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Supercharger Coolant Pump Relay: Testing and Inspection




Supercharger Intercooler Relay Diagnosis

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information






Circuit Description

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. 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 charge air cooler coolant pump.

Diagnostic Aids

When disconnecting electrical connectors or removing fuses and relays from a fuse block, inspect the component electrical terminals for corrosion and the mating electrical terminals for correct tension.

Reference Information

Schematic Reference

Engine Cooling Schematics [1][2]Cooling System

Connector End View Reference

Component Connector End Views Fuel Pump and Level Sensor Assembly - Primary

Description and Operation

* Supercharger Description and Operation Supercharger

* Boost Control System Description Description and Operation

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

* Electrical Center Identification Views X50A Fuse Block - Underhood Label (North America)

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON.

2. Verify that DTC P023A is not set.

• If the DTC is set
Refer to DTC P023A P023A

• If the DTC is not set

3. Verify the KR18 charge air cooler coolant pump relay clicks and the M10 charge air cooler coolant pump turns ON and OFF when commanding the Charge Air Cooler Coolant Pump ON and OFF with a scan tool.

• If the relay does not click or the pump does not turn ON and OFF
Refer to Circuit/System Testing

• If the relay clicks and the pump turns ON and OFF

4. All OK

Circuit/System Testing

1. Ignition OFF, disconnect the KR18 charge air cooler coolant pump relay. Ignition ON.

2. Verify a test lamp illuminates between the relay switch B+ circuit terminal 30 and ground.

• If the test lamp does not illuminate
Replace the accessory wiring junction block. Refer to Accessory Wiring Junction Block Replacement Removal and Replacement.

• If the test lamp illuminates

3. Verify a test lamp does not illuminate between the relay switch B+ circuit terminal 87 and ground.

• If the test lamp illuminates
Repair the short to voltage on the circuit.

• If the test lamp does not illuminate

4. Connect the KR18 charge air cooler coolant pump relay.

5. Ignition OFF. Disconnect the harness connector at the M10 charge air cooler coolant pump.

6. Test for less than 10 ohms between the M10 charge air cooler coolant pump ground circuit terminal 4 and ground.

• If 10 ohms or greater

1. Ignition OFF.

2. Test for less than 2 ohms in the ground circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, repair the open/high resistance in the ground connection.

• If less than 10 ohms

7. Ignition ON, connect a test lamp between the charge air motor voltage circuit terminal 5 and ground.

8. Verify the test lamp turns ON and OFF when commanding the Charge Air Cooler Coolant Pump ON and OFF with a scan tool.

• If the test lamp is always OFF and the circuit fuse is good

1. Ignition OFF

2. Test for less than 2 ohms in the circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, test or replace the KR18 charge air cooler coolant pump relay

• If the test lamp is always OFF and the circuit fuse is open

1. Ignition OFF, replace the fuse.

2. Test for infinite resistance between the voltage circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance, test or replace the M10 charge air cooler coolant pump.

• If the test lamp is always ON

1. Ignition ON

2. Test for less than 1 V between the circuit and ground.

• If 1 V or greater, repair the short to voltage on the circuit.

• If less than 1 V, Test or replace the KR18 charge air cooler coolant pump relay.

• If the test lamp turns ON and OFF

9. Connect a test lamp between the logic circuit terminal 1 and ground.

10. Verify the test lamp illuminates when commanding the Charge Air Cooler Coolant Pump ON with a scan tool.

• If the test lamp does not illuminate

1. Ignition OFF

2. Test for less than 2 ohms in the circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If the test lamp illuminates

11. Test or replace the M10 charge air cooler coolant pump.

Component Testing

Coolant Pump Relay

1. Ignition OFF, disconnect the KR18 charge air cooler coolant pump relay.

2. Test for 90-125 ohms between terminals 85 and 86.

• If less than 90 ohms or greater than 125 ohms
Replace the KR18 charge air cooler coolant pump relay.

• If between 90-125 ohms

3. Test for infinite resistance between the terminals listed below:

* 30 and 86

* 30 and 87

* 30 and 85

* 85 and 87

• If less than infinite resistance
Replace the KR18 charge air cooler coolant pump relay.

• If infinite resistance

4. Install a 10 A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground.

5. Test for less than 2 ohms between terminals 30 and 87.

• If 2 ohms or greater
Replace the KR18 charge air cooler coolant pump relay.

• If less than 2 ohms

6. All OK

Charge Air Cooler Coolant Pump Dynamic Test

1. Ignition ON.

2. Install a jumper wire between the B+ terminal 5 and the logic circuit terminal 1. Install a 10 A fused jumper wire between the B+ circuit terminal 5 and 12 V. Install a jumper wire between the ground circuit terminal 4 and ground.

3. Verify the M10 charge air cooler coolant pump activates.

• If the M10 charge air cooler coolant pump does not activate
Replace the M10 charge air cooler coolant pump.

• If the M10 charge air cooler coolant pump activates

4. All OK

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Relay Replacement (Within an Electrical Center) Relay Replacement (Within an Electrical Center)Relay Replacement (Attached to Wire Harness) Relay Replacement (Attached to Wire Harness)

* Charge Air Cooler Coolant Pump Replacement (LSA) Service and Repair

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