For 1990-2009 cars

### Circuit Description

The supercharger (SC) intercooler coolant relay is a normally open relay. The relay armature is held in the open position by spring tension. 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 powertrain control module (PCM) 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 PCM 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 allows current to flow from the battery to the SC intercooler coolant pump. When the ignition switch is turned to the OFF position, power is interrupted to the ODM in the PCM, 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 SC intercooler coolant pump.

The SC intercooler coolant relay diagnosis is used to diagnose the load circuit supply voltage, the relay contacts, the relay load circuit which includes the SC intercooler coolant pump, and the ground for the SC intercooler coolant pump.

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: Power Distribution Schematics and Engine Controls Schematics Connector End View Reference: Power and Grounding Connector End Views , Electrical Center Identification Views , and Powertrain Control Module Connector End Views
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Turn OFF the ignition.
2. Inspect the coolant level in the reservoir that is used for the supercharger (SC) intercooler coolant pump system.

Is the SC intercooler cooling system coolant low?

Go to Cooling System Leak Testing and Charge Air Cooling System Draining and Filling

Go to Step 3

3 |

1. Turn ON the ignition, with the engine OFF.
2. Select the Intercooler Coolant Pump in the Engine Output Controls on the scan tool.
3. Command the relay ON and OFF with the scan tool.

Does the SC intercooler coolant pump turn ON and OFF?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 4

4 |

1. Remove the SC intercooler coolant pump relay.
2. Test for an intermittent and for poor connections at the underhood fuse block and for loose or damaged pins on the relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 15

Go to Step 5

5 | Probe the SC intercooler coolant pump relay load voltage supply circuit terminal in the fuse block with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 6 | Go to Step 10
6 | Use a 3-amp fused jumper wire to connect the SC intercooler coolant pump relay load voltage supply circuit terminal in the fuse block, to the SC intercooler coolant pump voltage supply circuit in the fuse block. Does the SC intercooler coolant pump turn ON? | Go to Step 13 | Go to Step 7
7 |

1. Leave the 3-amp fused jumper wire connected.
2. Disconnect the SC intercooler coolant pump.
3. Test for an intermittent and for poor and corroded connections at the SC intercooler coolant pump. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 15

Go to Step 8

8 | Probe the SC intercooler coolant pump voltage supply circuit terminal with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 9 | Go to Step 11
9 | Connect the test lamp between the SC intercooler coolant pump voltage supply circuit terminal and the SC intercooler coolant pump ground terminal. Does the test lamp illuminate? | Go to Step 14 | Go to Step 12
10 | Repair the high resistance or the open in the SC intercooler coolant pump relay load voltage supply circuit in the underhood fuse block. Refer to Circuit Testing and Wiring Repairs . Did you complete the repair? | Go to Step 15 | --
11 | Repair the high resistance or the open in the SC intercooler coolant pump voltage supply circuit. Refer to Circuit Testing and Wiring Repairs . Did you complete the repair? | Go to Step 15 | --
12 | Repair the high resistance or the open in the SC intercooler coolant pump ground circuit. Refer to Circuit Testing and Wiring Repairs . Did you complete the repair? | Go to Step 15 | --
13 | Replace the SC intercooler coolant pump relay. Did you complete the replacement? | Go to Step 15 | --
14 | Replace the SC intercooler coolant pump. Refer to Charge Air Cooler Coolant Pump Replacement . Did you complete the replacement? | Go to Step 15 | --
15 |

1. Turn the ignition OFF for 90 seconds.
2. Start the engine and operate the vehicle.
3. Observe the vehicle's performance and driveability.

Are there any vehicle symptoms that have not been diagnosed?

Go to Testing for Intermittent Conditions and Poor Connections and Symptoms - Engine Controls

System OK