Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Bed Sensor Signal | 1 | 1 | 1 | -- |
Ground | -- | 1 | -- | -- |
1. Bed Sensor Malfunction | ||||
Circuit/System Description
The bed sensor is a component of the content theft deterrent (CTD) system which monitors the status of the tailgate. The body control module (BCM) applies B+ to the bed sensor signal circuit. The bed sensor is a switch that opens and closes based on the position of the tailgate. With the switch closed, the signal circuit is switched to ground, indicating the tailgate has been opened. If the content theft deterrent (CTD) system is armed and the BCM sees the tailgate open, the CTD alarm will be activated.
Diagnostic Aids
The bed sensor is a dealer installed accessory. Not all vehicles are equipped with a bed sensor. To determine if a particular vehicle is equipped with a bed sensor, visually inspect the installation location for the sensor based on the information contain in the installation instructions.
Reference Information
Schematic Reference
Theft Deterrent System Schematics
Connector End View Reference
Description and Operation
Content Theft Deterrent (CTD) Description and Operation
Electrical Information Reference
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the bed sensor.
- Test for less than 10 ohms between the ground circuit terminal B and ground.
- Test for B+ between the signal circuit terminal A and ground.
- If all circuits test normal, test or replace the bed sensor.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If not the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
Component Testing
- Ignition OFF, disconnect the harness connector at the bed sensor.
- With the switch open, test for infinite resistance between the signal circuit terminal A and the ground circuit terminal B.
- With the switch closed, test for less then 5 ohms between the signal circuit terminal A and the ground circuit terminal B.
| ⇒ | If not the specified value, replace the bed sensor. |
| ⇒ | If greater than the specified range, replace the bed sensor. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Refer to Control Module References for BCM replacement, setup and programming
