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. |
DTC Descriptor
DTC B1420: Device Voltage Circuit - BCM, PSDMDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
B+ | B1420 | B1420 | -- | -- |
Ground | -- | B1420 | -- | -- |
Typical Scan Tool Data
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Operating Conditions: Ignition ON, engine OFF. Parameter Normal Value: 12.60 Volts | |||
B+ | 0.00 Volts | 0.00 Volts | 12.60 Volts |
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Operating Conditions: Ignition ON, engine OFF. Parameter Normal Value: 12.60 Volts | |||
B+ | 0.00 Volts | 0.00 Volts | 12.60 Volts |
Circuit/System Description
The body control module (BCM) and the left and right power sliding door modules (PSDMs) monitor the battery voltage through the battery voltage signal circuit. Damage to components, and incorrect data may occur when the voltage is out of range. If the BCM or PSDM senses that battery voltage is outside of its normal range, DTC B1420 will set.
Conditions for Running the DTC
| • | The voltage supplied to the BCM is in the range of 7-26 volts. |
| • | The ignition is ON. |
Conditions for Setting the DTC
Battery voltage is outside the range of 9-16 volts for 1 second.
Action Taken When the DTC Sets
| • | The control module will disable its outputs when a high voltage condition is detected. |
| • | The control module inhibits the setting of other DTCs. |
Conditions for Clearing the DTC
The DTC passes when the malfunction is no longer present.
Diagnostic Aids
| • | Overcharging with a battery charger and jump starting may set this DTC. |
| • | A high or low voltage value in multiple modules indicates a concern in the charging system. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Charging System Description and Operation
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
- Engine running, accessories OFF, measure and record the voltage at the battery voltage at the battery terminals. The voltage should be between 12.6 and 15.0 volts.
- Observe the scan tool Battery Voltage parameter. The reading should be between 12.6 and 15.0 volts.
| ⇒ | If not within the specified range, refer to Charging System Test . |
Circuit/System Testing
- Ignition OFF, disconnect the harness connectors at the appropriate module.
- Ignition OFF and scan tool disconnected, open and close the driver door, and wait 1 minute. Test for less than 5 ohms between the ground circuit and ground.
- Verify that a test lamp illuminates between the B+ circuit terminals and ground.
- Ignition ON, verify that a test lamp illuminates between the ignition circuit terminals and ground.
- If all circuits test normal, replace the appropriate module.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for the appropriate module replacement, setup, and programming.
