2010 Cadillac CTS Sedan AWD V6-3.6L Page 1218
5. Test for less than 2 ohms between terminals 30 and 87.
瀚慖f greater than the specified range, replace the relay.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Relay Replacement (Attached to Wire Harness) (See: Power and Ground Distribution/Power Distribution Relay/Service and Repair/Relay
Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (See: Power and Ground Distribution/Power
Distribution Relay/Service and Repair/Relay Replacement (Within an Electrical Center))
* Power Brake Booster Auxiliary Pump Replacement (See: Brakes and Traction Control/Power Brake Assist/Hydraulic Brake Booster
Pump/Service and Repair)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming
P258B
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
Circuit/System Description
The engine control module (ECM) monitors the control circuit of the brake booster pump relay. The ECM supplies ground through the pump relay
control circuit which then supplies B+ voltage to actuate the brake booster pump. B+ voltage is supplied at all times to the coil side of the pump
relay.
Conditions for Running the DTC
P258A, P258C, P258D
Ignition ON.
P258B
* Engine Running
* Vacuum pump is activated for greater than 1.6 seconds.
Conditions for Setting the DTC
