Circuit Description
The body control module (BCM) applies battery voltage to the accessory voltage circuit when the ignition is in the ON position. The folding top control (FTC) module monitors this circuit at least once every 300 milliseconds to determine if voltage is supplied to the following folding top switches:
| • | Top open switch |
| • | Top closed switch |
| • | Luggage barrier switch |
| • | Folding top cover open switch |
| • | 5 bow raised switch |
| • | 5 bow lowered switch |
| • | Pin receiver switch |
DTC Descriptor
The diagnostic procedure supports the following DTC:
DTC B1420 Device Voltage
Conditions for Running the DTC
The FTC module must be powered and can not have B1327 or B1328 set as active DTCs for this DTC to set. The battery voltage is between 9-16 volts.
Conditions for Setting the DTC
| • | If the FTC module detects the accessory voltage dropping below 3 volts. |
| • | The power mode is either in Accessory, RUN, Rap or Crank. |
Action Taken When the DTC Sets
| • | Stores a current and history DTC B1420 in the FTC module. |
| • | The folding top operation is suspended. |
| • | If the condition occurs during operation of the folding top, once the top control switch is released, the FTC module will send a class 2 message to the driver information center (DIC), displaying TOP NOT SECURE. |
Conditions for Clearing the DTC
| • | This DTC will clear on the current status after the condition for setting the fault is corrected. |
| • | A history DTC will clear after 50 consecutive ignition cycles without a fault present. |
| • | History and current DTC can be cleared using the scan tool. |
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Folding Top Schematics Connector End View Reference: Power Roof Systems Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Is DTC B1420 present? | -- | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems |
3 | Measure the accessory voltage at the FTC module harness connector. Does the voltage measure near the specified value? | 9-16 V | Go to Step 5 | Go to Step 4 |
4 |
Does the scan tool display Yes? | -- | Go to Step 6 | Go to Step 7 |
5 | Inspect for poor connections at the harness connector of the folding top control (FTC) module. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 8 |
6 | Repair the high resistance or open in the accessory voltage circuit between the FTC module and the splice. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 9 | -- |
7 | Repair the short to ground or open in the accessory voltage circuit of the FTC module. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 9 | -- |
8 | Replace the FTC module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming . Did you complete the replacement? | -- | Go to Step 9 | -- |
9 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
