2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 1852
* 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
Special Tools
* J-35555 Metal Mityvac
* J-23738-A Mityvac
Circuit/System Verification
1. If DTC P0641 or P0651 are set, refer to DTC P0641 or P0651 (ECM) (See: P Code Charts/P0641).
2. Verify that restrictions do not exist in the exhaust system. Refer to Restricted Exhaust (See: Engine, Cooling and Exhaust/Exhaust
System/Testing and Inspection/Restricted Exhaust).
3. Verify that the engine is in good mechanical condition. Refer to Symptoms - Engine Mechanical (See: Engine, Cooling and
Exhaust/Engine/Testing and Inspection/Symptom Related Diagnostic Procedures/Symptoms - Engine Mechanical) for the 4.8L, 5.3L, 6.0L
and 6.2L engine.
4. Ignition OFF for 90 s, determine the current vehicle testing altitude. Ignition ON, observe the scan tool BARO Sensor parameter. Compare
the parameter to the Altitude Versus Barometric Pressure (See: Powertrain Management/Computers and Control
Systems/Specifications/Altitude Versus Barometric Pressure) table. The BARO sensor pressure parameter should be within the specified
range indicated in the table.
5. A skewed MAP sensor will also cause the first and second intake manifold models to disagree with the actual MAP sensor measurements.
Use the scan tool and compare the MAP Sensor parameter to a known good vehicle under various operating conditions. The readings should
be within 3 kPa of the known good vehicle.
6. Ignition ON, observe the scan tool MAP sensor parameter. Start the engine. The MAP Sensor parameter should change.
瀚慖f the vehicle passes the Circuit System Verification Test, operate the vehicle within the Conditions for Running the DTC. You may also
operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records list.
Circuit/System Testing
Note: All electrical components and accessories must be turned OFF and allowed to power down.
1. Verify the integrity of the air induction system by inspecting for the following conditions:
* Any damaged components
* Loose or improper installation
* Improperly routed vacuum hoses
* Any vacuum leak
* Any type of restriction
* MAP sensor seal that is missing or damaged
2. Verify that restrictions do not exist in the MAP sensor vacuum source.
3. Verify that restrictions do not exist in the exhaust system. Refer to Restricted Exhaust (See: Engine, Cooling and Exhaust/Exhaust
System/Testing and Inspection/Restricted Exhaust).
4. Ignition OFF, disconnect the MAP harness connector at the MAP sensor.
5. 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 value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
6. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal C and ground.
瀚慖f less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal,
replace the ECM.
瀚慖f greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
7. Verify the scan tool MAP Sensor parameter is less than 12 kPa.
瀚慖f greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
8. Install a 3 A fused jumper wire between the signal circuit terminal B and the 5 V reference circuit terminal C. Verify the scan tool MAP
Sensor parameter is greater than 103 kPa.
