2010 Cadillac Truck SRX FWD V6-3.0L Page 1529

2010 Cadillac Truck SRX FWD V6-3.0L Page 1529

* Cooling Fan Relay 2 and 3 Open Circuit Test Status

* Cooling Fan Relay 2 and 3 Low Voltage Test Status

* Cooling Fan Relay 2 and 3 High Voltage Test Status

2. Engine operating, observe the DTC information with a scan tool. DTC P0481 should not set.

3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the

conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

1. Ignition OFF, disconnect the KR20 cooling fan relays listed below:

* KR20A COOL FAN 2 Relay 9

* KR20D COOL FAN 1 Relay 13

2. Ignition ON, verify that a test lamp illuminates between ground and the COOL FAN 2 relay coil ignition circuit terminal 86.

瀚慖f the test lamp does not illuminate, test the relay coil ignition circuit for an open/high resistance.

Note: The following tests must be performed on each relay control circuit.

3. Connect the red lead of the DMM to a control circuit terminal listed below. Connect the black lead to ground. Set the DMM on the diode

setting. The DMM should display OL.

* KR20A COOL FAN 2 relay terminal 85

* KR20D COOL FAN 1 relay terminal 86

瀚慖f less than the specified range, test the relay coil control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.

Note: The following test must be performed on each relay control circuit.

4. Command the cooling fan relay ON and OFF at high speed, with a scan tool. The DMM should transition from OL when commanded OFF to

less than 1 V when commanded ON.

* KR20A COOL FAN 2 relay terminal 85

* KR20D COOL FAN 1 relay terminal 86

瀚慖f the circuit voltage does not correspond to the specified values, test the control circuit for an open/high resistance or for a short to

voltage. If the circuit tests normal, replace the K20 ECM.

5. If all circuits test normal, test or replace the appropriate KR20 relay.

Component Testing

1. Ignition OFF, disconnect the KR20 cooling fan relay.

2. Test for 60-100 ohm between terminals 85 and 86.

瀚慖f not within the specified range, replace the KR20 cooling fan relay.

3. Measure the resistance between the terminals listed below. The DMM should display OL.

* 30 and 86

* 30 and 87

* 30 and 85

* 85 and 87

瀚慖f less than the specified range, replace the KR20 cooling fan relay.

4. Connect a 20 A fused jumper wire between relay terminal 85 and B+. Connect a jumper wire between relay terminal 86 and ground. Test for

less than 2 ohm between terminals 30 and 87.

瀚慖f greater than the specified range, replace the KR20 cooling fan 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