1st problem: Backup Lights not working
Thread Starter
8th Gear
Joined: May 2017
Posts: 8
Likes: 0
From: Lockport Illinois
1st problem: Backup Lights not working
Looking if anyone has changed the Backup switch on a Automatic 1997 C5? Any pictures or instructions?
Backup lights are not working when in reverse. Bulbs blink when Unlocked and Locked on KeyFOB.
I will check Fuse #2 and Fuse #21 next. Rear View Mirror seems to be working fine, at least the lights in them turn on. (I know I seen those are on the same circuit.)
Anything else I can check easily before I start to trace down each section with a Meter??
I've got a few electrical anomalies going on that I will have to chase down and fix. This car was not driven much and its a beauty but it has a few electrical gremlins going on. The ever elusive ABS and Traction Control Lights come on randomly and then go off for awhile, The Air Conditioning Module takes 10 minutes or so to turn on when you start the car up after sitting for awhile........
So I am starting with the Backup lights and see if i can figure that out since it seems simpler.
Any help would be appreciated!
Backup lights are not working when in reverse. Bulbs blink when Unlocked and Locked on KeyFOB.
I will check Fuse #2 and Fuse #21 next. Rear View Mirror seems to be working fine, at least the lights in them turn on. (I know I seen those are on the same circuit.)
Anything else I can check easily before I start to trace down each section with a Meter??
I've got a few electrical anomalies going on that I will have to chase down and fix. This car was not driven much and its a beauty but it has a few electrical gremlins going on. The ever elusive ABS and Traction Control Lights come on randomly and then go off for awhile, The Air Conditioning Module takes 10 minutes or so to turn on when you start the car up after sitting for awhile........
So I am starting with the Backup lights and see if i can figure that out since it seems simpler.
Any help would be appreciated!
Melting Slicks
Joined: Jun 2002
Posts: 2,246
Likes: 66
From: Middletown CT
If the backup lights flash when you use the key fob the control signal from the BCM is working, microrelay 38 is energizing and fuse 2 is good. The problem is in the backup switch circuit (Park neutral switch for auto). Check fuse 21. If that is good then it is the park neutral switch, or the wiring from the fuse to the park neutral switch, or the wiring from the park neutral switch to the relay Normally Closed contact . If that is all good then you could have a burnt NC contact on the relay.
Last edited by Greg_E; May 12, 2017 at 08:09 PM.
Melting Slicks
Joined: Jun 2002
Posts: 2,246
Likes: 66
From: Middletown CT
There is a TSB on the park neutral switch.
Here is an excerpt.
"Park/Neutral Position Switch Connector Cannot Be Removed (Replace Switch and Connectors) #01-07-30-021 - (May 2, 2001)
Park/Neutral Position Switch Connector Cannot Be Removed (Replace Switch and Connectors)
1997-2001 Chevrolet Camaro, Corvette .........
Condition
Technicians may experience difficulty in removing the connectors from the Park/Neutral Position Switch, usually when trying to remove the switch during transmission service. In rare cases, customers may also report switch related electrical conditions, such as improper or no shift indication, or no back-up light operation.
Cause
High ambient heat may cause the sealing compound in the switch to melt and flow into the connectors, sealing the connectors to the switch. This normally causes no customer concerns, but may cause an open circuit in rare cases.
You may need to replace the switch and connector if you find that is the problem."
The replacement of the switch may not be as simple as you would think. GM has a special tool, J41364-A that aligns the two lower slots with the upper slot in the switch. I have a manual trans. so I've never done this repair, but you may be able to fabricate something that will work. There are a few on Ebay but they are going for $50 or more.
Here is an excerpt.
"Park/Neutral Position Switch Connector Cannot Be Removed (Replace Switch and Connectors) #01-07-30-021 - (May 2, 2001)
Park/Neutral Position Switch Connector Cannot Be Removed (Replace Switch and Connectors)
1997-2001 Chevrolet Camaro, Corvette .........
Condition
Technicians may experience difficulty in removing the connectors from the Park/Neutral Position Switch, usually when trying to remove the switch during transmission service. In rare cases, customers may also report switch related electrical conditions, such as improper or no shift indication, or no back-up light operation.
Cause
High ambient heat may cause the sealing compound in the switch to melt and flow into the connectors, sealing the connectors to the switch. This normally causes no customer concerns, but may cause an open circuit in rare cases.
You may need to replace the switch and connector if you find that is the problem."
The replacement of the switch may not be as simple as you would think. GM has a special tool, J41364-A that aligns the two lower slots with the upper slot in the switch. I have a manual trans. so I've never done this repair, but you may be able to fabricate something that will work. There are a few on Ebay but they are going for $50 or more.
Last edited by Greg_E; May 12, 2017 at 09:00 PM.
Thread Starter
8th Gear
Joined: May 2017
Posts: 8
Likes: 0
From: Lockport Illinois
Fuse #2 is only involved when you use the keyless remote (FOB) to lock/unlock the doors. The BCM momentarily powers the backup bulbs through relay 38 with power from fuse #2 in the Underhood Fuse Box. You know fuse #2 is good because they flash with the FOB. Fuse 2 in the IP fuse box is the one related to the mirror lights.
Fuse #21 in the IP Fuse Box (passenger foot well) is the power source for the backup lights when operated with the trans in reverse. That one could be out. On the automatics the Park/neutral position switch is the mechanism for turning on the reverse lights when the car is in reverse. There is not a reverse switch in the side of the trans like the Manual trans.
Pin #10 in the PNP connector (a grey wire that goes back to relay 38) provides voltage path to the reverse lamps. Normally Closed position of relay 38 provides a path to the light green wire that then goes to each backup lamp. Possibility that relay 38 is bad in the normal position but it DOES switch when your FOB is used since bulbs blink.
For the ABS light the cars Diagnostic Trouble Codes (DTC'S) will provide you some valuable input on what is happening there. Pull and post the codes. If you have never done tht here is how:
https://www.youtube.com/watch?v=SviRjIsy9G4
OR
http://www.c5forum.com/ayc/dtcdic.php
Post ALL the codes including the H or C or HC that follow each 5 character code. List the codes under the sensor thsy show under. ie 10 - PCM or 28 - TCS or 40 - BCM .....etc......
Codes for the ABS will be under 28 - TCS.
I'm a slow typist so I see that Greg has given you some of this info already....
Fuse #21 in the IP Fuse Box (passenger foot well) is the power source for the backup lights when operated with the trans in reverse. That one could be out. On the automatics the Park/neutral position switch is the mechanism for turning on the reverse lights when the car is in reverse. There is not a reverse switch in the side of the trans like the Manual trans.
Pin #10 in the PNP connector (a grey wire that goes back to relay 38) provides voltage path to the reverse lamps. Normally Closed position of relay 38 provides a path to the light green wire that then goes to each backup lamp. Possibility that relay 38 is bad in the normal position but it DOES switch when your FOB is used since bulbs blink.
For the ABS light the cars Diagnostic Trouble Codes (DTC'S) will provide you some valuable input on what is happening there. Pull and post the codes. If you have never done tht here is how:
https://www.youtube.com/watch?v=SviRjIsy9G4
OR
http://www.c5forum.com/ayc/dtcdic.php
Post ALL the codes including the H or C or HC that follow each 5 character code. List the codes under the sensor thsy show under. ie 10 - PCM or 28 - TCS or 40 - BCM .....etc......
Codes for the ABS will be under 28 - TCS.
I'm a slow typist so I see that Greg has given you some of this info already....
Checked Fuse #21 in the passenger footwell, it is good by testing plus I put in a spare one and still the same problem. So no easy fix there. Will have to trace some circuits next I guess.
Here are the codes on my DIC right now. I cleared the codes so I can only worry about the recent ones since I have no idea how much this car was really driven in the last year. So no ABS codes yet but once they come on I will look for those. But here are the codes I have now so anyone can chime in what might be triggering them.
(10-PCM) P1571 H
(40-BCM) B0432 H C
(A0-LDCM) B2264 H
Melting Slicks
Joined: Jun 2002
Posts: 2,246
Likes: 66
From: Middletown CT
If the backup lights flash when you use the key fob the control signal from the BCM is working, microrelay 38 is energizing and fuse 2 is good. The problem is in the backup switch circuit (Park neutral switch for auto). Check fuse 21. If that is good then it is the park neutral switch, or the wiring from the fuse to the park neutral switch, or the wiring from the park neutral switch to the relay Normally Closed contact . If that is all good then you could have a burnt NC contact on the relay.
but its easy to check and if it's not that, it's the park neutral switch or wiring.
If you need to replace the connectors, Rock sells a repair pigtail kit Transmaxx 3523201 or Autozone, Rostra 3500077
Last edited by Greg_E; May 14, 2017 at 09:07 AM. Reason: added info
Thread Starter
8th Gear
Joined: May 2017
Posts: 8
Likes: 0
From: Lockport Illinois
Refer to the schematic I posted. Pull the relay and run a jumper from F9 to E9. If the backup lights work the relay is bad. In my experience things are never that simple,
but its easy to check and if it's not that, it's the park neutral switch or wiring.
If you need to replace the connectors, Rock sells a repair pigtail kit Transmaxx 3523201 or Autozone, Rostra 3500077
but its easy to check and if it's not that, it's the park neutral switch or wiring.
If you need to replace the connectors, Rock sells a repair pigtail kit Transmaxx 3523201 or Autozone, Rostra 3500077
Greg_E,
I am just learning how to do some troubleshooting on this so I am in need of some more information on running the Jumper from E9 to F9. How do I know where this is? And which connectors or wires these are? Like I said, I am a newbie but I am interested in learning.
From the schematic you posted, It looks like this comes from the Relay #38 in the Under Hood Electrical Fuse Panel? Is that correct? And then how do I know which is E9 and which is F9?
Melting Slicks
Joined: Jun 2002
Posts: 2,246
Likes: 66
From: Middletown CT
When you unplug the relay there should be 5 contacts. Two of them go to the coil of the relay and are of no concern to you, as you know that the control circuit is working.
The other three contacts are Common (E9), Normally Closed (F9), and Normally Open (not specified but it is the wire from fuse 2. By putting a jumper from E9 to F9 you are simulating
the NC to Common Contact closure when the relay is deenergized. If the relay is bad the backup lights would work when you put it in reverse with the jumper installed. If the lights still don't work them you need to find where the circuit from Fuse 21 to F9 is open.
I'm tied up with some other things right now. When I get some time I'll try to find some more info for you.
8VETTE7: Who's the slow typist now?
The other three contacts are Common (E9), Normally Closed (F9), and Normally Open (not specified but it is the wire from fuse 2. By putting a jumper from E9 to F9 you are simulating
the NC to Common Contact closure when the relay is deenergized. If the relay is bad the backup lights would work when you put it in reverse with the jumper installed. If the lights still don't work them you need to find where the circuit from Fuse 21 to F9 is open.
I'm tied up with some other things right now. When I get some time I'll try to find some more info for you.
8VETTE7: Who's the slow typist now?
Last edited by Greg_E; May 15, 2017 at 02:38 PM.
Thread Starter
8th Gear
Joined: May 2017
Posts: 8
Likes: 0
From: Lockport Illinois
When you unplug the relay there should be 5 contacts. Two of them go to the coil of the relay and are of no concern to you, as you know that the control circuit is working.
The other three contacts are Common (E9), Normally Closed (F9), and Normally Open (not specified but it is the wire from fuse 2. By putting a jumper from E9 to F9 you are simulating
the NC to Common Contact closure when the relay is deenergized. If the relay is bad the backup lights would work when you put it in reverse with the jumper installed. If the lights still don't work them you need to find where the circuit from Fuse 21 to F9 is open.
I'm tied up with some other things right now. When I get some time I'll try to find some more info for you.
8VETTE7: Who's the slow typist now?
The other three contacts are Common (E9), Normally Closed (F9), and Normally Open (not specified but it is the wire from fuse 2. By putting a jumper from E9 to F9 you are simulating
the NC to Common Contact closure when the relay is deenergized. If the relay is bad the backup lights would work when you put it in reverse with the jumper installed. If the lights still don't work them you need to find where the circuit from Fuse 21 to F9 is open.
I'm tied up with some other things right now. When I get some time I'll try to find some more info for you.
8VETTE7: Who's the slow typist now?
I'm not Greg but I think I can answer your questions. Relay 38 in the under hood fuse box is the one in question.
If you carefully remove the relay from its socket and note how its orientation for proper re-installation, you should see on the side of the relay the layout of the relay contacts. Note which socket the pin labeled as 30 and 87a are in the fuse box socket. 87a is the same as F9 and 30 is the same as E9. Those are the two contacts in the socket that you need to jumper.
Or if you are not comfortable jumpering the contacts you can use a digital multimeter to measure the resistance across the 87a and 30 pin on the relay itself. Resistance should be zero or very close to zero. If not the relay contact surfaces are not making proper electrical contact and the relay needs to be replaced.
If you carefully remove the relay from its socket and note how its orientation for proper re-installation, you should see on the side of the relay the layout of the relay contacts. Note which socket the pin labeled as 30 and 87a are in the fuse box socket. 87a is the same as F9 and 30 is the same as E9. Those are the two contacts in the socket that you need to jumper.
Or if you are not comfortable jumpering the contacts you can use a digital multimeter to measure the resistance across the 87a and 30 pin on the relay itself. Resistance should be zero or very close to zero. If not the relay contact surfaces are not making proper electrical contact and the relay needs to be replaced.
Thank you Guys!
I will look into this when I get the time maybe later today. Of course it probably won't be that simple but I'm crossing my fingers!
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Melting Slicks
Joined: Jun 2002
Posts: 2,246
Likes: 66
From: Middletown CT
This should help.
You would put a jumper from 1524 to 24 and see if the backup lights work when you put it in reverse.
To be on the safe side when troubleshooting you should use a jumper wire with an inline fuse. That way if you were to accidentally put the jumper on the wrong terminal the fuse would blow before you burnt anything up. You can also just test the relay as 8VETTE 7 suggested. Either way the relay needs to come out.
You would put a jumper from 1524 to 24 and see if the backup lights work when you put it in reverse.
To be on the safe side when troubleshooting you should use a jumper wire with an inline fuse. That way if you were to accidentally put the jumper on the wrong terminal the fuse would blow before you burnt anything up. You can also just test the relay as 8VETTE 7 suggested. Either way the relay needs to come out.
Last edited by Greg_E; May 15, 2017 at 04:45 PM.
Thread Starter
8th Gear
Joined: May 2017
Posts: 8
Likes: 0
From: Lockport Illinois
This should help.
You would put a jumper from 1524 to 24 and see if the backup lights work when you put it in reverse.
To be on the safe side when troubleshooting you should use a jumper wire with an inline fuse. That way if you were to accidentally put the jumper on the wrong terminal the fuse would blow before you burnt anything up. You can also just test the relay as 8VETTE 7 suggested. Either way the relay needs to come out.
You would put a jumper from 1524 to 24 and see if the backup lights work when you put it in reverse.
To be on the safe side when troubleshooting you should use a jumper wire with an inline fuse. That way if you were to accidentally put the jumper on the wrong terminal the fuse would blow before you burnt anything up. You can also just test the relay as 8VETTE 7 suggested. Either way the relay needs to come out.
That helps tremendously! I can definitely check the relay itself to make sure it is reading correctly. I should make a jumper wire with an inline fuse for future troubleshooting though. Would be good to have around.
Melting Slicks
Joined: Jun 2002
Posts: 2,246
Likes: 66
From: Middletown CT
The fact that at least two aftermarket companies are selling connector pigtail repair kits suggests that there is a demand for them. I think you will probably wind up replacing the switch and connectors, but go through the process to find what is wrong. It's the only way you will learn.
Thread Starter
8th Gear
Joined: May 2017
Posts: 8
Likes: 0
From: Lockport Illinois
Ok been awhile since I've continued troubleshooting and I just got back from vacation. But found another interesting fact about the backup lights that I'm hoping someone can maybe help pinpoint where the problem might be. I mentioned the Climate Control unit also would not always come on and then it would pop on later down the road. Well found out today the backup lights work when the climate control unit works! So what circuit or ground point do both of these share that might pinpoint the problem area?
Melting Slicks
Joined: Jun 2002
Posts: 2,246
Likes: 66
From: Middletown CT
I don't see the connection but you did have a current DTC for the rear defogger relay circuit. You could try removing the HVAC Minifuse 18 and see if the backup lights work. Clear the codes when your done so you don't get confused later. I really don't see why that would affect the backup lights, but what do I know?
2nd Gear
Joined: Aug 2020
Posts: 2
Likes: 0
Automatic backup light switch location
Where is the switch located on a 2004? I have checked all the fuses and replaced the relay. Lights come on when I hit the FOB but do not come on when vehicle is placed in reverse. The backup camera does not come on either so I believe it is not getting power so I believe it is the switch but I have not been able to get the location. Any help would be appreciated. Thanks!
