2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1764
Schematic Reference
Engine Controls Schematics (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General
Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring
Repairs/Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code
(DTC) Type Definitions)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Verification
1. Ignition OFF, inspect the cooling system surge tank for the proper coolant level. Refer to Cooling System Leak Testing (See: Engine,
Cooling and Exhaust/Cooling System/Testing and Inspection/Component Tests and General Diagnostics) and Cooling System Draining and
Filling (Static Fill) (See: Engine, Cooling and Exhaust/Cooling System/Service and Repair/Cooling System Draining and Filling (Static Fill)
).
2. Inspect the thermostatically-controlled coolant heater, if equipped, for damage or modifications. Test for proper operation of the coolant
heater. Refer to Coolant Heater Inoperative (See: Engine, Cooling and Exhaust/Cooling System/Testing and Inspection/Symptom Related
Diagnostic Procedures/Coolant Heater Inoperative).
3. Ignition OFF for 8 h or greater.
4. Ignition ON, observe the scan tool IAT and ECT sensor parameters. The ECT, IAT, and ambient temperature should be within 6掳C (11掳F) of
each other.
5. 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 harness connector at the B34 ECT sensor.
2. Ignition OFF for 90 s, test for less than 5 ohm between the low reference circuit terminal A and ground.
瀚慖f greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20
ECM.
3. Ignition ON, verify the scan tool ECT parameter is colder than -39掳C (-38掳F).
瀚慖f greater than the specified range, test the signal circuit terminal B for a short to ground. If the circuit tests normal, replace the K20 ECM.
4. Install a 3 A fused jumper wire between the signal circuit terminal B and the low reference circuit terminal A. Verify the scan tool ECT
parameter is greater than 149掳C (300掳F).
瀚慖f less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace
the K20 ECM.
5. If all circuits test normal, test or replace the B34 ECT sensor.
6. Inspect for the proper operation of the OEM block heater cord by verifying that the thermostat has turned OFF the heater at temperatures
warmer than -10掳 (+14掳F).
Component Testing
Measure and record the resistance of the ECT sensor at various ambient temperatures, then compare those measurements to the Temperature Versus
Resistance (See: Powertrain Management/Computers and Control Systems/Specifications/Temperature Versus Resistance).
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
