Engine Cooling System Cadillac ATS I

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON.
Verify the scan tool Radiator Coolant Temperature Sensor parameter is between -39 to + 120°C (-38 to +248°F) and changes with engine run time. If not between -39 to + 120°C (-38 to +248°F) or does not change Refer to Circuit/System Testing. If between -39 to + 120°C (-38 to +248°F) and changes
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.
Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
All OK.

Circuit/System Testing

Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B34B Engine Coolant Temperature Sensor. It may take up to 2 minutes for all vehicle systems to power down.
Test for less than 5 ohms between the low reference terminal 2 and ground. If 5 ohms or greater Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for less than 2 ohms in the low reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If less than 5 ohms
Ignition ON.
Verify the scan tool Radiator Coolant Temperature Sensor parameter is colder than -39°C (-38°F). If warmer than -39°C (-38°F) Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the signal circuit terminal 1 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K20 Engine Control Module. If colder than -39°C (-38°F)
Install a 3 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2.
Verify the scan tool Radiator Coolant Temperature Sensor parameter is warmer than 149°C (300°F). If colder than the 149°C (300°F) Ignition OFF, remove the jumper wire, disconnect the harness connector at the K20 Engine Control Module, Ignition ON. Test for less than 1 V between the signal circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Ignition OFF. Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If warmer than 149°C (300°F)
Test or replace the B34B Engine Coolant Temperature Sensor.

Component Testing

Ignition OFF, disconnect the harness connector at the B34 Engine Coolant Temperature Sensor.
Test the RCT sensor by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the «Temperature Versus Resistance»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__temperature-versus-resistance) table. The resistance values should be in range of the table values. If not within the specified range Replace the B34 Engine Coolant Temperature Sensor. If within the specified range
Test for infinite resistance between each terminal and the sensor housing. If less than infinite resistance Replace the B34 Engine Coolant Temperature Sensor. If infinite resistance
All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Engine Coolant Temperature Sensor Replacement - Radiator»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) for radiator coolant temperature sensor replacement.
«Engine Control Module Replacement (LCV)»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-20l-ltg-or-25l-lcv-repair-instructions) , «Engine Control Module Replacement (LTG)»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-20l-ltg-or-25l-lcv-repair-instructions) for engine control module replacement, programming, and setup.

Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Radiator Coolant Temperature Sensor Signal	P00B3	P00B4	P00B4*	P112F
Low Reference		P00B4	P00B4*	P112F
* Internal ECM or sensor damage may occur if the circuit is shorted to B+.

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Engine Running in Closed Loop Parameter Normal Range: Varies with ambient temperature
Radiator Coolant Temperature Sensor Signal	150°C (302°F)	40°C (-40°F)	40°C (-40°F)*
Low Reference		40°C (-40°F)	40°C (-40°F)*
* Internal ECM or sensor damage may occur if the circuit is shorted to B+.

Radiator Coolant Temperature Sensor

Circuit Description

The engine control module (ECM) monitors the temperature of the engine radiator coolant. The ECM controls the thermostat with a pulse width modulated (PWM) signal. The ECM compares the radiator coolant temperature to the engine coolant temperature in order to determine if there sufficient coolant flow through the thermostat.

DTCs P00B3, P00B4, P0117, P0118, P111E, and P112F are not set.
The engine run time is greater than 5 m.
The engine coolant temperature is warmer than 99°C (210°F).
The DTC runs continuously when the above conditions are met.

Note. The scan tool display range is between -40 and + 150°C (-40 and +302°F).

The ECM detects the difference between the RCT sensor and the ECT sensor is greater than 30°C (86°F) when the ECT sensor is warmer than 117°C (243°F) for greater than 30 s.

DTC P00B7 is a Type B DTC.

The thermostat has a mechanical fail-safe in case of an electrical condition with the thermostat heater. The mechanical thermostat will start to open at approximately 97°C (207°F).
A resistance condition in the RCT sensor circuits may cause this DTC. This condition results in a greater voltage on the RCT sensor signal circuit, which is interpreted by the ECM as a colder RCT.

Schematic Reference

Engine Controls Schematics (LTG) , Engine Controls Schematics (LCV)

Connector End View Reference

Cooling System Description and Operation

Description and Operation

Electrical Information Reference

«Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Ignition ON.
Verify that DTC P00B3, P00B4, P0117, P0118, P0480, P0481, P0597, P0598, P0599, P111E, or P112F are not set. If DTC P00B3, P00B4, P0117, P0118, P0480, P0481, P0597, P0598, P0599, P111E, or P112F are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If DTC P00B3, P00B4, P0117, P0118, P0480, P0481, P0597, P0598, P0599, P111E, or P112F are not set
Verify the coolant in the radiator surge tank is at the correct level and there are no engine coolant leaks. If the coolant in the radiator surge tank is not at the correct level or there are engine coolant leaks Refer to «Cooling System Draining and Filling (Static Fill)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-static) , «Cooling System Draining and Filling (GE 47716)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-ge) , and «Loss of Coolant»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant) . If the coolant in the radiator surge tank is at the correct level and there are no engine coolant leaks
Verify the engine cooling fan operates. If the engine cooling fan does not operate Refer to «Cooling Fan Inoperative»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) , «Cooling Fan Inoperative (LTG w/V03 or Manual Transmission)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) . If the engine cooling fan operates
Engine idling for 15 min with the A/C OFF.
Command the Engine Coolant Thermostat Heater to 100 % with a scan tool. Increase the engine speed to 3,000 RPM. Observe the scan tool ECT sensor parameter. The temperature should decrease to less than 85°C (185°F). If ECT is warmer than 85°C (185°F) Refer to Circuit/System Testing. If ECT is colder than 85°C (185°F)
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.
Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
All OK.

Vehicle OFF, inspect the cooling system for the conditions below. Refer to «Symptoms - Engine Cooling»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) . Weak coolant solution Obstructed radiator air flow or bent radiator fins Blocked cooling system passages Radiator hoses that are restricted, collapsed, or deteriorated Damaged water pump and or belt Loss of cooling system pressure Leaking surge tank cap Radiator hoses Cylinder head or an engine block that is cracked or plugged If a condition was found Repair as necessary. If a condition was not found
Replace the Engine Coolant Thermostat.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Engine Coolant Thermostat Housing Replacement (LFX) , Engine Coolant Thermostat Housing Replacement (LCV) , Engine Coolant Thermostat Housing Replacement (LTG)

Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Cooling Fan Control Module B+ Supply	P0480, P0691*	P0480
Cooling Fan Control Module Ground
Cooling Fan Control Module Control	P0691	P0480	P0692
*Opens cooling fan fuse.

The engine cooling fan system is composed of one electric cooling fan and a cooling fan control module. The engine control module (ECM) controls the fan speed by sending a pulse width modulated (PWM) signal to the cooling fan control module. The cooling fan control module varies the voltage drop across the cooling fan motor in relation to the pulse width modulated signal, which enables cooling fan operation at variable speeds. The ECM will only operate the cooling fan at certain percentages to prevent undesirable noise and vibration. The cooling fan control module is thermally protected to prevent module damage in the case of a short circuit condition in the cooling fan motor.

The ignition voltage is greater than 11 volts.
The DTCs run continuously once the above conditions are met.

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 5 seconds.

DTCs P0480, P0691, and P0692 are Type B DTCs.

The cooling fan will not operate when the scan tool Cooling Fan Motor Command parameter displays less than 4 %. This is a normal condition.
A delay or ramp up of approximately 12 seconds may occur before the cooling fan activates or changes speed when being commanded with a scan tool.
The cooling fan Control Function operates as described below when the ignition is ON, and engine is OFF: Command State 1 operates the cooling fan at approximately 18-21 % Command State 2 operates the cooling fan at approximately 54 % Command State 3 operates the cooling fan at approximately 67 % Command State 4 operates the cooling fan at approximately 85 % Command State 5 operates the cooling fan at approximately 90 %
During normal operating conditions the ECM may initially activate the cooling fan at 4 or 5 % and then increase to the percentages indicated above, as needed, to satisfy powertrain cooling requirements. Generally, the ECM will operate the cooling fan at the specified percentages but, may scale the percentages either higher or lower in response to generator demand.
When operating the cooling fan with a scan tool, the Commanded States 1-5 should be exercised in order, from OFF to High or High to OFF. The cooling fan control module may disable the cooling fan if a Commanded State is skipped.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON.
Verify the G10 Cooling Fan Motor activates in each available speed when commanding the cooling fan ON with a scan tool. The cooling fan speed should increase with each command. The cooling fan does not activate or increase in speed as commanded Refer to Circuit/System Testing The cooling fan activates and increases in speed as commanded
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.
Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing If the DTC does not set
All OK.

Ignition OFF, disconnect the harness connector X1 at the K22 Cooling Fan Control Module, ignition ON.
Verify that a test lamp illuminates between the B+ circuit terminal 2 and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF, and all vehicle systems OFF, it may take up to 2 minutes for all vehicle systems to power down. Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF, and all vehicle systems OFF, it may take up to 2 minutes for all vehicle systems to power down. Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground in the circuit. If infinite resistance, replace the K22 Cooling Fan Control Module. If the test lamp illuminates
Connect a DMM, set on the diode setting, between the control circuit terminal X1-4 and ground.
Verify the DMM reading is greater than 2.5 V or displays O.L. with the cooling fan commanded OFF. If 2.5 V or less Ignition OFF, and all vehicle systems OFF, it may take up to 2 minutes for all vehicle systems to power down. Disconnect the harness connector X1 at the K20 Engine Control Module. Test for infinite resistance between the K22 Cooling Fan Control Module control circuit terminal X1-4 and ground. If less than infinite resistance, repair the short to ground in the circuit. If infinite resistance, replace the K20 Engine Control Module. If greater than 2.5 V or displays O.L.
Command the cooling fan ON with a scan tool using Command State 5.
Verify the DMM reading is less than 1 V. If 1 V or greater Ignition OFF. Disconnect the harness connector X1 at the K20 Engine Control Module, ignition ON. Test for less than 1 V between the K22 Cooling Fan Control Module control circuit terminal X1-4 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V. Ignition OFF, and all vehicle systems OFF, it may take up to 2 minutes for all vehicle systems to power down. Test for less than 2 ohms in the circuit between the K22 Cooling Fan Control Module terminal X1-4 and the K20 Engine Control Module terminal X1-59. If 2 ohms or greater, repair the open in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If less than 1 V
Replace the K22 Cooling Fan Control Module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Fan Control Module Replacement (LCV, LFX without KC4, LTG without V03)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system)
«Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Cooling Fan Control Module B+ Supply	P0480, P0691*	P0480
Cooling Fan Control Module Ground
Cooling Fan Control Module Control	P0691	P0480	P0692
*Opens cooling fan fuse.

The ignition voltage is greater than 11 volts.
The DTCs run continuously once the above conditions are met.

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 5 seconds.

DTCs P0480, P0691, and P0692 are Type B DTCs.

The cooling fan will not operate when the scan tool Cooling Fan Motor Command parameter displays less than 4 %. This is a normal condition.
A delay or ramp up of approximately 12 seconds may occur before the cooling fan activates or changes speed when being commanded with a scan tool.
The cooling fan Control Function operates as described below when the ignition is ON, and engine is OFF: Command State 1 operates the cooling fan at approximately 18-21 % Command State 2 operates the cooling fan at approximately 54 % Command State 3 operates the cooling fan at approximately 67 % Command State 4 operates the cooling fan at approximately 85 % Command State 5 operates the cooling fan at approximately 90 %
During normal operating conditions the ECM may initially activate the cooling fan at 4 or 5 % and then increase to the percentages indicated above, as needed, to satisfy powertrain cooling requirements. Generally, the ECM will operate the cooling fan at the specified percentages but, may scale the percentages either higher or lower in response to generator demand.
When operating the cooling fan with a scan tool, the Commanded States 1-5 should be exercised in order, from OFF to High or High to OFF. The cooling fan control module may disable the cooling fan if a Commanded State is skipped.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON.
Verify the G10 Cooling Fan Motor activates in each available speed when commanding the cooling fan ON with a scan tool. The cooling fan speed should increase with each command. The cooling fan does not activate or increase in speed as commanded Refer to Circuit/System Testing The cooling fan activates and increases in speed as commanded
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.
Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing If the DTC does not set
All OK.

Ignition OFF, disconnect the harness connector at the G10 Cooling Fan Motor, ignition ON.
Verify that a test lamp illuminates between the B+ circuit terminal 1and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF, and all vehicle systems OFF, it may take up to 2 minutes for all vehicle systems to power down. Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF, and all vehicle systems OFF, it may take up to 2 minutes for all vehicle systems to power down. Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground in the circuit. If infinite resistance, replace the K22 Cooling Fan Control Module. If the test lamp illuminates
Connect a DMM, set on the diode setting, between the control circuit terminal 3 and ground.
Verify the DMM reading is greater than 2.5 V or displays O.L. with the cooling fan commanded OFF. If 2.5 V or less Ignition OFF, and all vehicle systems OFF, it may take up to 2 minutes for all vehicle systems to power down. Disconnect the harness connector X1 at the K20 Engine Control Module. Test for infinite resistance between the G10 Cooling Fan Motor control circuit terminal 3 and ground. If less than infinite resistance, repair the short to ground in the circuit. If infinite resistance, replace the K20 Engine Control Module. If greater than 2.5 V or displays O.L.
Command the cooling fan ON with a scan tool using Command State 5.
Verify the DMM reading is less than 1 V. If 1 V or greater Ignition OFF. Disconnect the harness connector X1 at the K20 Engine Control Module, ignition ON. Test for less than 1 V between the G10 Cooling Fan Motor control circuit terminal 3 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V. Ignition OFF, and all vehicle systems OFF, it may take up to 2 minutes for all vehicle systems to power down. Test for less than 2 ohms in the circuit between the G10 Cooling Fan Motor terminal 3 and the K20 Engine Control Module terminal X1-59. If 2 ohms or greater, repair the open in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If less than 1 V
Replace the K20 Cooling Fan Control Module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Engine Coolant Fan Shroud Replacement (LTG with VO3)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) for G10 Cooling Fan Motor replacement.
«Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage
Voltage	P0031, P0443, P0597, P0598*, P06DA, P06DB	P0031, P0443, P0597, P0598, P06DA, P06DB
Thermostat Control Circuit	P0598	P0597	P0599, P0690
*Opens the fuse that supplies voltage to the engine coolant thermostat

The engine control module (ECM) controls the pulse width modulated (PWM) thermostat. The thermostat controls coolant flow and regulates the engine operating temperature. Ignition voltage is supplied directly to the thermostat through a fuse. The ECM controls the thermostat by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback circuit that is pulled-up to a voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.

Conditions for Running the DTCs

The ignition is ON, or the engine is running.
The DTCs run continuously once the above condition is met

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 15 seconds.

DTCs P0597, P0598, and P0599 are Type B DTCs.
The engine control module commands the engine cooling fans ON.

Conditions for Clearing the DTC

DTCs P0597, P0598, and P0599 are Type B DTCs.

A low engine coolant level could cause the thermostat heater to overheat and set a DTC.
The thermostat has a mechanical fail-safe in case of an electrical condition with the thermostat heater. The mechanical thermostat will open at approximately 80°C (176°F). The mechanical thermostat will cycle from approximately 85°C (185°F) to approximately 102°C (215°F).

Schematic Reference

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Verify the coolant in the radiator surge tank is at the correct level and there are no engine coolant leaks. «Loss of Coolant»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant) , and «Cooling System Draining and Filling (Static Fill)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-static) , «Cooling System Draining and Filling (GE 47716)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-ge) If the coolant level is not correct Repair as necessary If the coolant level is correct
Ignition ON
Verify the parameters listed below do not display Malfunction when commanding the Engine Coolant Thermostat Heater ON and OFF with a scan tool. Engine Coolant Thermostat Heater Control Circuit Low Voltage Test Status Engine Coolant Thermostat Heater Control Circuit Open Test Status Engine Coolant Thermostat Heater Control Circuit High Voltage Test Status If Malfunction is displayed Refer to Circuit/System Testing. If Malfunction is not displayed
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.
Verify the DTC does not set. If any DTC sets Refer to Circuit/System Testing. If the DTC does not set
All OK.

Ignition OFF, disconnect the harness connector at the E41 Engine Coolant Thermostat Heater, Ignition ON.
Verify that a test lamp illuminates between the ignition circuit terminal 1 and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF . Test for less than 2 ohms in the ignition circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF . Test for infinite resistance between the ignition circuit and ground. If less than infinite resistance, repair the short to ground in the circuit. If infinite resistance, test all the components connected to fuse and replace as necessary. If the test lamp illuminates
Connect a test lamp between the ignition circuit terminal 1 and the control circuit terminal 2, command the Engine Coolant Thermostat Heater to Increase to 100 % and Decrease to 0 % with a scan tool.
Verify that a test lamp turns On and OFF. If the test is always ON Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K20 Engine Control Module. If the test lamp is always OFF Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON. Test for less than 1 V between the control circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V. Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms replace the K20 Engine Control Module If the test lamp turns On and OFF
Test or replace the E41 Engine Coolant Thermostat Heater.

Perform the Diagnostic Repair Verification after completing the repair.

«Engine Coolant Thermostat Housing Replacement (LFX)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) , «Engine Coolant Thermostat Housing Replacement (LCV)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) , «Engine Coolant Thermostat Housing Replacement (LTG)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) for E41 engine coolant thermostat heater replacement.
«Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) engine control module replacement, programming, and setup.

Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Signal	P00B3	P00B4	P00B4*	P112F
Low Reference		P00B4	P00B4*	P112F
* Internal ECM or sensor damage may occur if the circuit is shorted to B+.

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Engine Running in Closed Loop Parameter Normal Range: Varies with ambient temperature
Signal	140°C (284°F)	40°C (-40°F)	40°C (-40°F)*
Low Reference		40°C (-40°F)	40°C (-40°F)*
* Internal ECM or sensor damage may occur if the circuit is shorted to B+.

Radiator Coolant Temperature Sensor

The engine coolant radiator temperature sensor is a variable resistor that measures the temperature of the engine coolant in the radiator. The engine control module (ECM) supplies 5 volts to the engine coolant radiator temperature signal circuit and supplies a ground to the low reference circuit. The purpose of this diagnostic is to determine if the input from the RCT sensor is skewed warmer than normal. The internal clock of the ECM will record the amount of time the engine is OFF. If the required engine OFF time is met at start-up, the ECM will compare the temperature difference between the actual measured RCT and ECT sensors.

The following table illustrates the difference between temperature, resistance, and voltage

RCT	RCT Resistance	RCT Signal Voltage
Cold	High	High
Warm	Low	Low

DTCs P00B3, P00B4, P0112, P0113, P0117, P0118, P0502, P0503, P111E or P2610 are not set.
The vehicle has been OFF for greater than 8 hours before vehicle ON.
The engine is running.
The intake air temperature (IAT) is warmer than -7°C (19°F).
The fuel level is greater than 10 percent.
The DTC runs once per ignition cycle when the above conditions are met.

The ECM determines the absolute difference of temperature between the RCT start up temperature and ECT start up temperature is greater than 20°C (68°F) .

DTC P112F is a Type B DTC.

As the thermostat opens, the radiator coolant temperature sensor signal should rise steadily, then stabilize once the thermostat opens completely.
Inspect for the correct operation of the engine cooling system and verify the correct coolant level.

Schematic Reference

Engine Controls Schematics (LTG) , Engine Controls Schematics (LCV)

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON.
Verify the scan tool Radiator Coolant Temperature Sensor parameter is between -39 to + 120°C (-38 to +248°F) and changes with engine run time. If not between -39 to + 120°C (-38 to +248°F) or does not change Refer to Circuit/System Testing. If between -39 to + 120°C (-38 to +248°F) and changes
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.
Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
All OK.

Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B34B Engine Coolant Temperature Sensor 2. It may take up to 2 minutes for all vehicle systems to power down.
Test for less than 5 ohms between the low reference terminal 2 and ground. If 5 ohms or greater Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for less than 2 ohms in the low reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If less than 5 ohms
Ignition ON.
Verify the scan tool Radiator Coolant Temperature Sensor parameter is colder than -39°C (-38°F). If warmer than -39°C (-38°F) Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the signal circuit terminal 1 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K20 Engine Control Module. If colder than -39°C (-38°F)
Install a 3 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2.
Ignition ON, Verify the scan tool Radiator Coolant Temperature Sensor parameter is warmer than 140°C (284°F). If colder than the 140°C (284°F) Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, Ignition ON. Test for less than 1 V between the signal circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Ignition OFF Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If warmer than 140°C (284°F)
Test or replace the B34B Engine Coolant Temperature Sensor 2.

Vehicle OFF, remove the B34B Engine Coolant Temperature Sensor.
Test the engine coolant temperature sensor by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the «Temperature Versus Resistance»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__temperature-versus-resistance) table and verify that the resistance is within 5 percent of the specification. If not within the specified range, replace the B34B Engine Coolant Temperature Sensor.

Perform the Diagnostic Repair Verification after completing the repair.

«Engine Coolant Temperature Sensor Replacement - Radiator»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system)
«Engine Control Module Replacement (LCV)»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-20l-ltg-or-25l-lcv-repair-instructions) , «Engine Control Module Replacement (LTG)»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-20l-ltg-or-25l-lcv-repair-instructions) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) uses the engine coolant temperature sensor to monitor the engine for an over-temperature condition. This condition occurs when the coolant temperature is above a calibrated value. The ECM will alternately disable 2 groups of cylinders by turning OFF the fuel injectors. By switching between the 2 groups of cylinders, the ECM is able to reduce the temperature of the coolant.

The engine is operating for greater than 30 seconds.
DTC P1258 runs continuously once the conditions above have been met.

The ECM detects that engine coolant temperature is warmer than 132°C (270°F) for 2 seconds or greater.

DTC P1258 is a Type A DTC.
The engine will operate in the Overheated Engine Protection Operating Mode.
The IP will illuminate the coolant temperature indicator lamp and the driver information center (DIC), if equipped, may display a message.
If the protection mode is active and an ECT sensor DTC sets, the protection mode will remain active at the start of the next drive cycle until the ECT sensor DTC runs and passes.

DTC P1258 is a Type A DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Cooling Fan Description and Operation»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system)
«Instrument Cluster Description and Operation»(/cadillac/ats/i-2012-2014/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)
«Indicator/Warning Message Description and Operation»(/cadillac/ats/i-2012-2014/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)

DTC Type Reference

Scan Tool Reference

K20 Engine Control Module: Scan Tool Information (LFW, LFX or LTG) , K20 Engine Control Module: Scan Tool Information (LCV) for scan tool information

Ignition ON.
Verify DTC P0480, P0691, or P0692 is not set. If a DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If no DTCs is set
Verify the cooling fan operates at each available speed as commanded with a scan tool. Cooling fan does not operate Refer to «Cooling Fan Inoperative»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) , «Cooling Fan Inoperative (LTG w/V03 or Manual Transmission)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) . Cooling fan operates
Verify that the engine does not overheat. Engine overheats Refer to «Engine Overheating»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__engine-overheating) . Engine does not overheat
Operate the vehicle within the conditions that the customer experienced and verify the DTC does not set. If the DTC sets Refer to «Symptoms - Engine Cooling»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) . If the DTC does not set
All OK

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) monitors temperature difference between the engine coolant temperature (ECT) sensor and the radiator coolant temperature (RCT) sensor during a cold start-up. The purpose of this diagnostic is to analyze the engine coolant thermostat for being stuck open.

DTCs P00B3, P00B4, P0101, P0102, P0103, P0111, P0112, P0113, P0114, P0117 , P0118, P111E or P112F are not set.
The vehicle has had a minimum ignition OFF time of 7 h.
The engine run time is between 90 s and 30 min.
The engine coolant temperature (ECT) sensor at start-up is between -10° C to 75° C (14° F to 167° F).
The intake air temperature (IAT) sensor is between -7° C to 52° C (19° F to 126° F).
The Engine Coolant Thermostat Heater Command is less than 20 %.
The airflow into the engine is between 8 to 30 g/s.
The Ethanol in the fuel is less than 87 %.
The DTC runs once per ignition cycle when the above conditions are met.

The ECM detects the engine coolant thermostat is stuck open for at least 90 s.

DTC P2181 is a Type B DTC

Insufficient vehicle interior heating is an indication of improper thermostat operation.
The scan tool Desired ECT Sensor and the ECT Sensor parameters should be within 5° C (41° F) when the engine is at operating temperature.
A resistance condition in the ECT sensor circuits may cause this DTC. This condition results in a greater voltage on the ECT sensor signal circuit, which is interpreted by the ECM as a colder ECT.

Schematic Reference

Engine Controls Schematics (LTG) , Engine Controls Schematics (LCV)

Connector End View Reference

Cooling System Description and Operation

Description and Operation

Electrical Information Reference

«Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Engine running, observe the DTC information with a scan tool. DTC P00B3, P00B4, P0101, P0102, P0103, P0111, P0112, P0113, P0114, P0117 , P0118, P111E or P112F should not be set. If DTC P00B3, P00B4, P0101, P0102, P0103, P0111, P0112, P0113, P0114, P0117 , P0118, P111E or P112F is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If DTC P00B3, P00B4, P0101, P0102, P0103, P0111, P0112, P0113, P0114, P0117 , P0118, P111E or P112F is not set
Verify the coolant in the radiator surge tank is at the correct level and there are no engine coolant leaks. If the coolant in the radiator surge tank is not at the correct level or there are engine coolant leaks Refer to «Cooling System Draining and Filling (Static Fill)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-static) , «Cooling System Draining and Filling (GE 47716)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-ge) , and «Loss of Coolant»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant) . If the coolant in the radiator surge tank is at the correct level and there are no engine coolant leaks
Verify the engine cooling fan is not ON at all times. If the engine cooling fan is ON at all times Refer to «Cooling Fan Always On»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) , «Cooling Fan Always On (LTG w/V03 or Manual Transmission)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) . If the engine cooling is not ON at all times
Engine idling for 15 min with the A/C OFF.
Command the Engine Coolant Thermostat Heater to 0 % with a scan tool. Increase the engine speed to 3,000 RPM. Observe the scan tool ECT sensor parameter for 5 min or until the ECT sensor is between 82° C and 102° C (180° F and 215° F) If ECT sensor is not between 82° C and 102° C (180° F and 215° F) Replace the engine coolant thermostat. If ECT sensor is between 82° C and 102° C (180° F and 215° F)
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.
Verify the DTC does not set. If the DTC sets Refer to step 1. If the DTC does not set
All OK.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Engine Coolant Thermostat Housing Replacement (LFX) , Engine Coolant Thermostat Housing Replacement (LCV) , Engine Coolant Thermostat Housing Replacement (LTG) for Engine Coolant Thermostat Replacement.

Important Preliminary Inspections Before Starting

Before using the Symptom diagnosis, perform the following

Perform «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) and verify all of the following items: Engine control module (ECM) and malfunction indicator lamp (MIL) are operating correctly. There are no diagnostic trouble codes (DTCs) stored. Scan tool data is within a normal operating range.
Verify the customer concern.
Perform the Visual/Physical Inspection in this section. The visual/physical inspection is extremely important, and can lead to correcting a condition without additional testing. It may also help reveal the cause of an intermittent condition.
Locate the correct symptom. Perform the tests and inspections associated with the symptom.

Review the entire cooling system operation in order to familiarize yourself with the system functions. Refer to Cooling Fan Description and Operation , and Cooling System Description and Operation .

Visual/Physical Inspection

CAUTION

Use the connector test adapter kit EL-35616-F for any test that requires probing the following items: The control module harness connectors The electrical center fuse/relay cavities The component terminals The component harness connector Using this kit will prevent damage caused by the improper probing of connector terminals.

Several of the symptom procedures call for a careful visual and physical inspection. This can lead to correcting a condition without further tests and can save time. This inspection should include the following

Ensure that the control module grounds are clean, tight, and correctly located.
Inspect cooling system hoses and pipes for splits, kinks, and improper connections. Inspect thoroughly for any type of leak or restriction.
Inspect for a dirty or restricted radiator or HVAC condenser.
Inspect for aftermarket devices which could affect the operation of the cooling system.
Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
Inspect the coolant recovery reservoir for proper coolant level.

Identifying Intermittent Conditions

Many intermittent conditions occur with harness or connector movement due to engine torque, rough pavement, vibration or physical movement of a component. Refer to the following for a list to help isolate an intermittent condition

Water intrusion in connectors, terminals, or components
Poor connector mating
Terminal contact
High circuit or component resistance-High resistance can include any resistance, regardless of the amount, which can interrupt the operation of the component.
Harness' that are routed too tight, or chaffed circuits
High or low ambient temperatures
High or low engine coolant temperatures
High underhood temperatures
Heat build up in components or circuits due to circuit resistance, poor terminal contact, or high electrical load
High or low system voltage
High vehicle load conditions
Rough road surface
Electro-magnetic interference (EMI)/circuit interference from relays, solenoids or other electrical surge
Incorrect installation of non-factory, aftermarket, or after factory add on accessories

If an intermittent fault is detected, refer to Testing for Intermittent Conditions and Poor Connections for specific strategies in diagnosing intermittent conditions.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

«Cooling Fan Always On»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) , «Cooling Fan Always On (LTG w/V03 or Manual Transmission)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system)
«Cooling Fan Inoperative»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) , «Cooling Fan Inoperative (LTG w/V03 or Manual Transmission)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system)
«Engine Overheating»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__engine-overheating)
«Loss of Coolant»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant)
«Thermostat Diagnosis»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__thermostat-diagnosis)
«Engine Fails To Reach Normal Operating Temperature»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__engine-fails-to-reach-normal-operating)

Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Certain resistance conditions with IAT or ECT sensors may cause unwarranted cooling fan activation. If the ECM is commanding the cooling fan ON for no apparent reason and without any component or system DTCs set, the IAT or ECT sensor may be skewed. If this condition is suspected, refer to the temperature versus resistance tables in the appropriate engine controls subsection.
The cooling fan will not operate when the scan tool Cooling Fan Motor Command parameter displays less than 4 %. This is a normal condition.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

«Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON.
Verify that DTC P0480, P0691, or P0692, is not set. If a DTC is set Refer to «DTC P0480, P0691, or P0692»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) , «DTC P0480, P0691, or P0692 (LTG w/V03 or Manual Transmission)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) . If no DTC is set.
Verify the scan tool Cooling Fan Motor Command parameter is less than 4 %. If 4 % or greater Refer to Diagnostic Aids and «Symptoms - Engine Cooling»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) for further diagnosis. If less than 4 %
Verify that the G10 Cooling Fan Motor is not operating. If the G10 Cooling Fan Motor is operating Refer to Circuit/System Testing. If the G10 Cooling Fan Motor is not operating
All OK.

Ignition OFF.
Disconnect the G10 Cooling Fan Motor harness connector X2 at the K22 Cooling Fan Control Module, ignition ON.
Verify that the G10 Cooling Fan Motor is not operating. If the G10 Cooling Fan Motor is operating Ignition ON. Test for less than 1 V between the G10 Cooling Fan Motor harness connector terminal 1 and ground. If 1 V or greater, repair the short to voltage in the circuit. If the G10 Cooling Fan Motor is not operating
Replace the K22 Cooling Fan Control Module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Fan Control Module Replacement (LCV, LFX without KC4, LTG without V03)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system)
«Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references)

Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Certain resistance conditions with IAT or ECT sensors may cause unwarranted cooling fan activation. If the ECM is commanding the cooling fan ON for no apparent reason and without any component or system DTCs set, the IAT or ECT sensor may be skewed. If this condition is suspected, refer to the temperature versus resistance tables in the appropriate engine controls subsection.
The cooling fan will not operate when the scan tool Cooling Fan Motor Command parameter displays less than 4 %. This is a normal condition.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

«Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON.
Verify that DTC P0480, P0691, or P0692, is not set. If a DTC is set Refer to «DTC P0480, P0691, or P0692»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) , «DTC P0480, P0691, or P0692 (LTG w/V03 or Manual Transmission)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) . If no DTC is set.
Verify the scan tool Cooling Fan Motor Command parameter is less than 4 %. If 4 % or greater Refer to Diagnostic Aids and «Symptoms - Engine Cooling»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) for further diagnosis. If less than 4 %
Verify that the G10 Cooling Fan Motor is not operating. If the G10 Cooling Fan Motor is operating Test or replace the G10 Cooling Fan Motor. If the G10 Cooling Fan Motor is not operating
All OK.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Engine Coolant Fan Shroud Replacement (LTG with VO3)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) for G10 Cooling Fan Motor Replacement.
«Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references)

Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The cooling fan will not operate when the scan tool Cooling Fan Motor Command parameter displays less than 4 %. This is a normal condition.
A delay or ramp up of approximately 12 seconds may occur before the cooling fan activates or changes speed when being commanded with a scan tool.
The cooling fan Control Function operates as described below when the ignition is ON, and engine is OFF: Command State 1 operates the cooling fan at approximately 18-21 % Command State 2 operates the cooling fan at approximately 54 % Command State 3 operates the cooling fan at approximately 67 % Command State 4 operates the cooling fan at approximately 85 % Command State 5 operates the cooling fan at approximately 90 %
During normal operating conditions the ECM may initially activate the cooling fan at 4 or 5 % and then increase to the percentages indicated above, as needed, to satisfy powertrain cooling requirements. Generally, the ECM will operate the cooling fan at the specified percentages but, may scale the percentages either higher or lower in response to generator demand.
When operating the cooling fan with a scan tool, the Commanded States 1-5 should be exercised in order, from OFF to High or High to OFF. The cooling fan control module may disable the cooling fan if a Commanded State is skipped.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

«Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
«Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Special Tools

EL 36169-HD Heavy Duty Fused Jumper

Ignition ON.
Verify that DTC P0480, P0691, or P0692, is not set. If a DTC is set Refer to «DTC P0480, P0691, or P0692»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) , «DTC P0480, P0691, or P0692 (LTG w/V03 or Manual Transmission)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) . If no DTC is set.
Verify the G10 Cooling Fan Motor activates and increases in speed with each command using a scan tool. The cooling fan does not activate or increase in speed Refer to Circuit/System Testing The cooling fan activates and increases in speed
All OK.

Ignition OFF, disconnect the harness connector X1 at the K22 Cooling Fan Control Module.
Verify that a test lamp illuminates between the ground circuit terminal 1 and B+. If the test lamp does not illuminate Ignition OFF, and all vehicle systems OFF, it may take up to 2 minutes for all vehicle systems to power down. 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 the test lamp illuminates
Disconnect the K22 Cooling Fan Control Module harness connector X2 from the G10 Cooling Fan Motor.
Connect the K22 Cooling Fan Control Module harness connector X1.
Verify a test lamp illuminates between the K22 Cooling Fan Control Module terminal X2-2 and B+. If the test lamp does not illuminate Replace the K22 Cooling Fan Control Module. If the test lamp illuminates
Ignition ON.
Connect a test lamp between the K22 Cooling Fan Control Module terminal X2-1 and ground.
Verify the test lamp illuminates when commanding the cooling fan ON with a scan tool. If the test lamp does not illuminate Replace the K22 Cooling Fan Control Module. If the test lamp illuminates
Test or replace the G10 Cooling Fan Motor.

Ignition OFF.
Disconnect the G10 Cooling Fan Motor harness connector X2 from the K22 Cooling Fan Control Module.
Connect the EL 36169-HD between the G10 Cooling Fan Motor terminal 1 and B+. Connect a jumper wire between the G10 Cooling Fan Motor terminal 2 and ground.
Verify the G10 Cooling Fan Motor operates. The cooling fan does not operate Replace the G10 Cooling Fan Motor. The cooling fan operates
All OK.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Engine Coolant Fan Motor Replacement (LCV, LFX without KC4, LTG without V03)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system)
«Fan Control Module Replacement (LCV, LFX without KC4, LTG without V03)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system)
«Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references)

Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
«Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The cooling fan will not operate when the scan tool Cooling Fan Motor Command parameter displays less than 4 %. This is a normal condition.
A delay or ramp up of approximately 12 seconds may occur before the cooling fan activates or changes speed when being commanded with a scan tool.
The cooling fan Control Function operates as described below when the ignition is ON, and engine is OFF: Command State 1 operates the cooling fan at approximately 18 % Command State 2 operates the cooling fan at approximately 54 % Command State 3 operates the cooling fan at approximately 67 % Command State 4 operates the cooling fan at approximately 85 % Command State 5 operates the cooling fan at approximately 90 %
During normal operating conditions the ECM may initially activate the cooling fan at 4 or 5 % and then increase to the percentages indicated above, as needed, to satisfy powertrain cooling requirements. Generally, the ECM will operate the cooling fan at the specified percentages but, may scale the percentages either higher or lower in response to generator demand.
When operating the cooling fan with a scan tool, the Commanded States 1-5 should be exercised in order, from OFF to High or High to OFF. The cooling fan control module may disable the cooling fan if a Commanded State is skipped.

Schematic Reference

Connector End View Reference

Description and Operation