DTC B19F4

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 P19F4 Vehicle 12V Charging System For symptom byte information refer to Symptom Byte List. Circuit/System Description The control module(s) monitor the system voltage on the B+ circuit and ignition circuit to ensure that it stays within the proper range. An open or high resistance on ground circuit may affect the modules ability to monitor and report the correct system voltage. Conditions for Running the DTC Ignition On Conditions for Setting the DTC B+ circuit is less than 9 V for more than 5 s B+ circuit is greater than 15 V for more than 5 s Ground circuit has an open or high resistance Actions Taken When the DTC Sets A message and/or warning indicator may be displayed to the driver The control module may be disabled Conditions for Clearing the DTC The conditions for setting the DTC are no longer present A history DTC will clear after 100 consecutive ignition cycles without a fault Diagnostic Aids A high or low voltage DTC set or voltage value in multiple modules/sensors indicates a concern in the 12 V charging system. A possible cause of this DTC could be overcharging with a 12 V battery charger or jump starting. The last 2 digits of the circuit number are significant in identifying its power and ground functions. – Circuits ending in 42 are primary fused B+ circuits (generally the first fuse in the circuit after the battery) – Circuits ending in 40 are secondary fused circuits (generally fuses in a fuse block after the primary circuit) – Circuits ending in 39 and 41 are ignition voltage circuits. – Circuits ending in 50 are grounds. – Circuits ending in 51 are low reference (ground) circuits. Reference Information Schematic Reference Starting and Charging Schematics Power Moding Schematics Control Module References Connector End View Reference Master Electrical Component List Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs DTC Type Reference Powertrain Diagnostic Trouble Code (DTC) Type Definitions Scan Tool Reference Control Module References Circuit/System Verification

1. Ignition ON.

Note

A low or high voltage DTC may set in multiple control modules due to a concern with the battery or charging system.

2. Verify there are no system voltage DTCs set as current or history in any control module. ⇒ If any system voltage DTCs are set Diagnose these DTCs first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle. ⇓ If not system voltage DTCs are set
3. Ignition Off and all vehicle systems OFF.

Note

The battery voltage should stabilize after a few minutes of turning the ignition/vehicle Off.

4. Verify the battery voltage is between 12.4 V to 12.8 V at the C1 Battery. ⇒ If not between the specified range Refer to Battery Inspection/Test ⇓ If between the specified range
5. Start the engine with all accessories off, allow the system voltage to stabilize.
6. Test for 13 V to 15 V at the C1 Battery. ⇒ If not the specified value Refer to Charging System Test ⇓ If between the specified range
7. Verify DTC P19F4 is set as current. ⇒ If DTC P19F4 is set as current Refer to Circuit/System Testing. ⇓ If DTC P19F4 is not set as current
8. A fault is not currently present and may be an intermittent condition. Circuit/System Testing

Note

Use the schematics to verify the items listed below: – The control module’s B+ and ground circuits. – The Control module Terminal numbers. Some control module ground circuits may require up to 20 min after the ignition is turned Off before achieving a resistance reading of less than 5 Ω. In most cases the readings will drop below 20 Ω within 1 min indicating the control modules are going to sleep.

1. Ignition Off, disconnect the connector at the appropriate control module.
2. Verify a test lamp illuminates between each module ground circuit terminal and B+ ⇒ If the test lamp does not illuminate Repair the open/high resistance on the ground circuit or the ground connection. ⇓ If the test lamp illuminates
3. Ignition ON.
4. Verify a test lamp Illuminates between modules B+ circuit terminal and ground. ⇒ If the test lamp does not illuminate and the circuit fuse is good 4.1. Test the B+ circuit for an open/high resistance. ⇒ if an open/high resistance is found, repair the fault on the circuit. ⇓ If an open or high resistance is not found 4.2. Verify the fuse is not open and there is voltage at the fuse. ⇒ If the test lamp does not illuminate and the circuit fuse is open 4.1. Test the B+ circuit a short to ground ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found 4.2. Replace the appropriate control module. ⇓ If the test lamp illuminates
5. Verify voltage at each B+ circuit terminal is within 1 V of the C1 Battery voltage. ⇒ If not the specified value Repair the high resistance on the B+ circuit. ⇓ If the specified value
6. Ignition On
7. Verify voltage at each control module ignition circuit terminal is within 1 V of the C1 Battery voltage. ⇒ If not the specified value Repair the high resistance on the ignition circuit. ⇓ If the specified value
8. Replace the control module. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Control Module References for control module replacement, programming, and setup