 1160 H
80- RADIO U 1096 H
99-HVAC B 0367 H
I'll drive it tomorrow and recheck. I do appreciate your help
Also the tire pressure readings on the DIC are blank, black, nada, absent, none showing
Last edited by the aeronut; 08-28-2015 at 10:03 PM. Reason: left out information
08-29-2015, 07:46 AM
#6
Le Mans Master
Chuck, looks like you are all over this one but I'll follow in case I think of anything else.
It would seem his door modules are OK and are communicating over the serial bus since the driver door pad/switch (and module) can control the passenger side based on what he said.
Mr. Sam
08-29-2015, 12:52 PM
#7
Instructor
Thread Starter
Battery voltage (engine off) by meter 11.9v
Battery voltage (engine running & while driving) by DIC 13.9v
After driving this morning and following your instructions, I pulled up the codes while engine was still running. The were 0 codes showing in any of the modules. While driving, the tps was giving pressures and was accurate on the one tire I checked with a gauge.
Before driving this morning, I did as you directed and pulled up oil pressure on the DIC and started the car and oil pressure was still showing on the DIC and NOT back to mileage.
One other thing I did was to try and retrain the FOBs. I thought I had a breakthrough when the DIC showed that both had been retrained even though it took far more than the 15 seconds the manual says and even worked as long as I was in the training mode for each particular FOB. However after both had been retrained and the key removed from the ignition neither worked, I have a feeling this might be a significant clue to the problem. Is there an antenna of some sort in any of the modules that picks up the signals from the FOBs?
08-29-2015, 12:57 PM
#8
Instructor
Thread Starter
Mine is a 2000 and I had the same problem. As everything was 15 years old, I replaced the tpms sensors, receiver, and fobs with the kit from Gene. Problem solved for me. That stuff is getting old. You may have a different problem but it sounds just like mine. Good luck, Rod
08-29-2015, 01:40 PM
#9
Instructor
Thread Starter
Your problem is battery. 11.9 volts is WAY low.
I suggest you pull the battery, have it fully charged and then take it to your favorite parts store for a load test.
A good battery at full charge will measure 12.7 to 12.9 volts or more. The electronics in the C5 is not happy with a no load battery voltage of 12.5 or less. The car will start with a no load battery voltage of 12.2 or less but many of the electronics which run diagnostics when the key is inserted. Having voltage when the engine is running from the alternator is too late.
Yes the RFA is a receiver with an antenna. It is located in the left rear of the car above the wheel well. While the FOB's, RFA and TPMS from the early year cars are far from the best, they work adequately for most early year car owners. The replacement "kit consists of 4 new style TPMS, a new RFA , two new style FOB's and the proper adapter for the wiring conversion. Cost last time I looked was in the $450 price range.
This link should help with the RFA location:
https://www.corvetteforum.com/forums...os-please.html
IMHO your money will best be spent for now dealing with the battery issue....
I suggest you pull the battery, have it fully charged and then take it to your favorite parts store for a load test.
A good battery at full charge will measure 12.7 to 12.9 volts or more. The electronics in the C5 is not happy with a no load battery voltage of 12.5 or less. The car will start with a no load battery voltage of 12.2 or less but many of the electronics which run diagnostics when the key is inserted. Having voltage when the engine is running from the alternator is too late.
Yes the RFA is a receiver with an antenna. It is located in the left rear of the car above the wheel well. While the FOB's, RFA and TPMS from the early year cars are far from the best, they work adequately for most early year car owners. The replacement "kit consists of 4 new style TPMS, a new RFA , two new style FOB's and the proper adapter for the wiring conversion. Cost last time I looked was in the $450 price range.
This link should help with the RFA location:
https://www.corvetteforum.com/forums...os-please.html
IMHO your money will best be spent for now dealing with the battery issue....
08-30-2015, 06:54 AM
#10
Le Mans Master
Your battery is DEAD with regard to what the electronics need. The starter needs current more than voltage.
A fully charged battery should be 12.6v or more.
It's not 12 volts it's 12.6 because each cell is 2.1 volts.
If the battery is
12.5 = 85% charged
12.4 = 65%
12.3 = 50%
12.2 = 35%
12.1 = drained
Mr. Sam
A fully charged battery should be 12.6v or more.
It's not 12 volts it's 12.6 because each cell is 2.1 volts.
If the battery is
12.5 = 85% charged
12.4 = 65%
12.3 = 50%
12.2 = 35%
12.1 = drained
Mr. Sam
08-30-2015, 10:50 PM
#11
Instructor
Thread Starter
Your problem is battery. 11.9 volts is WAY low.
I suggest you pull the battery, have it fully charged and then take it to your favorite parts store for a load test.
A good battery at full charge will measure 12.7 to 12.9 volts or more. The electronics in the C5 is not happy with a no load battery voltage of 12.5 or less. The car will start with a no load battery voltage of 12.2 or less but many of the electronics which run diagnostics when the key is inserted. Having voltage when the engine is running from the alternator is too late.
Yes the RFA is a receiver with an antenna. It is located in the left rear of the car above the wheel well. While the FOB's, RFA and TPMS from the early year cars are far from the best, they work adequately for most early year car owners. The replacement "kit consists of 4 new style TPMS, a new RFA , two new style FOB's and the proper adapter for the wiring conversion. Cost last time I looked was in the $450 price range.
Just saw the "kit" for the later year FOB's/TPMS/RFA. Here is a link to that:
https://www.corvetteforum.com/forums...rformance.html
This link should help with the RFA location:
https://www.corvetteforum.com/forums...os-please.html
IMHO your money will best be spent for now dealing with the battery
issue....
I suggest you pull the battery, have it fully charged and then take it to your favorite parts store for a load test.
A good battery at full charge will measure 12.7 to 12.9 volts or more. The electronics in the C5 is not happy with a no load battery voltage of 12.5 or less. The car will start with a no load battery voltage of 12.2 or less but many of the electronics which run diagnostics when the key is inserted. Having voltage when the engine is running from the alternator is too late.
Yes the RFA is a receiver with an antenna. It is located in the left rear of the car above the wheel well. While the FOB's, RFA and TPMS from the early year cars are far from the best, they work adequately for most early year car owners. The replacement "kit consists of 4 new style TPMS, a new RFA , two new style FOB's and the proper adapter for the wiring conversion. Cost last time I looked was in the $450 price range.
Just saw the "kit" for the later year FOB's/TPMS/RFA. Here is a link to that:
https://www.corvetteforum.com/forums...rformance.html
This link should help with the RFA location:
https://www.corvetteforum.com/forums...os-please.html
IMHO your money will best be spent for now dealing with the battery
issue....
08-30-2015, 11:38 PM
#12
Le Mans Master
Bad solders, poor connectors, lousy grounds, low voltage = lot's of C5 headaches 
09-01-2015, 10:34 AM
#13
Instructor
Thread Starter
[QUOTE=8VETTE7;1590383550]Ok, let me see if I'm understanding this. .[/COLOR
'Voltage reading of 12.5 - 12.6 is probably acceptible especially if it was measured with the battery installed in the car.'
] Is this the minimum voltage I should see under a load test?
What is the minimum ambient power needed by the DCMs in order to function properly?
'The fact that the FOB's worked once and then would not work again is MOST likely because of the poor solder joint issue that I provided you a link to in my post #5 above. Usually takes a very powerful magnifying glass and very good eyes to see the cracks or cold solder joints. If you have access to a soldering iron (not a solder gun) then flow the solder on the board as indicated in the link above. I strongly suspect the FOB will work once the solder joints are good. I'm serious when I say the early year FOB's were low quality control junk from the company that supplied them. And yes that is a division of Delco that went bankrupt. (I wonder why???)'
I'm not thinking it's the FOBs because I inspected them under magnification and a small probe to nudge the components to if any were loose. Plus the fact that they work when the ignition switch is on or the car is running. Therefore, I'm inclined to go with your first thought concerning the ambient voltage being supplied to the modules when the car is at rest.
'If I were looking for a replacement battery I would want a min of 700CCA (more is better for me) and I would want the largest reserve time I could get (110 or 120 anyway). I have an overkill battery in my non stock 04 with 850 CCA and 135 reserve.'[/QUOTEWhat is the battery your using that is rated 850CCA & 135 RC? ]
Thanks.
'Voltage reading of 12.5 - 12.6 is probably acceptible especially if it was measured with the battery installed in the car.'
] Is this the minimum voltage I should see under a load test?
What is the minimum ambient power needed by the DCMs in order to function properly?
'The fact that the FOB's worked once and then would not work again is MOST likely because of the poor solder joint issue that I provided you a link to in my post #5 above. Usually takes a very powerful magnifying glass and very good eyes to see the cracks or cold solder joints. If you have access to a soldering iron (not a solder gun) then flow the solder on the board as indicated in the link above. I strongly suspect the FOB will work once the solder joints are good. I'm serious when I say the early year FOB's were low quality control junk from the company that supplied them. And yes that is a division of Delco that went bankrupt. (I wonder why???)'
I'm not thinking it's the FOBs because I inspected them under magnification and a small probe to nudge the components to if any were loose. Plus the fact that they work when the ignition switch is on or the car is running. Therefore, I'm inclined to go with your first thought concerning the ambient voltage being supplied to the modules when the car is at rest.
'If I were looking for a replacement battery I would want a min of 700CCA (more is better for me) and I would want the largest reserve time I could get (110 or 120 anyway). I have an overkill battery in my non stock 04 with 850 CCA and 135 reserve.'[/QUOTEWhat is the battery your using that is rated 850CCA & 135 RC? ]
Thanks.
09-01-2015, 12:42 PM
#14
Le Mans Master
09-01-2015, 02:04 PM
#15
Instructor
Thread Starter
09-03-2015, 11:24 AM
#16
Instructor
Thread Starter
[QUOTE=the aeronut;1590393714]
OK, had the battery load tested. It tested BAD. Bought a new AGM 800 / 120 battery, charged it up, tried to train FOBs. NO JOY! Question: what's left? If the FOBs are defective, why do they work when the ignition is on and I'm training them and not work when the ignition is off and the key removed? Would that not also indicate that the antenna to the DCMs is working? So, everything works OK as long as the ignition switch is on but is dead when the switch is off. As I said, electronics is certainly a mystery to me but my ignorant mind keeps leading me to some issue regarding the static power to the DCMs not being adequate indicating that either the first battery was not all that bad or that the new battery is just as weak as the one it replaced. I'm reluctant to throw any more money at this problem when I can just resort to using my keys for the door. But for some reason it's just frustrating the hell 
out of me that the .... things don't work.
When I charged the new battery it when up to 14.3 v after a few hours but the charger said that was 90 percent charged so I left it at 6 amps overnight overnight but when I checked it the next morning the charger indicated the it was 100 per cent charged but had dropped 12.7 v the multi meter reading was 12.5 with the hood and interior lights drawing which is only .2 v. higher than the old battery.
Ok, let me see if I'm understanding this. .[/COLOR
'Voltage reading of 12.5 - 12.6 is probably acceptible especially if it was measured with the battery installed in the car.'
] Is this the minimum voltage I should see under a load test?
What is the minimum ambient power needed by the DCMs in order to function properly?
'The fact that the FOB's worked once and then would not work again is MOST likely because of the poor solder joint issue that I provided you a link to in my post #5 above. Usually takes a very powerful magnifying glass and very good eyes to see the cracks or cold solder joints. If you have access to a soldering iron (not a solder gun) then flow the solder on the board as indicated in the link above. I strongly suspect the FOB will work once the solder joints are good. I'm serious when I say the early year FOB's were low quality control junk from the company that supplied them. And yes that is a division of Delco that went bankrupt. (I wonder why???)'
I'm not thinking it's the FOBs because I inspected them under magnification and a small probe to nudge the components to if any were loose. Plus the fact that they work when the ignition switch is on or the car is running. Therefore, I'm inclined to go with your first thought concerning the ambient voltage being supplied to the modules when the car is at rest.
'If I were looking for a replacement battery I would want a min of 700CCA (more is better for me) and I would want the largest reserve time I could get (110 or 120 anyway). I have an overkill battery in my non stock 04 with 850 CCA and 135 reserve.'[/QUOTEWhat is the battery your using that is rated 850CCA & 135 RC? ]
Thanks.
'Voltage reading of 12.5 - 12.6 is probably acceptible especially if it was measured with the battery installed in the car.'
] Is this the minimum voltage I should see under a load test?
What is the minimum ambient power needed by the DCMs in order to function properly?
'The fact that the FOB's worked once and then would not work again is MOST likely because of the poor solder joint issue that I provided you a link to in my post #5 above. Usually takes a very powerful magnifying glass and very good eyes to see the cracks or cold solder joints. If you have access to a soldering iron (not a solder gun) then flow the solder on the board as indicated in the link above. I strongly suspect the FOB will work once the solder joints are good. I'm serious when I say the early year FOB's were low quality control junk from the company that supplied them. And yes that is a division of Delco that went bankrupt. (I wonder why???)'
I'm not thinking it's the FOBs because I inspected them under magnification and a small probe to nudge the components to if any were loose. Plus the fact that they work when the ignition switch is on or the car is running. Therefore, I'm inclined to go with your first thought concerning the ambient voltage being supplied to the modules when the car is at rest.
'If I were looking for a replacement battery I would want a min of 700CCA (more is better for me) and I would want the largest reserve time I could get (110 or 120 anyway). I have an overkill battery in my non stock 04 with 850 CCA and 135 reserve.'[/QUOTEWhat is the battery your using that is rated 850CCA & 135 RC? ]
Thanks.
out of me that the .... things don't work. When I charged the new battery it when up to 14.3 v after a few hours but the charger said that was 90 percent charged so I left it at 6 amps overnight overnight but when I checked it the next morning the charger indicated the it was 100 per cent charged but had dropped 12.7 v the multi meter reading was 12.5 with the hood and interior lights drawing which is only .2 v. higher than the old battery.
Last edited by the aeronut; 09-03-2015 at 11:35 AM. Reason: typo
09-03-2015, 12:33 PM
#17
Le Mans Master
Please test the FOBs like 8VETTE7 has requested.
If they test good then it could some issue with the BCM being in the sleep mode when the ignition is OFF. The RFA communicates with the BCM over the serial bus.
If they test good then it could some issue with the BCM being in the sleep mode when the ignition is OFF. The RFA communicates with the BCM over the serial bus.
09-04-2015, 05:23 PM
#18
Instructor
Thread Starter
While I had the thought about sleep mode I discarded it because it sounded like the OP was trying the door locks right after shutting off the engine and they failed. I have been under the impression that 'Sleep Mode" on the BCM did not begin for about 15 - 20 minutes or so. But I suppose that if the BCM is acting up anything is possible.
OP for your Info here is a thread from a short time back where sleep mode of the BCM was the apparent cause of the problem:
https://www.corvetteforum.com/forums...ery-cable.html
While your symptoms are not the same, be ware that a BCM related issue MAY be what is happening on your car. The FOB transmits an unlock or lock command to the RFA. The RFA decodes the command and sends a request to the BCM. The BCM then operates the door lock by grounding the appropriate circuit. Not as simple as the old days anymore...
I suggest that you test the FOB's because they are by far the more common cause of symptoms that more closely match yours.
If the FOB's test good then more problem diagnosis would be the order of the day BEFORE throwing an expensive BCM at the symptoms.
JMHO
OP for your Info here is a thread from a short time back where sleep mode of the BCM was the apparent cause of the problem:
https://www.corvetteforum.com/forums...ery-cable.html
While your symptoms are not the same, be ware that a BCM related issue MAY be what is happening on your car. The FOB transmits an unlock or lock command to the RFA. The RFA decodes the command and sends a request to the BCM. The BCM then operates the door lock by grounding the appropriate circuit. Not as simple as the old days anymore...
I suggest that you test the FOB's because they are by far the more common cause of symptoms that more closely match yours.
If the FOB's test good then more problem diagnosis would be the order of the day BEFORE throwing an expensive BCM at the symptoms.
JMHO
09-08-2015, 11:43 AM
#19
Instructor
Thread Starter
Interesting read about BCM and sleep mode. Some of the symptoms were the same as mine but not as severe. I'll see if I can find someone who can check the FOBs for signal and if that shows no problems with them , I may just use the keys to lock/unlock the doors until some other problem arises that I can't ignore. Most of the GM/Chevy dealers within 60 miles of me, I think, rarely see a Corvette for service so I have my doubts about finding a tech who has much experience with these things. Thanks for your effort to help me out.
In the attachment you will find the section from the Service Manual covering the Keyless Entry Systems ( FOBs, modules etc. ) on the 97-99 cars. The manual then skips to the 2001-2004 cars with no specific information on the year 2000 cars provided. I assume it's the same as the 1999 system. I thought this section might be of value to folks experiencing the same type problems I'm having. Therefore I've provided the section as an attachment.