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New to the forums. Bought this car because i wanted to learn how to work on cars so I rather learn to fix things myself than take to dealer!
Have an automatic 2002 and its having issues starting which I am left to believe is electrical. Maybe BCM itself or the PNP switch?
NOTE: Battery gauge reads 11.8V which i read in another forum that the gauge can be off a bit so this is within range? Battery has been load tested and passed and then it was also charged as well.
Originally replaced the ignition switch due to symptoms of failure (no start 1x but would fire up after / flickering gauges and lights.) Had the battery tested and it was fine so figured the common failure point was the problem.
Issue was fixed for maybe 3 weeks then it wouldn’t start from cold (no crank when key turned to START.) At this point key relearn procedure (where it was left in ON for 11 min then off for 30s then repeat) would allow the car to start up a few times (1-3) but then back to no crank.
At this point i had taken the car to be tested for alternator, starter, and battery load tested then charged. All passed.
Thought maybe starter was culprit so ordered replacement and swapped (I do believe starter and solenoid are together as 1 piece) and still no start. Key relearn procedure again would work so car would start maybe 1-2x.
Checked passenger footwell fuse box and MAXIfuse 50 (IGN2) was not testing as working with voltmeter (others tested would beep and 50 would not.) When pulled 50 was corroded and so i changed it and it still did not fix the issue.
Next up lock cylinder was swapped today after having it keyed by a lock smith. Issue not resolved and now key relearn is not working so car will not start at all.
Security light is blinking.
When turning key to START the TDR will click so i believe its being energized from upstream in the circuit? I am no good with circuits but I am willing to learn.
Saw in another forum to check purple wire in the TDR to ensure its receiving 12V when key is turned to START.
How do I test the voltage in this wire? I am not sure where to physically put the red test lead on the purple wire, there is no exposed part of the wire to make contact with (as is normal)
I am left to believe maybe the BCM is not working properly? Or the PNP switch could be it?
Was working with the schematic attached.
Current codes are as follows:
RTD B2795 H C
HVAC B0338 H C
LDCM B2282 H
LDCM B2286 H
LDCM B2284 H
LDCM B2262 H
LDCM B2264 H
LDCM U1064 H
RDCM B2283 H
RDCM B2287 H
RDCM B2285 H
RDCM B2263 H
RDCM B2265 H
RDCM U1064 H
New to the forums. Bought this car because i wanted to learn how to work on cars so I rather learn to fix things myself than take to dealer!
Have an automatic 2002 and its having issues starting which I am left to believe is electrical. Maybe BCM itself or the PNP switch?
NOTE: Battery gauge reads 11.8V which i read in another forum that the gauge can be off a bit so this is within range? Battery has been load tested and passed and then it was also charged as well.
Originally replaced the ignition switch due to symptoms of failure (no start 1x but would fire up after / flickering gauges and lights.) Had the battery tested and it was fine so figured the common failure point was the problem.
Issue was fixed for maybe 3 weeks then it wouldn’t start from cold (no crank when key turned to START.) At this point key relearn procedure (where it was left in ON for 11 min then off for 30s then repeat) would allow the car to start up a few times (1-3) but then back to no crank.
At this point i had taken the car to be tested for alternator, starter, and battery load tested then charged. All passed.
Thought maybe starter was culprit so ordered replacement and swapped (I do believe starter and solenoid are together as 1 piece) and still no start. Key relearn procedure again would work so car would start maybe 1-2x.
Checked passenger footwell fuse box and MAXIfuse 50 (IGN2) was not testing as working with voltmeter (others tested would beep and 50 would not.) When pulled 50 was corroded and so i changed it and it still did not fix the issue.
Next up lock cylinder was swapped today after having it keyed by a lock smith. Issue not resolved and now key relearn is not working so car will not start at all.
Security light is blinking.
When turning key to START the TDR will click so i believe its being energized from upstream in the circuit? I am no good with circuits but I am willing to learn.
Saw in another forum to check purple wire in the TDR to ensure its receiving 12V when key is turned to START.
How do I test the voltage in this wire? I am not sure where to physically put the red test lead on the purple wire, there is no exposed part of the wire to make contact with (as is normal)
I am left to believe maybe the BCM is not working properly? Or the PNP switch could be it?
Was working with the schematic attached.
Current codes are as follows:
RTD B2795 H C
HVAC B0338 H C
LDCM B2282 H
LDCM B2286 H
LDCM B2284 H
LDCM B2262 H
LDCM B2264 H
LDCM U1064 H
RDCM B2283 H
RDCM B2287 H
RDCM B2285 H
RDCM B2263 H
RDCM B2265 H
RDCM U1064 H
SCM B0851 H
RFA U1255 H
No offense intended. There are vast resources on this forum that can help you work on the C5 platform. So you are "learning how to work on cars", and lack the basic knowledge of just how things work.....proper tools required, etc....and boy did you pick a platform to learn on In order to effectively troubleshoot problems on a C5, you need to be able to comprehend the service manual, be able to read schematics, own (and know how to use) a test light and DMM. I recommend you take your car to a trusted electric shop for repair. That will get you up and running. Then you can pair up with someone that can work shoulder-to-shoulder with you so you can learn in real time while having the satisfaction of doing your own repairs.
The Security light should flash a few times and then go off. You state that you can hear the TDR click on when the key is turned to the start position, that is a good thing. You can measure voltage between the violet wire and ground, simply insert the red test lead up into the TDR socket where the violet wire is at. The TDR itself maybe at fault, even though the relay clicks on its contacts maybe be worn and pitted.
Battery voltage can ONLY be accurately measured at the battery terminals with a volt meter. 11.8 is LOW. Do not rely on the DIC or indication on the instrument cluster.
C5's exhibit all sorts of symptoms if battery voltage is low. Your best bet is a new Optima Red Top and a good battery maintainer.
2002 No Crank, Security Light Blinking
In order to effectively troubleshoot problems on a C5, you need to be able to comprehend the service manual, be able to read schematics, own (and know how to use) a test light and DMM. I recommend you take your car to a trusted electric shop for repair. That will get you up and running. Then you can pair up with someone that can work shoulder-to-shoulder with you so you can learn in real time while having the satisfaction of doing your own repairs. 
