The supercharger intercooler relay is a normally open relay. The relay armature is held in the open position by spring tension. The ignition 1 voltage is supplied directly to the relay coil and to the armature contact when the ignition is ON, or the engine is running. The engine control module (ECM) supplies the ground path to the relay coil control circuit via an internal integrated circuit called an output driver module (ODM). When the engine is running , the ECM commands the relay ON, and the relay coil creates an electromagnetic field. This electromagnetic field overcomes the spring tension and pulls the armature contact into the stationary contact of the relay load circuit. The closing of the relay contacts allow current to flow from the battery to the supercharger intercooler pump. When the ignition switch is turned to the OFF position, power is interrupted to the output driver module in the ECM and the relay electromagnetic field collapses. This allows the spring tension to separate the relay armature contact from the relay load circuit contact, which interrupts current flow to the supercharger intercooler pump.

If the ECM detects an improper voltage on the supercharger intercooler pump relay control circuit for more than 30 seconds, DTC P023A sets. Refer to Boost Control System Description for further information.

DTC P023A is a Type B DTC.

DTC P023A is a Type B DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Electrical Information Reference

DTC Type Reference

Scan Tool Reference

Special Tools Required

J 43244 Relay Puller Pliers

1. Ignition ON, command the CAC coolant pump relay ON and OFF several times with a scan tool. Listen and feel for the CAC coolant pump relay to click with each command.
2. Engine running, observe the DTC information with a scan tool. DTC P023A should not set.
3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the CAC coolant pump relay.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuit and ground.

⇒	If the test lamp illuminates, test the control circuit for a short to voltage.

3. Verify that a test lamp illuminates between the coil voltage supply circuit and ground.

⇒	If the test lamp does not illuminate, test the B+ coil supply circuit for a short to ground or an open/high resistance.

4. Verify that a test lamp illuminates between the B+ switch supply circuit and ground.

⇒	If the test lamp does not illuminate, test the B+ switch supply circuit for an open/high resistance. If the circuit tests normal and the B+ switch supply circuit fuse is open, test the CAC pump voltage supply circuit for a short to ground.

5. Disconnect the harness connector at the CAC coolant pump.
6. Test for less than 2 ohm of resistance between the CAC coolant pump ground circuit terminal 1 and ground.

⇒	If greater than the specified range, repair the ground circuit for an open/high resistance.

7. Connect the harness connector at the CAC coolant pump.
8. Connect a 10A fused jumper wire between the B+ switch circuit and the CAC coolant pump voltage supply circuit. Verify that CAC coolant pump is activated.

⇒	If the CAC coolant pump does not activate, test the CAC coolant voltage supply circuit for an open/high resistance. If the circuit tests normal, test the CAC coolant pump motor. Refer to Component Testing.

9. Connect a test lamp between the B+ coil supply circuit and the CAC relay control circuit.
10. Command the CAC coolant pump ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between commanded states.

⇒	If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.

⇒	If the test lamp is always OFF, test the control circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

11. If all circuits test normal, test the CAC coolant pump relay. Refer to Component Testing.

Coolant Pump Relay

1. Ignition OFF, disconnect the CAC coolant pump relay.
2. Test between the normally-closed switch terminals, if any, for 0 ohms.
3. Test between the normally-open switch terminals for infinite ohms.
4. Test between each switch terminal and either coil terminal for infinite ohms.
5. Connect the relay coil terminals to ground and fused power to energize the relay.
6. Test between each switch terminal and each coil terminal for 0 volts.
7. Test between the normally-closed switch terminals, if any, for infinite ohms.
8. Test between the normally-open switch terminals for 0 ohms.

⇒	If the relay fails any of the above tests, replace the relay.

CAC Pump Dynamic Test

1. Install a 10A fused jumper wire between the B+ terminal 2 and 12 volts.
2. Install a jumper wire between the ground terminal 1 and ground.
3. Observe for the CAC pump to activate.

⇒	If the CAC pump does not activate, replace the CAC pump

Perform the Diagnostic Repair Verification after completing the repair.