SECURITY Indicator Always On or Flashing. Chevrolet Chevy Suburban

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 1999 🢒 Chevy Suburban - 2WD 🢒 Body and Accessories 🢒 Theft Deterrent 🢒 SECURITY Indicator Always On or Flashing

Theft Deterrent System Components
Theft Deterrent System Schematics Vehicle Theft Deterrent
Cell 10: ECM-B, HORN and A/C COMP Fuses
Cell 10: IGN B Fuse and Ignition Switch
Cell 10: ECM-B, HORN and A/C COMP Fuses
Instrument Cluster: Analog Schematics
Theft Deterrent System Schematic Icons
Cell 14: G200 (1 of 4)
Cell 14: G103 and G104
Theft Deterrent System Schematic Icons
Theft Deterrent System Schematic Icons
Theft Deterrent System Schematic Icons
Theft Deterrent System Schematic Icons

Circuit Description

The Security Indicator Always On or Flashing check is designed to find out the reason the Security indicator is staying on or flashing. However, the Theft Deterrent System Diagnostic System Check must always be the starting point for all Passlock system troubleshooting.

The Diagnostics in this table are designed to troubleshoot non DTC troubles. For example Battery power, Ignition 1 input, and shorted or open SECURITY indicator circuit.

Diagnostic Aids

•	Perform a visual check of the wiring and connectors.

•	Refer to Intermittents and Poor Connections

Test Description

The numbers below refer to the numbers in the diagnostic table.

This step will determine if the EVO/Passlock module or the harness is causing the Security Indicator to stay on.

This step determines if there is a short to ground in CKT 749.

This step tests for an open in the class 2 line between Passlock terminal B4 and Splice S280.

This step verifies if the security fuse randomly opened.

This step tests for a short to ground in CKT 1740.

This step tests for Ignition voltage at B3

This step tests for battery input to the EVO/Passlock module.

Step

Action

Value(s)

Yes

Did you perform the Passlock System Check?

Go to Step 2

Go to Diagnostic System Check - Theft Deterrent

Did the SECURITY telltale turn on with the ignition off?

Go to Step 16

Go to Step 3

Turn the ignition switch to the LOCK position.
Disconnect the Passlock module. Refer to Theft Deterrent Module Replacement .
Turn the ignition switch to the ON position.

Did the security indicator turn off?

Go to Step 6

Go to Step 4

Disconnect the Instrument Cluster connector.
Using the J 39200 , measure the resistance from connector terminal B2 of the EVO/Passlock module to ground.

Is the resistance within the specified value?

OL (Infinite)

Go to Step 18

Go to Step 5

Repair the short to ground in circuit 749.

Is the repair complete?

Go to Diagnostic System Check - Theft Deterrent

Using the J 39200 , measure the resistance from connector terminal B4 of the EVO/Passlock module to connector terminal 2 of the data link connector (DLC).

Is the resistance within the specified value?

0-5 ohms

Go to Step 8

Go to Step 7

Repair the open in circuit 1807 between Splice S280 and terminal B4 of the EVO/Passlock module.

Is the repair complete?

Go to Diagnostic System Check - Theft Deterrent

Test the Security Fuse.

Is the Security fuse open?

Go to Step 9

Go to Step 12

Turn the ignition switch to the OFF position.
Reconnect the EVO/Passlock module.
Replace the Security fuse.
Turn the Ignition switch to the ON position.

Is the Security fuse open?

Go to Step 10

Go to Diagnostic System Check - Theft Deterrent

Turn the Ignition switch to the OFF position.
Disconnect the EVO/Passlock module. Refer to Theft Deterrent Module Replacement
Using the J 39200 , measure the resistance from connector terminal B8 of the EVO/Passlock module to ground.

Is the resistance within the specified value?

OL (Infinite)

Go to Step 17

Go to Step 11