For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Theft Deterrent System Schematics Connector End View Reference: Theft Deterrent System Connector End Views DEFINITION: The content theft deterrent (CTD) alarm is always ON.
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Disconnect the intelligent switching unit (ISU). Does the alarm turn off? | Go to Step 5 | Go to Step 3
3 |

1. Disconnect the theft deterrent alarm.
2. Test for a short to ground in the alarm ground. Refer to Testing for Short to Ground and Wiring Repairs .

Did you find and correct the condition?

Go to Step 8

Go to Step 4

4 | Test for a poor connection at the theft deterrent alarm. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 8 | Go to Step 7
5 | Test for a poor connection at the ISU. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 8 | Go to Step 6
6 | Important: Perform the program procedure for the ISU. Replace the ISU. Did you complete the replacement? | Go to Step 8 | --
7 | Replace the theft deterrent alarm. Refer to Theft Deterrent Alarm Replacement . Did you complete the replacement? | Go to Step 8 | --
8 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2