Question about security light
07-01-2007, 09:56 PM
#1
Question about security light I just bought a 1998 Z28 and the security light came on about a month or so before I bought it. I have done a lot of reading up about the VATS system and the keys being worn down and resistors and all that. I tried cleaning both my normal key and the spare one and the light is still on. Would finding out the resistor I need to bypass the VATS system be my next best bet? I was thinking about getting a new key made but I figure if using the spare, which isn't worn down around the edges and stuff, still doesn't fix it, I should just bypass the VATS? I already took apart under the steering wheel and noticed what i need to do i just need to go to radio shack and get the key meter tested for the right resistor. Should I go ahead and do this or is there something else I should check before doing this? Oh btw i tried cleaning inside the key hole but what do you guys use to clean in there since the space is so small. and also all the wires are connected near the VATS wires but i haven't taken apart the ignition module or whatever yet. Thanks in advance.
07-02-2007, 09:11 PM
#4
TECH Resident
iTrader: (3)
Join Date: Nov 2001
Location: Lake Delton, WI
Posts: 811
Likes: 0
Received 0 Likes
on
0 Posts
no, there is a procedure...
here it is right from the service manual:
If a malfunction occurs in a system monitored by the BCM, the BCM stores a diagnostic trouble code (DTC) in memory. DTCs are stored by the BCM as either current or history codes. A current DTC means that the fault was present when the diagnostic mode was entered. A history DTC means the fault occurred sometime after the DTCs were last cleared from the BCM memory. History codes are displayed even though the fault is not currently present. If a current DTC is stored the corresponding history code will always be stored. In the diagnostic mode the BCM displays any DTCs stored in memory. The DTCs are displayed as flash codes through the security indicator lamp on the instrument cluster (IPC). When working on any system controlled by the BCM the technician should always refer to this section and check for DTCs.
Perform the following steps to enter the BCM diagnostic mode:
* Turn the ignition switch to the RUN position.
* Turn the ignition switch to the OFF position.
* Remove the Radio fuse 17 from the I/P fuse block.
* Turn the ignition switch to the ACCY position (the BCM sounds 1 or 2 audible warning tones).
* Within five seconds, turn the ignition switch to the OFF position and immediately (within 1 second) back to the ACCY position (the BCM sounds three audible warning tones to signal entry into the diagnostic mode).
The BCM will begin flashing trouble codes four seconds after entering the diagnostic mode. Each flash of the security indicator lamp on the IPC represents a number. For example, one flash followed by two quick flashes represents code 12. Each code is displayed three times before the next code is displayed. Stored DTCs are displayed in numerical order. Once the last code is displayed, the list begins again with the first code. The display continues until the diagnostic mode is exited.
When in the diagnostic mode, a change at certain BCM inputs will cause the BCM to respond to the change. For example, if either door lock switch is pressed the BCM will flash the fasten seatbelt indicator on the IPC and sound an audible warning tone. The BCM will also attempt to perform the operation normally performed by the switch operation. In this case, as long as the system is functioning properly, the BCM will lock the doors. This is an easy way for the technician to test the door lock actuators, switches and associated wiring without removing the door trim or components.
The BCM will also respond to a change at either shock sensor input. The tamper input is activated by minor blows to the vehicle. The shock input is activated by heavy blows. In the diagnostic mode either will cause the BCM to activate the horn relay and the horns will sound. The BCM will also flash the fasten seatbelt indicator on the IPC and sound an audible warning tone. An effective method of checking the shock sensor and associated wiring is to tap on the shock sensor while in the diagnostic mode.
Switching the interior lamps switch on and off while in the diagnostic mode will cause the BCM to flash the fasten seatbelt indicator on the IPC, sound an audible warning tone, and flash the courtesy lamps. On vehicles equipped with theft deterrent, each transition of the interior lamps command input will cause the BCM to step to next action in the following list:
1. Courtesy lamps flash
2. Horns sound
3. Exterior lights flash
DTC Display Order
In the diagnostic mode, diagnostic trouble codes (DTCs) are displayed in the following order:
1. DTC 12
2. Any current DTCs (DTC 21-DTC 25) or any history DTCs (DTC 31-DTC 35)
3. The remote control door lock transmitter diagnostic DTCs (DTC 41-DTC 45)
4. These DTCs will display if they are evoked while in the diagnostic mode. The begin configuration display (DTC 55). DTC 55 and 2 configuration numbers are always displayed. The first number following DTC 55 is the hardware configuration. The second number is the software configuration.
5. After the configuration numbers are displayed, the entire list is repeated beginning with DTC 12.
DTC 12 is always set and displayed when the body control module (BCM) is in the diagnostic mode. DTC 12 indicates that the diagnostic function is in progress. DTC 55 is also always displayed.
If DTC 12 and DTC 55 are displayed when the BCM is in the diagnostic mode, and no other DTCs are displayed, the BCM is operating properly.
If DTC 12 and DTC 55 are not displayed when the BCM is in the diagnostic mode, refer to DTC 12 Diagnostic System Check .
If any other DTCs are displayed, refer to Diagnostic Trouble Code (DTC) List/Type .
System faults are stored as current or history DTCs. When working on systems controlled by the body control module, always refer to this section and test for DTCs.
Intermittent and History DTCs
History DTCs are codes that indicate that the BCM detected a fault which has disappeared.
Any DTC that begins with the digit 3 is a history DTC.
The fault will be stored as a history code under either of the following conditions:
* The fault is an intermittent failure.
* The fault exists in a system which is not currently being operated.
If you cannot determine the cause of the failure through visual inspection, complete the following steps:
1. Connect a DVM to the suspected circuit.
2. Drive the vehicle.
3. Observe the readings. An abnormal voltage or resistance reading when the failure occurs indicates that the condition may be in the suspected circuit.
Here's how to clear them:
Here's the codes and what they are:
DTC 12 Diagnostic System Check
DTC 21/31 Courtesy Lamps Feed Shorted to Ground
DTC 22/32 Courtesy Lamps Return Shorted to Battery
DTC 23/33 RAP Feed Shorted to Ground or Battery
DTC 24/34 Seatbelt Indicator Shorted to Ground or Battery
DTC 25/35 Security Indicator Status
DTC 41 Last Message Received Valid
DTC 42 Last Message Received Invalid
DTC 43 Last Message Received with Sumcheck Error
DTC 44 Last Message Received with Encryption Error
DTC 45 Receiver Processing in 20 Second Lockout
DTC 55 Begin Configuration Display
here it is right from the service manual:
If a malfunction occurs in a system monitored by the BCM, the BCM stores a diagnostic trouble code (DTC) in memory. DTCs are stored by the BCM as either current or history codes. A current DTC means that the fault was present when the diagnostic mode was entered. A history DTC means the fault occurred sometime after the DTCs were last cleared from the BCM memory. History codes are displayed even though the fault is not currently present. If a current DTC is stored the corresponding history code will always be stored. In the diagnostic mode the BCM displays any DTCs stored in memory. The DTCs are displayed as flash codes through the security indicator lamp on the instrument cluster (IPC). When working on any system controlled by the BCM the technician should always refer to this section and check for DTCs.
Perform the following steps to enter the BCM diagnostic mode:
* Turn the ignition switch to the RUN position.
* Turn the ignition switch to the OFF position.
* Remove the Radio fuse 17 from the I/P fuse block.
* Turn the ignition switch to the ACCY position (the BCM sounds 1 or 2 audible warning tones).
* Within five seconds, turn the ignition switch to the OFF position and immediately (within 1 second) back to the ACCY position (the BCM sounds three audible warning tones to signal entry into the diagnostic mode).
The BCM will begin flashing trouble codes four seconds after entering the diagnostic mode. Each flash of the security indicator lamp on the IPC represents a number. For example, one flash followed by two quick flashes represents code 12. Each code is displayed three times before the next code is displayed. Stored DTCs are displayed in numerical order. Once the last code is displayed, the list begins again with the first code. The display continues until the diagnostic mode is exited.
When in the diagnostic mode, a change at certain BCM inputs will cause the BCM to respond to the change. For example, if either door lock switch is pressed the BCM will flash the fasten seatbelt indicator on the IPC and sound an audible warning tone. The BCM will also attempt to perform the operation normally performed by the switch operation. In this case, as long as the system is functioning properly, the BCM will lock the doors. This is an easy way for the technician to test the door lock actuators, switches and associated wiring without removing the door trim or components.
The BCM will also respond to a change at either shock sensor input. The tamper input is activated by minor blows to the vehicle. The shock input is activated by heavy blows. In the diagnostic mode either will cause the BCM to activate the horn relay and the horns will sound. The BCM will also flash the fasten seatbelt indicator on the IPC and sound an audible warning tone. An effective method of checking the shock sensor and associated wiring is to tap on the shock sensor while in the diagnostic mode.
Switching the interior lamps switch on and off while in the diagnostic mode will cause the BCM to flash the fasten seatbelt indicator on the IPC, sound an audible warning tone, and flash the courtesy lamps. On vehicles equipped with theft deterrent, each transition of the interior lamps command input will cause the BCM to step to next action in the following list:
1. Courtesy lamps flash
2. Horns sound
3. Exterior lights flash
DTC Display Order
In the diagnostic mode, diagnostic trouble codes (DTCs) are displayed in the following order:
1. DTC 12
2. Any current DTCs (DTC 21-DTC 25) or any history DTCs (DTC 31-DTC 35)
3. The remote control door lock transmitter diagnostic DTCs (DTC 41-DTC 45)
4. These DTCs will display if they are evoked while in the diagnostic mode. The begin configuration display (DTC 55). DTC 55 and 2 configuration numbers are always displayed. The first number following DTC 55 is the hardware configuration. The second number is the software configuration.
5. After the configuration numbers are displayed, the entire list is repeated beginning with DTC 12.
DTC 12 is always set and displayed when the body control module (BCM) is in the diagnostic mode. DTC 12 indicates that the diagnostic function is in progress. DTC 55 is also always displayed.
If DTC 12 and DTC 55 are displayed when the BCM is in the diagnostic mode, and no other DTCs are displayed, the BCM is operating properly.
If DTC 12 and DTC 55 are not displayed when the BCM is in the diagnostic mode, refer to DTC 12 Diagnostic System Check .
If any other DTCs are displayed, refer to Diagnostic Trouble Code (DTC) List/Type .
System faults are stored as current or history DTCs. When working on systems controlled by the body control module, always refer to this section and test for DTCs.
Intermittent and History DTCs
History DTCs are codes that indicate that the BCM detected a fault which has disappeared.
Any DTC that begins with the digit 3 is a history DTC.
The fault will be stored as a history code under either of the following conditions:
* The fault is an intermittent failure.
* The fault exists in a system which is not currently being operated.
If you cannot determine the cause of the failure through visual inspection, complete the following steps:
1. Connect a DVM to the suspected circuit.
2. Drive the vehicle.
3. Observe the readings. An abnormal voltage or resistance reading when the failure occurs indicates that the condition may be in the suspected circuit.
Current DTCs (21 to 25) remain stored by the body control module (BCM) and are displayed in the diagnostic mode as long as the BCM detects the fault. Once the fault is corrected, the current DTCs are cleared by the BCM. To clear history DTCs (31 to 35) press and hold the door unlock switch for four seconds while the BCM is in the diagnostic mode. The BCM will sound three audible warning tones to confirm that the DTCs are cleared.
To clear BCM history DTCs on vehicles without power door locks, backprobe with a fused jumper from BCM connector C1 terminal D to ground for four seconds. The BCM will sound three audible warning tones to confirm that the history DTCs have been cleared.
To clear BCM history DTCs on vehicles without power door locks, backprobe with a fused jumper from BCM connector C1 terminal D to ground for four seconds. The BCM will sound three audible warning tones to confirm that the history DTCs have been cleared.
DTC 12 Diagnostic System Check
DTC 21/31 Courtesy Lamps Feed Shorted to Ground
DTC 22/32 Courtesy Lamps Return Shorted to Battery
DTC 23/33 RAP Feed Shorted to Ground or Battery
DTC 24/34 Seatbelt Indicator Shorted to Ground or Battery
DTC 25/35 Security Indicator Status
DTC 41 Last Message Received Valid
DTC 42 Last Message Received Invalid
DTC 43 Last Message Received with Sumcheck Error
DTC 44 Last Message Received with Encryption Error
DTC 45 Receiver Processing in 20 Second Lockout
DTC 55 Begin Configuration Display