2010 Cadillac CTS Sedan AWD V6-3.6L Page 1215
Control Module References (See: Testing and Inspection/Programming and Relearning)for scan tool information
Circuit/System Verification
Ignition ON, command the fuel pump ON and OFF using the scan tool ECM fuel pump output control. The fuel pump should turn ON and OFF.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the G12 fuel pump.
2. Connect a test lamp between the control circuit terminal 1 and ground.
3. Ignition ON, command the G12 fuel pump ON and OFF with a scan tool. The test lamp should turn ON and OFF, as commanded.
瀚慖f the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K27 fuel pump control
module.
瀚慖f the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace
the K27 fuel pump control module.
4. Ignition OFF, connect a test lamp between the control circuit terminal 1 and the low reference circuit terminal 2.
5. Ignition ON, command the G12 fuel pump ON with a scan tool. The test lamp should illuminate.
瀚慖f the test lamp does not illuminate, test the low reference circuit terminal 2 for a short to voltage or an open/high resistance. If the circuit
tests normal, replace the K27 fuel pump control module.
6. If all circuits test normal, replace the G12 fuel pump.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Fuel Tank Fuel Pump Module Replacement - Right Side (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Pump/Service
and Repair/Fuel Tank Fuel Pump Module Replacement - Right Side)
* Control Module References (See: Testing and Inspection/Programming and Relearning)for fuel pump control module replacement, setup,
and programming
P258A
DTC P258A-P258D
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P258A
- Vacuum Pump Relay Control Circuit
DTC P258B
- Vacuum Pump Performance
DTC P258C
- Vacuum Pump Relay Control Circuit Low Voltage
DTC P258D
- Vacuum Pump Relay Control Circuit High Voltage
Diagnostic Fault Information
