B3930
DTC B3930
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptor
DTC B3930 02
- Child Security Lock Motors Circuit Short to Ground
Diagnostic Fault Information
Circuit/System Description
The child door lockout switch is on the driver door lock/window switch and controls the child locks on the rear doors as well as the rear window switches. When the BCM receives a command from the window lockout switch, it will apply voltage to the door lock security relay coil, this will energize the relay and the contact within the relay will then direct the voltage to lock the left rear and right rear child locks and then isolate them from the normal door lock system to prevent the rear doors from being opened by using the interior rear door handles.
Conditions for Running the DTC
Battery voltage must be between 9-16 V.
Conditions for Setting the DTC
The BCM detects a short to ground in the child security lock relay circuit.
Action Taken When the DTC Sets
* The interior rear door handles will always be disabled or will not lockout depending upon the latch states when the fault occurred
* The BCM will command the lockout indicator to flash ON and OFF for 30 seconds when the lockout switch is pressed to indicate a fault in the system.
Conditions for Clearing the DTC
* This DTC will be current for as long as the fault is present.
* When the fault is no longer present, the DTC will be a history DTC.
* A history DTC will clear after 50 ignition cycles.
Reference Information
Schematic Reference
Door Lock/Indicator Schematics Door Lock/Indicator Schematics
Connector End View Reference
Component Connector End Views Hybrid/EV Battery Pack X1
Description and Operation
Power Door Locks Description and Operation Description and Operation
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Programming and Relearning for scan tool information
Circuit/System Verification
1. Vehicle in Service Mode.
2. Verify the operation of both interior rear door handles do not open the rear doors when commanding the Child Security Lock Motors ON with a scan tool.
• If both interior door handles open the rear doors
Refer to Circuit/System Testing.
• If both interior door handles do not open the rear doors
3. Verify the operation of both interior rear door handles will open the rear doors when commanding the Child Security Lock Motors OFF with a scan tool.
• If both interior door handles do not open the rear doors
Refer to Circuit/System Testing.
• If both interior door handles open the rear doors
4. All OK.
Circuit/System Testing
1. Vehicle OFF and all vehicle systems OFF, disconnect the KR97 door lock relay. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the ground circuit terminal 58 and ground.
• If 10 ohms or greater
1. Vehicle OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms
3. Connect a test lamp between the control circuit terminal 54 and the ground circuit terminal 58.
4. Verify the test lamp turns ON and OFF when commanding the Child Security Lock Motors ON and OFF with a scan tool.
• If the test lamp is always OFF
1. Vehicle OFF, disconnect the harness connector at the K9 body control module.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the control circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 body control module.
• If the test lamp is always ON
1. Vehicle OFF, disconnect the harness connector at the K9 body control module, Vehicle in Service Mode.
2. Test for less than 1 V between the control circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K9 body control module.
• If the test lamp turns ON and OFF
5. Test or replace the KR97 door lock relay.
Component Testing
Relay Test
1. Vehicle OFF, disconnect the KR97 door lock relay.
2. Test for 60-200 ohms between terminals 54 and 58.
• If less than 60 ohms or greater than 200 ohms
Replace the KR97 door lock relay.
• If between 60-200 ohms
3. Test for infinite resistance between the terminals listed below:
* 54 and 56
* 54 and 55
* 58 and 56
* 58 and 55
• If less than infinite resistance
Replace the KR97 door lock relay.
• If infinite resistance
4. Install a 3 A fused jumper wire between relay terminal 54 and 12 V. Install a jumper wire between relay terminal 58 and ground.
5. Test for less than 2 ohms between terminals 46 and 45.
• If 2 ohms or greater
Replace the KR97 door lock relay.
• If less than 2 ohms
6. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Relay Replacement (Within an Electrical Center) Relay Replacement (Within an Electrical Center)Relay Replacement (Attached to Wire Harness) Relay Replacement (Attached to Wire Harness)
* Control Module References Programming and Relearning for BCM replacement, programming and setup