Engine Control System &amp; Fuel System - 2.8l, 3.0l - DTC p0300 to DTC p0455 Cadillac SRX II

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/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

Special Tools

J 26792 HEI Spark Tester. See Special Tools .

Circuit/System Verification

Engine idling at the normal operating temperature, there should be no abnormal engine noise. If there is an abnormal engine noise, refer to «Symptoms - Engine Mechanical»(/cadillac/srx/ii-2009-2012/remont/mechanical/#engine-mechanical-28l-or-30l-diagnostic-information-and-procedures) .
Verify that no other DTCs are set. If a DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
Observe the scan tool Misfire Current Cyl. 1-6 parameters. The Misfire Current Counters should not be incriminating.
Observe the scan tool Circuit Test Status parameters for the various components that may cause a misfire. Verify the Circuit Test Status parameters for the components that may cause a misfire display OK or Not Run.
Engine idling, perform the cylinder power balance test with a scan tool to isolate the misfiring cylinder. The engine speed should change when each injector is disabled.
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

Verify that the following conditions do not exist: Vacuum hose splits, kinks, and incorrect connections Engine vacuum leaks Crankcase ventilation system for vacuum leaks Fuel pressure that is too low or too high - Refer to «Fuel System Diagnosis (LAU China)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) or «Fuel System Diagnosis (LAU Except China)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Contaminated Fuel - Refer to «Alcohol/Contaminants-in-Fuel Diagnosis (Special Tool)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) or «Alcohol/Contaminants-in-Fuel Diagnosis (Without Special Tool)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Exhaust system restrictions If you find any of the above conditions, repair as necessary.
Ignition OFF, remove the appropriate T8 ignition coil of the misfiring cylinder, but leave the electrical connector connected.
Inspect the ignition coil boot for the following conditions: Holes Tears Carbon tracking Oil contamination water intrusion If you find any of the above conditions, repair as necessary.
Remove the fuel pump fuse from the fuse block.
Install the J 26792 to the boot of the appropriate T8 ignition coil and ground. See «Special Tools»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-special-tools-equipment) .
Attempt to start the engine and observe the J 26792 . See «Special Tools»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-special-tools-equipment) . The spark tester should spark. If there is no spark, refer to «Electronic Ignition System Diagnosis»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) for diagnosis of the T8 ignition coil.
Ignition OFF, remove the spark plug from the misfiring cylinder. Verify that the spark plug does not exhibit the following conditions: Gas, coolant, or oil fouled - Refer to «Spark Plug Inspection»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions__spark-plug-inspection) . Cracked, worn, incorrectly gapped - Refer to «Ignition System Specifications (LAU)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-specifications__ignition-system-specifications-lau) . If there is a condition with the spark plug, replace the spark plug.
Exchange the suspected spark plug with another cylinder that is operating correctly.
Install the fuel pump fuse in the fuse block.
Engine idling, observe the scan tool Misfire Current Counter parameters. The misfire should not follow the spark plug exchange. If the misfire follows the spark plug, replace the spark plug.
If all conditions test normal, test or inspect for the following: A lean or rich Q17 fuel injector - Refer to «Fuel Injector Solenoid Coil Test (LAU)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . An engine mechanical condition - Refer to «Symptoms - Engine Mechanical»(/cadillac/srx/ii-2009-2012/remont/mechanical/#engine-mechanical-28l-or-30l-diagnostic-information-and-procedures) .

Repair Procedures

Spark Plug Replacement

Repair Verification

Install any components or connectors that have been removed or replaced during diagnosis.
Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
Clear the DTCs.
Turn OFF the ignition for 60 s.
If the repair was related to a DTC, duplicate the Conditions for Running the DTC and use the Freeze Frame/Failure Records, if applicable, in order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) and perform the appropriate diagnostic procedure.
To verify that the performance of the catalytic converter has not been affected by the condition that set this DTC, perform the Repair Verification for DTC P0420 or P0430. Refer to «DTC P0420 or P0430»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-dtc-p0300-to-dtc-p0455) .

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

DTC Descriptor

DTC P0315: Crankshaft Position System Variation Not Learned

The crankshaft position system variation learn feature is used to calculate reference period errors caused by slight tolerance variations in the crankshaft, and the crankshaft position sensor. The calculated error allows the engine control module (ECM) to accurately compensate for reference period variations. This enhances the ability of the ECM to detect misfire events over a wider range of engine speed and load conditions.

The crankshaft position system variation compensating values are stored in ECM memory after a learn procedure has been performed and the ignition switch is turned to the OFF position for at least 30 s. If the actual variation is not within the crankshaft position system variation compensating values stored in the ECM, DTC P0300 may set.

If the crankshaft position system variation values are not stored in the ECM memory or a proper ECM power down does not occur after completing the Crankshaft Position Learn Procedure, DTC P0315 sets.

DTC P0315 runs continuously.

Conditions for Setting the DTC

The ECM detects that the crankshaft position system variation values are not stored in memory.

DTC P0315 is a Type A DTC.

Conditions for Clearing the MIL/DTC

DTC P0315 is a Type A DTC.

This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to Battery Inspection/Test .

Schematic Reference

Engine Controls Schematics (LAU) or Engine Controls Schematics (LF1)

Connector End Views

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Note. The Crankshaft Position System Variation Learn Procedure may have to be repeated up to 5 times before the procedure is successful.

Perform the «Crankshaft Position System Variation Learn (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions__crankshaft-position-system-variation-learn-lf1) procedure. The scan tool should display Learned Successful. If the Crankshaft Position System Variation Learn Procedure cannot be performed successfully, inspect for the following conditions: Worn crankshaft main bearings A damaged or misaligned reluctor wheel Excessive crankshaft runout A damaged crankshaft - Refer to «Crankshaft and Bearing Cleaning and Inspection»(/cadillac/srx/ii-2009-2012/remont/mechanical/#engine-mechanical-28l-or-30l-repair-instructions-off-vehicle-2-of-5) . Interference in the signal circuit of the crankshaft position sensor The ignition switch is in the ON position until there is insufficient system voltage. An ECM power disconnect with the ignition ON that may have erased the crankshaft position system variation values and set DTC P0315 Debris between the crankshaft position sensor and the reluctor wheel
Verify the Learn Procedure is successful. If the K20 ECM is unable to complete the learn procedure, replace the K20 ECM.

Perform the Diagnostic Repair Verification after using this diagnostic procedure.

Control Module References for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The knock sensor is a piezoelectric device that produces an AC voltage of different amplitude and frequency depending on the level of engine mechanical vibration. The knock sensor system monitors the knock sensor in order to determine if detonation or spark knock is present. If the knock sensor system determines that excessive knock is present, the engine control module (ECM) retards the spark timing based on the signal from the knock sensor system. The knock sensor produces an AC signal when specific frequencies are detected. The ECM then retards the timing until knock is controlled.

The ECM tests the functionality of the internal knock sensor signal evaluation circuitry. The knock sensor circuitry within the ECM is responsible for receiving, amplifying, filtering, and evaluating the AC voltage and frequency from the knock sensors. The ECM performs two tests that determine if the internal circuitry within the ECM is functioning correctly.

Test One

The ECM internally turns OFF the knock sensor signal circuits. The ECM then applies different test signals to the internal knock sensor circuitry to verify that each test signal output response is within range. If the ECM detects that any of the test signals are not within range, this DTC sets.

Test Two

The ECM internally turns OFF the knock sensor signal circuits. The ECM then tests for any output response when no test signals are applied. If the ECM detects an output response, this DTC sets.

Test Three

The ECM internally turns OFF the knock sensor signal circuits. The ECM generates an internal test pulse and monitors the return signal. If the return test pulse is less than a calibrated threshold, this DTC sets.

The ECM is controlling spark.
The engine coolant temperature is warmer than 45°C (113°F).
DTC P0324 runs continuously once the above conditions are met.

The ECM detects an incorrect response to the self tests performed on the internal knock sensor circuitry.
The condition exists for greater than 1 s or for a cumulative of 10 s.

DTCs P0324 is a Type B DTC.

Description and Operation

Knock Sensor System Description

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Note. If you can hear an engine knock, repair the engine mechanical condition before proceeding with this diagnostic. Refer to Symptoms - Engine Mechanical .

Ignition ON, observe the DTC information with a scan tool. DTC P0335, P0336, or P0338 should not be set. If DTC P0335, P0336, or P0338 is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for diagnosis of DTC P0335, P0336, or P0338.
Clear the DTCs with a scan tool.
Turn OFF the ignition for 30 s.
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. If DTC P0324 failed this ignition, replace the K20 ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for engine control module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Knock Sensor 1 Signal	P0327	P0325, P06B6	P0328	P0326
Knock Sensor 2 Signal	P0332	P0330, P06B7	P0333	P0331

The knock sensor system enables the engine control module (ECM) to control the ignition timing for the best possible performance while protecting the engine from potentially damaging levels of detonation. The knock sensor produces an AC voltage signal that varies depending on the vibration level during engine operation. The ECM adjusts the spark timing based on the amplitude and the frequency of the knock sensor signal. The ECM receives the knock sensor signal through 2 isolated signal circuits for each bank. The ECM learns a minimum knock sensor noise level for all of the RPM range. The ECM monitors for a normal knock sensor signal. The ECM monitors the internal knock sensor processor by verifying a 20 KHz signal generated on the output circuit is detected on the return circuit.

P0324, P0326 and P0331-Excessive Knock Detection Mode

Engine speed is between 400-8,500 RPM.
The engine coolant temperature (ECT) is warmer than -40°C (-40°F).
The intake air temperature (IAT) is warmer than -40°C (-40°F).
The DTCs run continuously when the above conditions are met.

P0324, P0326 and P0331-Abnormal Noise Detection Mode-Improperly Bolted Knock Sensor

Engine speed is between 2,200-8,500 RPM.
The ECT is warmer than -40°C (-40°F).
The IAT is warmer than -40°C (-40°F).
The DTCs run continuously when the above conditions are met.

P0325, P0327, P0328, P0330, P0332, and P0333

Engine speed is between 400-8,500 RPM.
The ECT is warmer than -40°C (-40°F).
The IAT is warmer than -40°C (-40°F).
The DTCs run continuously when the above conditions are met.

P06B6 and P06B7

Engine speed is between 400-4,000 RPM.
The ECT is warmer than -40°C (-40°F).
The IAT is warmer than -40°C (-40°F).
The DTCs run continuously when the above conditions are met.

P0324

The ECM detects that the knock sensor signal indicates an excessive engine knock is present for greater than 10 s for at least 1 single cylinder.

P0325 and P0330

The ECM detects that the knock sensor signal circuits are open for greater than 10 s.

P0326 and P0331

The ECM detects that the knock sensor signal indicates the sensor harness is connected, but the sensor is not properly bolted to the engine. OR
The ECM detects that the knock sensor signal indicates an excessive engine knock is present in an entire bank.
Either of the above conditions exist for greater than 10 s.

P0327 and P0332

The ECM detects that the knock sensor signal circuits are shorted to ground for greater than 10 s.

P0328 and P0333

The ECM detects that the knock sensor signal circuits are shorted to voltage for greater than 10 s.

The ECM has detected an internal knock sensor processor fault.

DTCs P0324, P0325, P0326, P0327, P0328, P0330, P0331, P0332 P0333, P06B6, and P06B7 are Type B DTCs.
The ignition timing is retarded to reduce the potential of engine damaging spark knock.

DTCs P0324, P0325, P0326, P0327, P0328, P0330, P0331, P0332 P0333, P06B6, and P06B7 are Type B DTCs.

Inspect the knock sensor for physical damage. A knock sensor that is dropped or damaged may cause a DTC to set.
Inspect the knock sensor for proper installation. A knock sensor that is loose or over torqued may cause a DTC to set. The knock sensor should be free of thread sealant.
The knock sensor mounting surface should be free of burrs, casting flash, and foreign material.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/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

Engine at operating temperature, all accessories OFF, and engine speed greater than 2,000 RPM, observe the Knock Retard and Total Knock Retard parameters. The parameters should be 0°.
Engine idling, move the related harnesses and connectors for the KS circuits while observing the scan tool Knock Retard and Total Knock Retard parameters. The parameters should remain steady with no abrupt changes.
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.

Note. Perform the Diagnostic System Check - Vehicle prior to using these diagnostic procedures. If an engine mechanical noise can be heard, repair the condition before proceeding with this diagnostic. Refer to Symptoms - Engine Mechanical .

P0324, P0326 and P0331

Using a scan tool, verify DTCs P0335 or P0336 are not set. If any of the DTCs are set, diagnose them first. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
Verify the following conditions do not exist. A loose or broken vehicle accessory A loose or broken accessory bracket Excessive engine mechanical noise If any of the conditions exist, repair as necessary.
Replace the K20 ECM if no external knock sensor circuit issues exist.

Ignition OFF, disconnect the affected B68 KS.
Verify the affected B68 KS is properly tightened, refer to «Fastener Tightening Specifications»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-specifications__fastener-tightening-specifications) .
Ignition OFF, with appropriate length jumper wires, connect the B68A KS1 harness to the B68B KS2 sensor and the B68B KS2 harness to the B68A KS1 sensor.
Monitor the DTCs using a scan tool. Operate the vehicle within the conditions for running the DTC. Verify the fault does not follow the sensor in question. If the fault follows the sensor in question, replace the appropriate B68 KS.
Ignition OFF, remove the jumper wires from the previous step.
Ignition ON, measure for 1-4 V between each of the following circuits and ground on the K20 ECM side of the harness connector: The B68 KS signal circuit, terminal A or 1 The B68 KS signal circuit, terminal B or 2 If less than the specified range, test the circuits for a short to ground or an open/high resistance. If the circuits test normal, replace the K20 ECM. If greater than the specified range, test the circuits for a short to voltage. If the circuits test normal, replace the K20 ECM.
Test for intermittent or poor connections at the ECM, B68 KS, and in-line connectors where present.
If all circuits test normal, replace the K20 ECM.

P06B6 or P06B7

Using a scan tool, verify the following DTCs are not set: P0325, P0327, P0328, P0330, P0332, and P0333. If any of the DTCs are set, diagnose them first.
DTCs P06B6 and P06B7 indicate an internal ECM circuitry failure. Verify the external knock sensor circuits and connectors for proper condition. If no external knock sensor circuit issues exist, replace the K20 ECM.

«Knock Sensor Replacement - Bank 1»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Knock Sensor Replacement - Bank 2»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

In order to differentiate between normal engine noise and spark knock, the ECM samples the knock sensor signal. The ECM samples the knock sensor signal for a certain length of time under different engine speeds and loads during non-cylinder knock events. This sampling is used to determine a range of acceptable normal engine noise.

The engine speed is greater than 1,600 RPM.
The ECM is controlling spark.
DTCs P0326 and P0331 run continuously once the above conditions are met.

P0327, P0328, P0332, and P0333

DTCs P0324, P0335, P0336, P0338, P0341, P0342, P0343, P0346, P0347, P0348, P0366, P0367, P0368, P0391, P0392, P0393 are not set.
The engine speed is greater than 1,960 RPM.
The ECM is controlling spark.
The increase in engine speed is less than a range of 1,400-3,700 RPM per second.
The engine load is in the range of 35-65 kPa per second.
DTCs P0327, P0328, P0332, and P0332 run continuously once the above conditions are met for approximately 20 s.

The ECM detects a knock sensor signal voltage that is not in the range of a predetermined engine noise level in 25 of 250 test samples. The condition exists for greater than 1 s or for a cumulative of 10 s.

P0327 or P0332

The ECM detects a knock sensor signal voltage that is less than the predetermined minimum engine noise level for greater than 1 s or for a cumulative of 10 s.

P0328 or P0333

The ECM detects the knock sensor signal voltage is greater than predetermined maximum engine noise level for greater than 1 s or for a cumulative of 10 s.

DTCs P0326, P0327, P0328, P0331, P0332, and P0333 are Type B DTCs.

Inspect the knock sensor for physical damage. A knock sensor that is dropped or damaged may cause a DTC to set.
Inspect the knock sensor for proper installation. A knock sensor that is loose or over torqued may cause a DTC to set. The knock sensor should be free of thread sealant. The knock sensor mounting surface should be free of burrs, casting flash, and foreign material.
The knock sensor must be clear of hoses, brackets, and engine electrical wiring.
With the knock sensor disconnected, the normal voltage measured from the knock sensor signal or the low reference circuit to ground is between 2.30-2.80 V.

Schematic Reference

Connector End View Reference

Knock Sensor System Description

Description and Operation

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/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 at operating temperature, all accessories OFF. Engine speed greater than 2,000 RPM, observe the appropriate scan tool knock sensor signal voltage parameter. The voltage should be greater than 4.0 V.
Engine idling, move the related harnesses and connectors for the knock sensor circuits while observing the scan tool knock sensor signal voltage parameters. The voltage should remain steady with no abrupt changes.
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.

Ignition OFF, disconnect the harness connector at the appropriate B68 knock sensor.
Ignition ON, test for 2-3 V between the signal circuit terminal A or 1 and ground. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuits/connections test normal, replace the K20 ECM. If greater than the specified range, test the signal circuit for a short to voltage. If the circuits/connections test normal, replace the K20 ECM.
Test for 2-3 V between the low reference circuit terminal B or 2 and ground. If less than the specified range, test the low reference circuit for a short to ground or an open/high resistance. If the circuits/connections test normal, replace the K20 ECM. If greater than the specified range, test the low reference circuit for a short to voltage. If the circuits/connections test normal, replace the K20 ECM.
If all circuits/connections test normal, test or replace the appropriate B68 knock sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Knock Sensor Replacement - Bank 1»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Knock Sensor Replacement - Bank 2»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Engine Control Module replacement, setup, and programming.

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/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
5 V Reference Circuit	P0651	P0335	P0651, P2135
Crankshaft Position Sensor Signal Circuit	P0335	P0335	P0335	P0336
Low Reference Circuit		P0335	P0335

The crankshaft position sensor circuits consist of an engine control module (ECM) supplied 5 V reference circuit, low reference circuit and an output signal circuit. The crankshaft position sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes of the teeth and slots of a 58-tooth reluctor wheel on the crankshaft. Each tooth on the reluctor wheel is spaced at 60-tooth spacing, with 2 missing teeth for the reference gap. The crankshaft position sensor produces an ON/OFF DC voltage of varying frequency, with 58 output pulses per crankshaft revolution. The frequency of the crankshaft position sensor output depends on the velocity of the crankshaft. The crankshaft position sensor sends a digital signal, which represents an image of the crankshaft reluctor wheel, to the ECM as each tooth on the wheel rotates past the crankshaft position sensor. The ECM uses each crankshaft position signal pulse to determine crankshaft speed and decodes the crankshaft reluctor wheel reference gap to identify crankshaft position. This information is then used to determine the optimum ignition and injection points of the engine. The ECM also uses crankshaft position sensor output information to determine the camshaft relative position to the crankshaft, to control camshaft phasing, and to detect cylinder misfire.

DTCs P0101, P0102, P0103, P0340, P0341, P0641, or P0651 P0697 are not set.
The engine is cranking or running.
The airflow into the engine is greater than 3 g/s.
The DTC runs continuously when the above conditions are met.

The ECM detects that the starter is commanded ON and the engine has been cranking for more than 4 seconds without a crankshaft position sensor pulse.
The ECM detects that the engine has been running but has not received a crankshaft position sensor pulse for 2 of 10 engine revolutions.

DTC P0335 is a Type B DTC.
The camshaft position actuator is commanded to the Home or Parked position.

DTC P0335 is a Type B DTC.

Schematic Reference

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Electronic Ignition System Description»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-description-operation__electronic-ignition-system-description)
«Engine Control Module Description»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-description-operation__engine-control-module-description)

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Engine Control Module Scan Tool Information (LF1,LFW) for scan tool information

Engine idling, observe the scan tool Crankshaft Position Active Counter parameter. The parameter should be incrementing.
Engine idling, observe the DTC information with a scan tool. DTC P0335 should not set.
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.

Ignition OFF, disconnect the B26 crankshaft position sensor connector.
Ignition OFF, vehicle systems OFF, this may take up to 2 minutes, test for less than 3 ohms between low reference circuit terminal 1 and ground. If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 3 and ground. If less than the specified range, test the 5 V reference circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the K20 ECM. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
Test for 4.8-5.2 V between the signal circuit terminal 2 and ground. If less than the specified range, test the signal circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the K20 ECM. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
Ignition ON, engine OFF, using a 3 A jumper wire connected to ground, momentarily touch the crankshaft position sensor signal circuit terminal 2 repeatedly. The crankshaft position active counter parameter should increment. If the crankshaft position active counter parameter does not increment, replace the K20 ECM. If the crankshaft position active counter increments, test or replace the B26 crankshaft position sensor.

Component Testing

Note. You must perform the Circuit/System Testing before proceeding with Component Testing.

Inspect the B26 crankshaft position sensor for looseness and correct installation. Remove the crankshaft position sensor from the engine and inspect the sensor and the O-ring for damage. If the sensor is loose, incorrectly installed, or damaged, repair or replace the B26 crankshaft position sensor.
Connect the crankshaft position sensor connector to the crankshaft position sensor. Turn ON the ignition, with the engine OFF.
Observe the Crankshaft Position Active Counter parameter with a scan tool. Pass a flat steel object by the tip of the sensor repeatedly. The crankshaft position active counter parameter should increment. If the function does not perform as specified, replace the B26 crankshaft position sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Crankshaft Position Sensor Replacement»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/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
5-Volt Reference	P0122, P0222, P0335, P0698, P2127	P0335, P0697	P0335, P0338, P0699	P0336, P0697, P0698, P0699
Crankshaft Position Sensor Signal	P0122, P0222, P0335, P0698, P2127	P0335	P0335, P0338, P0699	P0336, P0698, P0699
Low Reference	P0335	P0335		P0336

The crankshaft position sensor is located on the rear of bank 1 of the engine block. The crankshaft position sensor is a hall effect switch that works in conjunction with a 58X reluctor wheel that is attached to the crankshaft. Each tooth on the reluctor wheel is spaced 6 degrees apart with one span having a 12 degree space. The engine control module (ECM) uses the 12 degree space to determine top dead center (TDC) for cylinders 1 and 4. The ECM determines when cylinder 1 is on the compression stroke by monitoring the crankshaft position sensor and the camshaft position sensors. The ECM can synchronize the ignition timing, fuel injector timing, and spark knock control based on the crankshaft position sensor and the camshaft position sensor inputs.

The engine is cranking or operating.
The ECM has detected greater than 12 camshaft revolutions.
The DTC P0335 and P0336 run continuously once the above conditions are met for greater than 5 seconds.
The DTC P0338 runs once each engine revolution once the above conditions are met for greater than 2 seconds.

P0335

The ECM does not detect a signal from the crankshaft position sensor. OR
The ECM detects a crankshaft position signal with out reference pulse for greater than 3 revolutions, 6 revolutions for LLT.
Either condition exists for greater than 1 second or a cumulative of 10 seconds.

P0336

The ECM re-syncs the engine position 6 or more times during an ignition cycle.
The ECM re-syncs the engine position 2,600 or more times during an ignition cycle, for LLT. OR
The ECM detects 28 or more interruptions in the engine speed signal during an ignition cycle.
Either condition exists for greater than 1 second or a cumulative of 10 seconds.

P0338

The ECM detects a difference of greater than 8 teeth between reference gap position pulses.
The ECM detects a difference of greater than 250 teeth between reference gap position pulses, for LLT.
The condition exists for greater than 1 second or a cumulative of 10 seconds.

DTCs P0335, P0336, and P0338 are Type A DTCs.

The following conditions could also set the DTCs

Physical damage to the crankshaft position sensor or the reluctor wheel
Excessive play or looseness of the crankshaft position sensor or the reluctor wheel
Improper installation of the crankshaft position sensor or the reluctor wheel
Foreign material passing between the crankshaft position sensor and the reluctor wheel
Excessive air gap between the crankshaft position sensor and the reluctor wheel
The ECM uses the camshaft position sensors to determine engine speed and position when there is a crankshaft position sensor condition.
The engine will operate with a crankshaft position sensor condition only if the ECM has stored the learned reference position of the camshafts in memory. With a crankshaft position sensor condition the engine will go into a limp home mode after a restart. The ECM then calculates engine speed from one of the camshaft position sensors.
An intermittent condition in the camshaft position sensor circuits can cause a crankshaft position DTC to set. Inspect the camshaft position sensor, harness connections, and related wiring, if you suspect this condition.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/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, observe the DTC information with a scan tool. DTC P0697, P0698, or P0699 should not be set. If a DTC is set, refer to «DTC P0641-P0643, P0651-P0653, or P0697-P0699 (ECM, LAU)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-dtc-p0455-to-dtc-p150cp1400) .
Clear the DTC Info with a scan tool. Attempt to start the engine, observe the DTC information with a scan tool. DTC P0335, P0336, or P0338 should not set.
Observe the scan tool crankshaft position Resync parameter, the parameter should always display zero. Move the related harnesses/connectors of the crankshaft position sensor while observing the parameter, verify the engine does not stumble, or stall, and the parameter does not increment.
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.

Ignition OFF, remove the fuse that supplies B+ to terminal 56-X2 of the ECM.
Disconnect the harness connector at the crankshaft position sensor.
Test for 5 ohms or less between the low reference circuit terminal 1 and ground. If greater than the specified range, test for an open/high resistance in the low reference circuit. If the circuits/connections test normal, replace the ECM.
Install the fuse that supplies B+ to terminal 56-X2 of the ECM.
Ignition ON, test for greater than 4.8 V between the 5-volt reference circuit terminal 3 and the low reference circuit terminal 1. If less than the specified value, test for an open/high resistance in the 5-volt reference circuit. If the circuits/connections test normal, replace the ECM.
Test for 4.8-5.2 V between the signal circuit terminal 2 and ground. If the voltage is greater than specified range, test for a short to voltage in the signal circuit. If circuit/connections test normal, replace the ECM. If the voltage is less than the specified range, test for a short to ground or an open/high resistance in the signal circuit. If circuit/connections test normal, replace the ECM.
If all circuits/connections test normal, test or replace the crankshaft position sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Crankshaft Position Sensor Replacement»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/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
5 V Reference Circuit	P0651	P0335	P0651, P2135
Crankshaft Position Sensor Signal Circuit	P0335	P0335	P0335	P0336
Low Reference Circuit		P0335	P0335

DTCs P0101, P0102, P0103, P0340, P0341, P0641, or P0651 are not set.
The engine is cranking or running.
The airflow into the engine is greater than 3 g/s.
The DTC runs continuously when the above conditions are met.

The ECM detects that the engine is running, but receives less than 51 or more than 65 crankshaft position sensor pulses each engine revolution for 8 of 10 engine revolutions.
The ECM detects that the engine is running, but more than 19 resyncs occur within 25 seconds.
The ECM detects that the engine has been running, but the crankshaft does not sync for 0.4 second.

DTC P0336 is a Type B DTC.
The camshaft position actuator is commanded to the Home or Parked position.

DTC P0336 is a Type B DTC.

Schematic Reference

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

«Electronic Ignition System Description»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-description-operation__electronic-ignition-system-description)
«Engine Control Module Description»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-description-operation__engine-control-module-description)

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Engine Control Module Scan Tool Information (LF1,LFW) for scan tool information

Engine idling, observe the scan tool Crankshaft Position Active Counter parameter. The parameter should be incrementing.
Engine idling, observe the DTC information with a scan tool. DTC P0335 should not set.
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.

Ignition OFF, disconnect the B26 crankshaft position sensor connector.
Ignition OFF, vehicle systems OFF, this may take 2 minutes, test for less than 3 ohms between low reference circuit terminal 1 and ground. If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 3 and ground. If less than the specified range, test the 5 V reference circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the K20 ECM. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
Test for 4.8-5.2 V between the signal circuit terminal 2 and ground. If less than the specified range, test the signal circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the K20 ECM. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
Ignition ON, engine OFF, using a 3 A jumper wire connected to ground, momentarily touch the crankshaft position sensor signal circuit terminal 2 repeatedly. The Crankshaft Position Active Counter parameter should increment. If the Crankshaft Position Active Counter parameter does not increment, replace the K20 ECM. If the Crankshaft Position Active Counter increments, test or replace the B26 crankshaft position sensor.

Note. You must perform the Circuit/System Testing before proceeding with Component Testing.

Inspect the B26 crankshaft position sensor for looseness and correct installation. Remove the crankshaft position sensor from the engine and inspect the sensor and the O-ring for damage. If the sensor is loose, incorrectly installed, or damaged, repair or replace the B26 crankshaft position sensor.
Connect the crankshaft position sensor connector to the crankshaft position sensor. Turn ON the ignition, with the engine OFF.
Observe the Crankshaft Position Active Counter parameter with a scan tool. Pass a steel object by the tip of the sensor repeatedly. The Crankshaft Position Active Counter parameter should increment. If the function does not perform as specified, replace the B26 crankshaft position sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Crankshaft Position Sensor Replacement»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/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
5 V Reference Circuit	P0641, P0452, P0107, P0532, P0522	P0340, P0345, P0365, P0390	P0641
Camshaft Position Sensor Signal Circuit	P0340, P0345, P0365, P0390	P0340, P0345, P0365, P0390	P0340, P0345, P0365, P0390	P0341, P0346, P0366, P0391
Low Reference Circuit		P0340, P0345, P0365, P0390	P0340, P0345, P0365, P0390

The 4X camshaft position sensor circuits consist of an engine control module (ECM) supplied 5 V reference circuit, low reference circuit, and an output signal circuit. The camshaft position sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes of the teeth and slots of a 4-tooth reluctor wheel attached to the camshaft. As each reluctor wheel tooth rotates past the camshaft position sensor, the resulting change in the magnetic field is used by the sensor electronics to produce a digital output pulse. The sensor returns a digital ON/OFF DC voltage pulse of varying frequency, with 4 varying width output pulses per camshaft revolution that represent an image of the camshaft reluctor wheel. The frequency of the camshaft position sensor output depends on the velocity of the camshaft. The ECM decodes the narrow and wide tooth pattern to identify camshaft position. The ECM uses the cylinder 1 intake camshaft position sensor to determine injector and ignition system synchronization. Also, the cylinder 1 intake camshaft position sensor is used to determine camshaft to crankshaft relationship. This information is then used to determine the optimum ignition and injection points of the engine. The ECM also uses camshaft position sensor output information to determine the camshaft relative position to the crankshaft, to control camshaft phasing, and for limp-home operation.

Note. The ECM detects engine movement by sensing the airflow through the MAF sensor when airflow is greater than 3 g/s, or by sensing crankshaft position sensor pulses.

DTC P0102, P0103, P0335, P0336, P0641, P0651, or P0697 is not set.
The engine is cranking or running.
The DTC runs continuously when the above conditions are met.

The ECM detects that the starter is commanded ON and the engine has been cranking for more than 4 seconds without a camshaft position sensor pulse.
The ECM detects that the engine has started, but did not receive a camshaft position sensor pulse during the first engine revolution.
The ECM detects that the engine is running, but does not receive a camshaft position sensor pulse for 800 of 1,000 engine cycles.

DTCs P0340, P0345, P0365, and P0390 are Type B DTCs.
The camshaft position actuator is commanded to the Home or Parked position.

DTCs P0340, P0345, P0365, and P0390 are Type B DTCs.

With a DTC set, the engine may crank for an extended period of time at start-up.
The cylinder 1 intake camshaft position sensor is used for injector and ignition system synchronization. A stalling condition will occur if the CMP sensor signal is intermittent and a DTC will not set. Inspect all cylinder 1 intake camshaft position sensor circuits for poor connections.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Engine Control Module Scan Tool Information (LF1,LFW) for scan tool information

With the ignition OFF, inspect the engine wiring harnesses carrying the B23 camshaft position sensor circuits for the following conditions: Close routing of aftermarket electrical equipment Close to solenoids, motors, and relays Correct any wire harness routing or component placement conditions if it is determined to be a possible source of electrical interference.
Observe the following scan tool parameters are all incrementing: Exhaust Camshaft Position Active Counter Bank 1 Intake Camshaft Position Active Counter Bank 1 Exhaust Camshaft Position Active Counter Bank 2 Intake Camshaft Position Active Counter Bank 2
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.

Ignition OFF, all vehicle systems OFF, this may take 2 minutes, disconnect the affected B23 camshaft position sensor connector.
Test for less than 3 ohms between the low reference circuit terminal 1 and ground. If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 3 and ground. If less than the specified range, test the 5 V reference circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the K20 ECM. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
Test for 4.8-5.2 V between the signal circuit terminal 2 and ground. If less than the specified range, test the affected signal circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the K20 ECM. If greater than the specified range, test the affected signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
Ignition ON, using a 3 A fused jumper wire connected to ground; momentarily touch the camshaft position sensor signal circuit terminal 2 repeatedly. The appropriate camshaft position active counter parameter should increment. If the camshaft position active counter does not increment, replace the K20 ECM. If the circuits test normal, replace the B23 camshaft position sensor.

Note. You must perform the Circuit/System Testing before proceeding with Component Testing.

Inspect the B23 crankshaft position sensor for looseness and correct installation. Remove the crankshaft position sensor from the engine and inspect the sensor and the O-ring for damage. If the sensor is loose, incorrectly installed, or damaged, repair or replace the B23 crankshaft position sensor.
Connect the crankshaft position sensor connector to the crankshaft position sensor.
Ignition ON, observe the applicable camshaft position active counter parameter with a scan tool. Pass a steel object by the tip of the sensor repeatedly. The camshaft position active counter parameter should increment. If the function does not perform as specified, replace the B23 camshaft position sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Camshaft Position Sensor Replacement - Bank 2 (Left Side) Exhaust»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Camshaft Position Sensor Replacement - Bank 2 (Left Side) Intake»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Camshaft Position Sensor Replacement - Bank 1 (Right Side) Intake»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for K20 ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/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
Camshaft Position Sensor 5-Volt Reference	P0343, P0348, P0368, P0393, P0652, P2122, P2138	P0343, P0348, P0368, P0393, P0651	P0653, P2123, P2138	P0341, P0346, P0366, P0391, P0651, P0652, P0653, P2138
Camshaft Position Sensor Signal Intake Bank 1	P0342	P0343	P0343	P0341
Camshaft Position Sensor Signal Intake Bank 2	P0347	P0348	P0348	P0346
Camshaft Position Sensor Signal Exhaust Bank 1	P0367	P0368	P0368	P0366
Camshaft Position Sensor Signal Exhaust Bank 2	P0392	P0393	P0393	P0391
Low Reference		P0343, P0348, P0368, P0393		P0341, P0346, P0366, P0391

Each camshaft is equipped with a camshaft position sensor that the engine control module (ECM) monitors. The camshaft position sensor is a hall effect switch that works in conjunction with a 4X reluctor wheel. The reluctor wheels are mounted to the camshaft position actuators that are mounted to the end of the camshafts. The ECM uses the camshaft position sensor signals in order to determine the position of the camshafts.

The ECM uses the cylinder 1 intake camshaft position sensor to determine injector and ignition system synchronization. Also, the cylinder 1 intake camshaft position sensor is used to determine camshaft to crankshaft relationship.

The ECM supplies 5 volts to the camshaft position sensors on the 5-volt reference circuits, and supplies a ground on the low reference circuits. The camshaft position sensors provide a signal to the ECM on the signal circuits. If the ECM detects extra or missing camshaft position sensor signal transitions, or a signal voltage that is more or less than the predetermined range, within a certain number of crankshaft revolutions, one of these DTCs sets.

The ECM detects greater than 10 crankshaft revolutions.
The engine speed is less than 2,520 RPM.
The DTCs run continuously once the above condition is met.

P0341, P0346, P0366, P0391

The ECM detects a signal from the camshaft position sensor, but the number of pulses are less than or greater than what is expected for one crankshaft revolution. OR
The camshaft position sensor does NOT correlate to the crankshaft position.
Either condition exists for greater than 1 second, or cumulative of 10 seconds.

P0342, P0347, P0367, P0392

The camshaft position sensor signal voltage is always low and the ECM detects no pulses from the camshaft position sensor for greater than 1 second, or cumulative of 10 seconds.

P0343, P0348, P0368, P0393

The camshaft position sensor signal voltage is always high and the ECM detects no pulses from the camshaft position sensor for greater than 1 second or cumulative of 10 seconds.

DTCs P0341, P0342, P0343, P0346, P0347, P0348, P0366, P0367, P0368, P0391, P0392, and P0393 are Type B DTCs.

The following conditions can also set the DTC

Physical damage to the camshaft position sensor or the reluctor wheel
Excessive play or looseness of the camshaft position sensor or the reluctor wheel
Improper installation of the camshaft position sensor or the reluctor wheel
Foreign material passing between the camshaft position sensor and the reluctor wheel
Excessive air gap between the camshaft position sensor and the reluctor wheel
The cylinder 1 intake camshaft position sensor is used for injector and ignition system synchronization. A stalling condition will occur if the CMP sensor signal is intermittent and a DTC will not set. Inspect all cylinder 1 intake camshaft position sensor circuits for poor connections.

Schematic Reference

Connector End View Reference

Camshaft Actuator System Description

Description and Operation

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/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, observe the DTC information with a scan tool. DTC P0651, P0652 or P0653 should not be set. If a DTC is set, refer to «DTC P0641-P0643, P0651-P0653, or P0697-P0699 (ECM, LAU)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-dtc-p0455-to-dtc-p150cp1400) .
Engine idling, observe the DTC information with a scan tool. DTC P0341, P0342, P0343, P0346, P0347, P0348, P0366, P0367, P0368, P0391, P0392, or P0393 should not set.
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.

Ignition OFF, remove the fuse that supplies B+ to terminal 56-X2 of the ECM.
Disconnect the harness connector at the appropriate camshaft position sensor.
Test for 5 ohms or less between the low reference circuit terminal 1 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance or for a short to voltage. If the circuit/connections test normal, replace the ECM.
Install the fuse that supplies B+ to terminal 56-X2 of the ECM.
Ignition ON, test for greater than 4.8 V between the 5-volt reference circuit terminal 3 and ground. If less than the specified value, test the 5-volt reference circuit for an open/high resistance. If the circuits/connections test normal, replace the ECM.
Test for 4.8-5.2 V between the signal circuit terminal 2 and ground. If the voltage is greater than specified range, test for a short to voltage in the signal circuit. If circuit/connections test normal, replace the ECM. If the voltage is less than the specified range, test for a short to ground or an open/high resistance in the signal circuit. If circuit/connections test normal, replace the ECM.
If all circuits/connections test normal, replace the camshaft position sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Camshaft Position Sensor Replacement - Bank 2 (Left Side) Exhaust»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Camshaft Position Sensor Replacement - Bank 2 (Left Side) Intake»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Camshaft Position Sensor Replacement - Bank 1 (Right Side) Exhaust»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Camshaft Position Sensor Replacement - Bank 1 (Right Side) Intake»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/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
5 V Reference Circuit	P0641, P0452, P0107, P0532, P0522	P0340, P0345, P0365, P0390	P0641
Camshaft Position Sensor Signal Circuit	P0340, P0345, P0365, P0390	P0340, P0345, P0365, P0390	P0340, P0345, P0365, P0390	P0341, P0346, P0366, P0391
Low Reference Circuit		P0340, P0345, P0365, P0390	P0340, P0345, P0365, P0390

The 4X camshaft position sensor circuits consist of an engine control module (ECM) supplied 5 V reference circuit, low reference circuit, and an output signal circuit. The camshaft position sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes of the teeth and slots of a 4-tooth reluctor wheel attached to the camshaft. As each reluctor wheel tooth rotates past the camshaft position sensor, the resulting change in the magnetic field is used by the sensor electronics to produce a digital output pulse. The sensor returns a digital ON/OFF DC voltage pulse of varying frequency, with 4 varying width output pulses per camshaft revolution that represent an image of the camshaft reluctor wheel. The frequency of the camshaft position sensor output depends on the velocity of the camshaft. The ECM decodes the narrow and wide tooth pattern to identify camshaft position. This information is then used to determine the optimum ignition and injection points of the engine. The ECM uses the cylinder 1 intake camshaft position sensor to determine injector and ignition system synchronization. Also, the cylinder 1 intake camshaft position sensor is used to determine camshaft to crankshaft relationship, to control camshaft phasing, and for limp-home operation.

DTCs P0335, P0336, P0641, P0651, or P0697 are not set.
The engine is cranking or running.
The DTC runs continuously when the above conditions are met.

The ECM detects that the engine has started, but has received either of the following during the first engine revolution: Less than or more than 4 camshaft position sensor pulses, if equipped with an automatic transmission Less than 4 or more than 8 camshaft position sensor pulses, if equipped with a manual transmission
The ECM detects that the engine is running, but receives less than 398 camshaft position or more than 402 camshaft position sensor pulses per 100 engine cycles in 800 of 1000 engine cycles.

DTCs P0341, P0346, P0366, and P0391 are Type B DTCs.
The camshaft position actuator is commanded to the Home or Parked position.
The ignition system defaults to a failed camshaft position sensor based on the crankshaft position sensor.

DTCs P0341, P0346, P0366, and P0391 are Type B DTCs.
With a DTC set, the engine may crank for an extended period of time at start-up.

With a DTC set, the engine may crank for an extended period of time at start-up.
The cylinder 1 intake camshaft position sensor is used for injector and ignition system synchronization. A stalling condition will occur if the CMP sensor signal is intermittent and a DTC will not set. Inspect all cylinder 1 intake camshaft position sensor circuits for poor connections.

Schematic Reference

Engine Controls Schematics (LAU) or Engine Controls Schematics (LF1)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Engine Control Module Scan Tool Information (LF1,LFW) for scan tool information

If DTC P0340, P0345, P0365, or P0390 are also set, diagnose those DTCs first
With the ignition OFF, inspect the engine wiring harnesses carrying the B23 camshaft position sensor circuits for the following conditions: Close routing of aftermarket electrical equipment Close to solenoids, motors, and relays Correct any wire harness routing or component placement conditions if it is determined to be a possible source of electrical interference.
Observe the following scan tool parameters are all incrementing: Exhaust Camshaft Position Active Counter Bank 1 Intake Camshaft Position Active Counter Bank 1 Exhaust Camshaft Position Active Counter Bank 2 Intake Camshaft Position Active Counter Bank 2
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.

Engine idling, move the related harnesses/connectors of the B23 camshaft position sensor while monitoring the scan tool Camshaft Position Variance parameter. The Camshaft Position Variance parameter should not change when moving the harness/connectors. If the above condition exists, repair the harness/connectors as necessary.
Ignition OFF, inspect the B23 camshaft position sensor for correct installation. If the B23 camshaft position sensor is loose, inspect the sensor and the O-ring for damage and replace as necessary.
Disconnect the harness connector at the B23 camshaft position sensor.
Ignition OFF, all vehicle systems OFF, this may take 2 minutes, test for less than 5 ohms between the low reference circuit terminal B and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal A and ground. If 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 K20 ECM. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
Test for 4.8-5.2 V between the signal circuit terminal C and ground. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
Ignition OFF, connect a 3 A fused jumper wire to the camshaft position signal circuit terminal C.
Ignition ON, momentarily touch the end of the fused jumper wire to ground while monitoring the scan tool camshaft position active counter. The camshaft position active counter should increment. If the camshaft position active counter does not increment, replace the K20 ECM.
If all circuits test normal, replace the B23 camshaft position sensor.

Note. You must perform the Circuit/System Testing before proceeding with Component Testing.

Inspect the B23 camshaft position sensor for looseness and correct installation. Remove the camshaft position sensor from the engine and inspect the sensor and the O-ring for damage. If the sensor is loose, incorrectly installed, or damaged, repair or replace the B23 crankshaft position sensor.
Connect the camshaft position sensor connector to the camshaft position sensor. Turn ON the ignition, with the engine OFF.
Ignition ON, observe the applicable camshaft position active counter parameter with a scan tool. Pass a steel object by the tip of the sensor repeatedly. The camshaft position active counter parameter should increment. If the function does not perform as specified, replace the B23 camshaft position sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Camshaft Position Sensor Replacement - Bank 2 (Left Side) Exhaust»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Camshaft Position Sensor Replacement - Bank 2 (Left Side) Intake»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Camshaft Position Sensor Replacement - Bank 1 (Right Side) Exhaust»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Camshaft Position Sensor Replacement - Bank 1 (Right Side) Intake»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/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
Ignition Voltage	1	2
Ignition Coil 1 Control Circuit	P0300, P0351	P0300, P0351	P0300, P0351
Ignition Coil 2 Control Circuit	P0300, P0352	P0300, P0352	P0300, P0352
Ignition Coil 3 Control Circuit	P0300, P0353	P0300, P0353	P0300, P0353
Ignition Coil 4 Control Circuit	P0300, P0354	P0300, P0354	P0300, P0354
Ignition Coil 5 Control Circuit	P0300, P0355	P0300, P0355	P0300, P0355
Ignition Coil 6 Control Circuit	P0300, P0356	P0300, P0356	P0300, P0356
Low Reference		P0351, P0352, P0353, P0354, P0355, P0356
1. The Engine Cranks But Does Not Run and opens the fuse that supplies voltage to the ignition coils. 2. The Engine Cranks But Does Not Run

The ignition system on this engine uses an individual coil/module for each cylinder. The engine control module (ECM) controls the spark event for each cylinder through the eight individual ignition control circuits. When the ECM commands the ignition control circuit ON, electrical current will flow through the primary winding of the ignition coil, creating a magnetic field. When a spark event is requested, the ECM will command the ignition control circuit OFF, interrupting current flow through the primary winding. The magnetic field created by the primary winding will collapse across the secondary coil windings, producing a high voltage across the spark plug electrodes. The ECM uses information from the crankshaft position sensor, and the camshaft position sensor for sequencing and timing of the spark events.

The engine is running.
The ignition voltage is greater than 6 V.
DTC P0351-P0356 runs continuously when 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 s.

DTCs P0351-P0356 are Type B DTCs.

A high resistance condition on any ignition control circuit can cause an engine misfire without setting DTC P0351-P0356.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Engine running, observe the following scan tool control circuit status parameters for the appropriate cylinder T8 ignition coil: Ignition Coil 1-6 Control Circuit Low Voltage Test Status Ignition Coil 1-6 Control Circuit Open Test Status Ignition Coil 1-6 Control Circuit High Voltage Test Status Each parameter should display Not Run or OK.
Engine idling, observe the DTC information with a scan tool. DTC P0351, P0352, P0353, P0354, P0355, or P0356 should not set.
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.

Ignition OFF, disconnect the harness connector at the appropriate T8 ignition coil.
Ignition OFF, and all vehicle systems OFF, it may take up to 2 minutes for all the systems to power down. Test for less than 5 ohms between the ground circuit terminal A and ground. If greater than the specified range, repair the ground circuit for an open/high resistance.
Ignition OFF, test for less than 5 ohms between the low reference circuit terminal B and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit terminal D and ground. If the test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition voltage circuit fuse is open, test all components connected to the ignition voltage circuit and replace as necessary.
Engine running, observe the Ignition Coil 1-6 Control Circuit Low Voltage Test Status on the scan tool. Test Status should be OK or Not Run. If test status is Malfunction test for open or short to ground.
Engine running, observe the Ignition Coil 1-6 Control Circuit Open Test Status on the scan tool. Test Status should be OK or Not Run. If test status is Malfunction test for open circuit.
Engine running, observe the Ignition Coil 1 6 Control Circuit High Voltage Test Status on the scan tool. Test Status should be OK or Not Run. If test status is Malfunction test for short to voltage.
If all circuits test normal, test or replace the T8 ignition coil.

T8 «Ignition Coil Replacement - Bank 1»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
T8 «Ignition Coil Replacement - Bank 2»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Note. An ignition control circuit fault condition will result in an engine misfire, and under certain driving conditions could possibly overheat the 3-way catalytic converter.

Install any components or connectors that have been removed or replaced during diagnosis.
Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
Clear the DTCs.
Turn the ignition OFF for 60 s.
If the repair is related to a DTC, duplicate the Conditions for Running the DTC and use the Freeze Frame/Failure Records, if applicable, in order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) and perform the appropriate diagnostic procedure.
To verify that the performance of the catalytic converter has not been affected by the condition that set this DTC, perform the Repair Verification for DTC P0420 or P0430.

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/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
Ignition Voltage - Bank 1	P0300-P0306, P2300, P2306, P2312	P0300-P0306, P0351, P0353, P0355		P0300, P0301, P0303, P0305
Ignition Voltage - Bank 2	P0300-P0306, P2303, P2309, P2315	P0300-P0306, P0352, P0354, P0356		P0300, P0302, P0304, P0306
Ignition Coil 1 Control Circuit	P2300	P0301, P0351	P2301	P0300, P0301
Ignition Coil 2 Control Circuit	P2303	P0302, P0352	P2304	P0300, P0302
Ignition Coil 3 Control Circuit	P2306	P0303, P0353	P2307	P0300, P0303
Ignition Coil 4 Control Circuit	P2309	P0304, P0354	P2310	P0300, P0304
Ignition Coil 5 Control Circuit	P2312	P0305, P0355	P2313	P0300, P0305
Ignition Coil 6 Control Circuit	P2315	P0306, P0356	P2316	P0300, P0306
Low Reference		P0351, P0352, P0353, P0354, P0355, P0356

The ignition system on this engine uses individual ignition coils and ignition control (IC) circuits for each cylinder. Ignition voltage is supplied to each bank of ignition coils. The engine control module (ECM) controls the ignition system operation. The ECM controls each coil using the IC circuits. The ECM commands the IC circuit low when a spark event is requested.

The sequencing and timing are ECM controlled.

The engine is operating.
The ignition voltage is between 10-18 volts.
The engine speed is between 400-5,000 RPM.
The DTCs run continuously once per crankshaft revolution after the above conditions are met for 20 crankshaft revolutions.

P0351-P0356

The ECM detects the ignition control circuit is open for greater than 4 seconds or a cumulative of 30 seconds.

P2300, P2303, P2306, P2309, P2312, or P2315

The ECM detects the ignition control circuit is shorted to ground for greater than 4 seconds or a cumulative of 30 seconds.

P2301, P2304, P2307, P2310, P2313, or P2316

The ECM detects the ignition control circuit is shorted to voltage for greater than 4 seconds or a cumulative of 30 seconds.

DTCs P0351, P0352, P0353, P0354, P0355, P0356, P2300, P2301, P2303, P2304, P2306, P2307, P2309, P2310, P2312, P2313, P2315, and P2316 are Type B DTCs.

Inspect the ignition coils for aftermarket devices. An aftermarket device connected to the ignition coil circuits, may cause this DTC to set.
If the condition is intermittent, moving the related harnesses and connectors, with the engine operating, while monitoring the appropriate scan tool Misfire Current Cylinder parameter may help to isolate the condition.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/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

Operate the engine for 30 seconds. Observe the DTC information with a scan tool. DTC P0351, P0352, P0353, P0354, P0355, P0356, P2300, P2301, P2303, P2304, P2306, P2307, P2309, P2310, P2312, P2313, P2315, or P2316 should not set.
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.

Ignition OFF, disconnect the harness connector at the appropriate T8 ignition coil.
Ignition OFF, all vehicle systems OFF, it may take up to 2 minutes for all the systems to power down, test for less than 5 ohms between the ground circuit terminal A and ground. If greater than the specified range, repair the ground circuit for an open/high resistance.
Ignition OFF, test for less than 5 ohms between the low reference circuit terminal B and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
Ignition ON, verify that a test lamp illuminates between ignition voltage circuit terminal D and ground. If the test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition voltage circuit fuse is open, test all the components connected to the ignition voltage circuit and replace as necessary.
Engine running, observe the Ignition Coil 1-6 Control Circuit Low Voltage Test Status on the scan tool. Test Status should be OK or Not Run. If test status is Malfunction test for open or short to ground.
Engine running, observe the Ignition Coil 1-6 Control Circuit Open Test Status on the scan tool. Test Status should be OK or Not Run. If test status is Malfunction test for open circuit.
Engine running, observe the Ignition Coil 1-6 Control Circuit High Voltage Test Status on the scan tool. Test Status should be OK or Not Run. If test status is Malfunction test for short to voltage.
If all circuits test normal, test or replace the appropriate T8 ignition coil.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Ignition Coil Replacement - Bank 1»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Ignition Coil Replacement - Bank 2»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The secondary air injection system aids in the reduction of hydrocarbon emissions during a cold start. The electric air pump forces fresh air into the exhaust stream in order to accelerate the catalyst operation. An secondary air injection system pressure sensor is used to monitor the air flow from the secondary air injection pump. The ECM supplies voltage to the 5 V reference circuit and a ground to the low reference circuit. The sensor provides a signal voltage to the ECM relative to the pressure changes within the secondary air injection system.

Ignition voltage is supplied directly to the secondary air injection pump relay. The ECM controls the relay by grounding the control circuit, which activates the secondary air injection pump relay. With the relay contacts closed, battery voltage is supplied to the secondary air injection pump.

DTC P0100, P0101, P0102, P0103, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0119, P0418, P050C, P2227, P2228, P2229, P2257, or P2258 is not set.
Greater than 60 min has elapsed since the last cold start.
The secondary air injection system has been commanded ON and OFF during the ignition cycle.
The battery voltage is between 10-18 V.
The engine speed is between 680-3,500 RPM.
The Intake Air Temperature (IAT) is between -12 to +80°C (10.4-176°F).
The Engine Coolant Temperature (ECT) is between -10.5 to +69.8°C (13-158°F).
The Mass Air Flow (MAF) is less than 100 g/s.
Catalyst heating is active.
The Barometric Pressure (BARO) is less than 68 kPa (9.9 psi).
The difference between intake air temp and engine coolant start temp is less than 15°C (27°F).
DTC P0411 runs once per ignition cycle when the above conditions are met.

The ratio of the calculated secondary air mass flow to the modeled secondary air mass flow is less than 0.75 or greater than 1.2.
DTC P0411 sets within 60 s when the above condition is met.

DTC P0411 is a Type B DTC.

Schematic Reference

Engine Controls Schematics (LAU) or Engine Controls Schematics (LF1)

Connector End View Reference

Secondary Air Injection System Description

Description and Operation

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/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

Note. Do not run secondary air injection pump for more than 1-2 minutes at a time. Running for an extended period of time without allowing pump to cool may cause damage to the pump.

Ignition ON, observe the DTC information with a scan tool. Verify that DTC P2431, P2432, or P2433 is not set. If a DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis.
Observe the scan tool Secondary Air Injection Pressure Sensor voltage parameter. The reading should be between 1.0-4.0 V.
Compare the scan tool BARO pressure parameter to the «Altitude Versus Barometric Pressure»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-specifications__altitude-versus-barometric-pressure) table. The BARO should be within the specified range displayed in the table for the specific altitude. If not within the specified range, refer to «DTC P2227, P2228, or P2229 (LAU)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-dtc-p1516-to-dtc-p2433) for further diagnosis.
Ignition ON, command the Secondary Air Injection Pump Relay ON and OFF with a scan tool. The secondary air injection pump should turn ON and OFF.
Engine running, command the Secondary Air Injection Pump Relay ON with a scan tool while observing the Secondary Air Injection Pressure Sensor parameter. The reading should change greater than 10 kPa (1.45 psi).
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.

Inspect the secondary air injection system for the following conditions: Hoses/pipes for a restriction or blockage Hoses/pipes for being disconnected Plugged secondary air injection pressure sensor port Damaged secondary air injection check valve If a condition is located, repair as necessary. If a condition is not located and the secondary air injection pump operates with no pressure change, replace the G21 secondary air injection pump.
Ignition OFF, remove the KR25 secondary air injection pump relay.
Ignition ON, verify that a test lamp does not illuminate between the controlled output circuit terminal 30 and ground. If the test lamp illuminates, test the controlled output circuit for a short to voltage.
Verify that a test lamp illuminates between the secondary air injection pump relay switch B+ circuit terminal 87 and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the relay coil ignition circuit fuse is open, test all components connected to the ignition circuit and replace as necessary.
Connect a 20 A fused jumper wire between the secondary air injection pump relay switch B+ circuit terminal 87 and the controlled output circuit terminal 30. The G21 secondary air injection pump should turn ON. If the secondary air injection pump does not activate, test the controlled output circuit and the secondary air injection pump ground circuit for an open/high resistance. If the circuits test normal, test or replace the G21 secondary air injection pump.
If all circuits test normal, replace the KR25 secondary air injection pump relay.

Ignition OFF, disconnect the KR25 secondary air injection pump relay.
Test for 70-110 ohms between terminals 85 and 86. If the resistance is not within the specified range, replace the KR25 secondary air injection pump relay.
Test for infinite resistance between the following terminals: 86 and 87 86 and 30 85 and 87 87 and 30 If not the specified value, replace the KR25 secondary air injection pump relay.
Install a 20 A fused jumper wire between relay terminal 86 and 12 V. Install a jumper wire between relay terminal 85 and ground. Test for less than 2 ohms between terminals 87 and 30. If greater than the specified range, replace the KR25 secondary air injection pump relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Relay Replacement (Attached to Wire Harness)»(/cadillac/srx/ii-2009-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions) or «Relay Replacement (Within an Electrical Center)»(/cadillac/srx/ii-2009-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
«Secondary Air Injection Pump Replacement»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/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
Secondary Air Injection Pump Relay Coil Ignition Supply	P0418, P2257*	P0418		P0411
Secondary Air Injection Pump Relay Coil Control	P2257	P0418	P2258	P0411
*Opens the fuse that supplies voltage to the secondary air pump control relay.

The secondary air injection system aids in the reduction of hydrocarbon emissions during a cold start. The electric air pump forces fresh air into the exhaust stream in order to accelerate the catalyst operation. Ignition voltage is supplied directly to the secondary air injection pump relay. The engine control module (ECM) controls the relay 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.

The engine speed is greater than 80 RPM.
The ignition voltage is between 10-18 V.
The ECM has commanded the air pump relay ON and OFF at least once during the ignition cycle.
The DTCs run continuously when the above conditions are met.

P0418

The ECM detects the secondary air injection pump relay control circuit is open.

P2257

The ECM detects the secondary air injection pump relay control circuit is shorted to ground.

P2258

The ECM detects the secondary air injection pump relay control circuit is shorted to voltage.

DTC P0418, P2257, and P2258 are Type B DTCs.

Schematic Reference

Engine Controls Schematics (LAU) or Engine Controls Schematics (LF1)

Connector End View Reference

Secondary Air Injection System Description

Description and Operation

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/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, command the secondary air injection pump relay ON and OFF with a scan tool. You should hear an audible click or the secondary air injection pump should turn ON and OFF.
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.

Ignition OFF, remove the KR25 secondary air injection pump relay.
Ignition ON, verify that a test lamp does not illuminate between the controlled output circuit terminal 30 and ground. If the test lamp illuminates, test the controlled output circuit for a short to voltage.
Verify that a test lamp illuminates between the secondary air injection pump relay coil B+ circuit terminal 86 and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all components connected to the ignition circuit and replace as necessary.
Connect a test lamp between the control circuit terminal 85 and the secondary air injection pump relay coil B+ circuit terminal 86.
Command the secondary air injection pump relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 engine control module. If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
If all circuits test normal, test or replace the KR25 secondary air injection pump relay.

Ignition OFF, disconnect the KR25 secondary air injection pump relay.
Test for 70-110 ohms between terminals 85 and 86. If the resistance is not within the specified range, replace the KR25 secondary air injection pump relay.
Test for infinite resistance between the following terminals: 86 and 87 86 and 30 85 and 87 87 and 30 If not the specified value, replace the KR25 secondary air injection pump relay.
Install a 20 A fused jumper wire between relay terminal 86 and B+. Install a jumper wire between relay terminal 85 and ground. Test for less than 2 ohms between terminals 87 and 30. If greater than the specified range, replace the KR25 secondary air injection pump relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for engine control module replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

A 3-way catalytic converter (TWC) controls emissions of hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx). The catalyst within the converter promotes a chemical reaction, which oxidizes the HC and the CO that are present in the exhaust gas. This process converts the HC and the CO into water vapor and carbon dioxide (CO2), and reduces the NOx, converting the NOx into nitrogen. The catalytic converter also stores oxygen. The engine control module (ECM) monitors this process by using a heated oxygen sensor (HO2S) that is in the exhaust stream after the TWC. The HO2S 2 produces an output signal that the ECM uses to calculate the oxygen storage capacity of the catalyst. This indicates the ability of the catalyst to convert the exhaust emissions efficiently. The ECM monitors the efficiency of the catalyst by allowing the catalyst to heat, then wait for a stabilization period while the engine is idling. The ECM then adds and removes fuel while monitoring the HO2S 2. When the catalyst is functioning properly, the HO2S 2 response to the extra fuel is slow compared to the response of the HO2S 1, which is located before the TWC. When the HO2S 2 response is near that of the HO2S 1, the oxygen storage capability and efficiency of the catalyst may be degraded below an acceptable threshold.

LF1

DTCs P000A, P000B, P000C, P000D, P0010, P0011, P0013, P0014, P0020, P0021, P0023, P0024, P0030, P0031, P0032, P0050, P0051, P0052, P0100, P0101, P0102, P0103, P0116, P0117, P0118, P0119, P0121, P0122, P0123, P0128, P0130, P0131, P0132, P0133, P0135, P0137, P0138, P013A, P013C, P013E, P0140, P0141, P014A, P0150, P0151, P0152, P0153, P0155, P0157, P0158, P0160, P0161, P0221, P0222, P0223, P0300, P0301-P0306, P0443, P0455, P0458, P0459, P0496, P2088, P2089, P2090, P2091, P2092, P2093, P2094, P2095, P2096, P2097, P2098, P2099, P2100, P2101, P2107, P2119, P2122, P2123, P2127, P2128, P2138, P2176, P2177, P2178, P2179, P2180, P2187, P2188, P2189, P2190, P2232, P2235, P2270, P2271, P2272, or P2273 is not set.
Before the ECM performs the idle test, the vehicle must be driven under the following conditions: The engine speed is greater than 915 RPM The engine run time is greater than a calibrated value Both conditions exist for greater than 15 seconds
The throttle is in the rest position.
The intake air temperature (IAT) is between -20 to +250°C (-4 to +482°F).
The ignition voltage is greater than 11 volts.
The engine coolant temperature (ECT) is between 40-127°C (104-261°F).
The barometric pressure (BARO) is greater than 70 kPa.
The engine has been idling less than 50 seconds.
The vehicle speed is less than 2 km/h (1 mph).
The short term fuel trim is learned.
The air flow into the engine is between 3-13 g/s.
The EVAP purge concentration is learned.
The catalytic converter (TWC) calculated temperature is between 450-250°C (842-1,742°F).
The engine is operating in Closed Loop.
The transmission is not in P/N (automatic transmission only).

This diagnostic attempts one test during each valid idle period once the above conditions have been met. This diagnostic attempts up to 8 tests during each drive cycle.

LAU

DTCs P0010, P0011, P0013, P0014, P0030, P0031, P0032, P0036, P0053, P0097, P0098, P0100, P0101, P0102, P0103, P0106, P0107, P0108, P0117, P0118, P0121, P0122, P0123, P0128, P0130, P0131, P0132, P0133, P0135, P0137, P0138, P013A, P0140, P0141, P0221, P0222, P0223, P0300, P0335, P0336, P0341, P0442, P0443, P0446, P0449, P0452, P0453, P0455, P0458, P0459, P0461, P0496, P0502, P0506, P0507, P167A, P2088, P2089, P2090, P2091, P2096, P2097, P2176, P2195, P2196, P2232, P2237, P2243, P2251, P2270, P2271, P2297, P2626 are not set.
The engine speed is between 1,040-2,760 RPM.
The engine load is between 15-50 percent.
The engine is operating in Closed Loop.
The calculated exhaust mass gas flow is between 5-56 g/sec, and stable.
The calculated catalyst temperature is between 400-850°C (852-1,562°F).
The intake air temperature (IAT) is greater than -15 (5°F).

This diagnostic attempts one test during each period when the above conditions have been met. This diagnostic attempts up to 4 tests during each drive cycle.

The ECM determines that the efficiency of the catalyst has degraded below a calibrated threshold.

DTC P0420 and P0430 are Type A DTCs.

Inspect for the following conditions, which may cause a catalytic converter to degrade

An engine misfire
High engine oil or high coolant consumption
Retarded spark timing
A weak or poor spark
A lean fuel mixture
A rich fuel mixture
A damaged oxygen sensor or wiring harness

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Engine idling, observe the DTC information with a scan tool. Verify there are no HO2S or misfire DTCs set. If any of the DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) to diagnosis the applicable DTC, before proceeding with this diagnostic procedure.
Verify the following conditions do not exist with the catalytic converter: Dents A severe discoloration caused by excessive temperatures Road damage An internal rattle caused by damaged catalyst substrate Restrictions If a condition is found, replace the catalytic converter.
Verify the following conditions do not exist with the exhaust system: Leaks Physical damage Loose or missing hardware Properly torqued HO2S If a condition is found, repair the exhaust system.
Verify the following conditions do not exist with the HO2S 2: A grounded wiring harness Damage If a condition is found, replace the HO2S 2.
If no physical condition is detected and the HO2S 2 is as active as the HO2S 1 after operating the engine at 1,500 RPM for 1 minute and then returning to a stabilized idle, then replace the catalytic converter.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Exhaust Leakage»(/cadillac/srx/ii-2009-2012/remont/exhaust/#engine-exhaust-system__exhaust-leakage)
«Restricted Exhaust»(/cadillac/srx/ii-2009-2012/remont/exhaust/#engine-exhaust-system)
«Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Catalytic Converter Replacement - Left Side (LF1)»(/cadillac/srx/ii-2009-2012/remont/exhaust/#engine-exhaust-system)
«Catalytic Converter Replacement - Right Side (LF1)»(/cadillac/srx/ii-2009-2012/remont/exhaust/#engine-exhaust-system)

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine off natural vacuum test is the small leak detection diagnostic for the evaporative emission system. This diagnostic tests the evaporative emission system for a small leak when the key is turned OFF and the correct conditions are met. Heat from the exhaust system is transferred into the fuel tank while the vehicle is operating. When the vehicle is turned OFF and the evaporative emission system is sealed a change in the fuel tank vapor temperature occurs which results in a corresponding pressure change in the fuel tank vapor space. This change is monitored by the ECM using the fuel tank pressure sensor input. With a leak in the system, the amount of pressure change will be less than that of a sealed system.

DTCs P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0222, P0223, P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0455, P0461, P0462, P0463, P0464, P0496, P0502, P0503, P0608, P0641, P0651, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138 are not set.
The ignition 1 voltage is between 10-16 V.
The barometric pressure (BARO) is greater than 74 kPa.
No fuel filling during the engine off natural vacuum test period.
The fuel level is between 10-90 percent.
The start-up engine coolant temperature (ECT) and the start-up intake air temperature (IAT) are between 0-40°C (32-104°F).
The barometric pressure (BARO) is more than 74 kPa.
The engine run time before engine shut-off was greater than 10 minutes.
The drive distance before engine shut-off was more than 5 kilometers (3.1 miles).
The ignition is OFF.
The ambient air temperature at the end of the drive cycle is between 0-32°C (32-93°F).
DTC P0442 runs once per drive cycle during the hot soak period after the ignition is turned OFF and may require up to 45 minutes to complete. The controller will not make more than 2 test attempts per day. The time since the last completed engine off natural vacuum test must be at least 17 hours

The ECM detects a leak in the evaporative emission system that is greater than a calibrated amount.
The ECM must complete several engine off natural vacuum tests before the diagnostic can turn the MIL on or off.

DTC P0442 is a Type A DTC.

The evaporative emission system can be filled with smoke more quickly and completely by opening the system opposite the end where the smoke is injected. When injecting smoke at the service port remove the fuel fill cap, or temporarily leave the vent open, until smoke is observed then close the system and continue testing.
To help locate intermittent leaks using the J 41413-200: EEST, move all evaporative emission components while observing smoke with the J 41413-SPT: White Light.
Individual components can be isolated and tested using adapters in the J 41413-300: Kit.
A condition may exist where a leak in the evaporative emission system only exists under a vacuum condition. This type of leak may be detected by using the scan tool Purge/Seal function to create a vacuum in the evaporative emission system and then observe the fuel tank pressure parameter for vacuum decay.

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Description and Operation

Scan Tool Reference

Control Module References for scan tool information

Special Tools

CH 48096: Evaporative Emissions Service Access Port Tool
J 41413-200: Evaporative Emissions System Tester (EEST)
J 41413-300: Evaporative Emissions Cap and Plug Kit
J 41413-SPT: High Intensity White Light
For equivalent regional tools, refer to «Special Tools»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-special-tools-equipment) .

Note. Refer to the J 41413-200: EEST operation manual for detailed instructions in Evaporative Emission System Diagnosis . Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize. Ensure that the underbody temperature of the vehicle and the tester are similar.

Disconnect the purge tube at the quick connector on the evaporative emission canister side of the Q12 evaporative emission canister purge solenoid valve and install the CH 48096: Port Tool.
Connect the J 41413-200: EEST to the CH 48096: Port Tool.
Using a scan tool close the evaporative emission canister vent solenoid valve to seal the evaporative emission system.
Use the flow meter on the J 41413-200: EEST, calibrated to 0.51 mm (0.020 in) to determine that there is no leak in the evaporative emission system. If a leak is detected, use the J 41413-200: EEST to apply smoke to the evaporative emission system at the purge tube until the leak is located using the J 41413-SPT: White Light.

Seal the evaporative emission system and use the flow meter on the J 41413-200: EEST, calibrated to 0.51 mm (0.020 in) to determine that there is no leak in the evaporative emission system.
Clear DTCs.

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/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	High Resistance	Open	Short to Voltage
Ignition 1 Voltage - Purge Supply	P0443	P0443	P0443
Battery Positive - Vent Supply	P0449	P0449	P0449
Evaporative Emission Purge Solenoid Control	P0443	P0443	P0443	P0443
Evaporative Emission Vent Solenoid Control	P0449	P0449	P0449	P0449

An ignition voltage is supplied directly to the evaporative emission (EVAP) canister purge solenoid valve. The engine control module (ECM) grounds the evaporative emission canister purge solenoid valve control circuit through an internal switch called a driver. The ECM monitors the status of the driver. The evaporative emission canister purge solenoid valve is pulse width modulated (PWM). A scan tool will display the amount of ON time as a percentage.

Battery voltage is supplied to the EVAP canister vent solenoid valve. The ECM grounds the EVAP canister vent solenoid valve control circuit through an internal switch called a driver. The ECM monitors the status of the driver. A scan tool will display the commanded state of the evaporative emission canister vent solenoid valve as ON or OFF.

The ignition is ON.
The system voltage is between 9-18 V.
DTCs P0443 and P0449 run continuously when 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 a minimum of 5 seconds.

DTCs P0443 and P0449 are Type B DTCs.

Schematic Reference

Description and Operation

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Troubleshooting with a Test Lamp»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/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

P0443

Ignition ON, engine OFF, you should hear a clicking sound when the EVAP canister purge solenoid valve is commanded to 50 percent with a scan tool. The clicking sound should stop when the EVAP canister purge solenoid valve is commanded to 0 percent. The rate at which the valve cycles should increase when the commanded state is increased, and decrease when the commanded state is decreased.
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.

P0449

Ignition ON, engine OFF, command the EVAP vent solenoid ON and OFF with a scan tool.
Listen for a click when the valve operates. Verify that both the ON, and the OFF states are commanded.
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.

Ignition OFF, disconnect the harness connector at the Q 12 EVAP canister purge or the Q 13 EVAP vent solenoid valve.
Ignition ON, verify that a test lamp illuminates between the voltage supply circuit terminal B for vent or 1 for purge valve and ground. If the test lamp does not illuminate, test the voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and the voltage supply circuit fuse is open, test or replace the evaporative emission canister purge or vent solenoid valve.
Connect a test lamp between the voltage supply circuit terminal B for vent or 1 for purge valve and the control circuit terminal A for vent or 2 for purge valve.
Command the evaporative emission canister purge solenoid valve to 50 percent with a scan tool, or the evaporative emission canister vent solenoid valve ON and OFF. The test lamp should respond to the command. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM. If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
If all circuits test normal, replace the appropriate solenoid valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Evaporative Emission Canister Purge Solenoid Valve Replacement (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions) .
«Evaporative Emission Canister Vent Solenoid Valve Replacement (NT7, NU5)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/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
Ignition Voltage	P0443, P0458	P0443
EVAP Canister Purge Valve Control Circuit	P0458	P0443	P0459

The evaporative emission (EVAP) canister purge valve is used to purge fuel vapor from the EVAP canister to the intake manifold. The EVAP canister purge valve is pulse width modulated (PWM). Ignition voltage is supplied directly to the EVAP canister purge valve. The engine control module (ECM) controls the solenoid 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.

The engine speed is greater than 80 RPM.
The ignition voltage is between 10-18 volts.
The ECM has commanded the EVAP canister purge valve ON and OFF at least once during the ignition cycle.
The DTCs run continuously once the above conditions are met.

The ECM detects the EVAP canister purge solenoid control circuit is open. The condition exists for 4 seconds or a cumulative of 30 seconds.

P0458

The ECM detects the EVAP canister purge solenoid control circuit is shorted to ground. The condition exists for 4 seconds or a cumulative of 30 seconds.

P0459

The ECM detects the EVAP canister purge solenoid control circuit is shorted to voltage. The condition exists for 4 seconds or a cumulative of 30 seconds.

DTC P0443, P0458 and P0459 are Type B DTCs.

If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the scan tool Circuit Test Status parameter for the component. The Circuit Test Status parameter changes from OK or Not Run to Fault if there is a condition with the circuit or a connection.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/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, command the EVAP purge solenoid to 50 percent with a scan tool. You should hear an audible click.
Engine operating, observe the scan tool EVAP Purge Solenoid Circuit Test Status parameters. Verify the parameters display OK or Not Run.
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.

Ignition OFF, disconnect the harness connector at the Q12 EVAP purge solenoid.
Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit terminal 1 and ground. If the test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition voltage circuit fuse is open, test all components connected to the ignition voltage circuit and replace as necessary.
Connect a test lamp between the control circuit terminal 2 and the ignition voltage circuit terminal 1.
Command the EVAP purge solenoid to 50 percent and then to 0 percent with a scan tool. The test lamp should illuminate or flash and then go OFF. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM. If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
Test for 2.6-4.6 V between the control circuit terminal 2 and the ECM housing. If the voltage is not within the specified range, replace the K20 ECM.
If all circuits test normal, test or replace the Q12 EVAP purge solenoid.

Ignition OFF, disconnect the harness connector at the EVAP purge solenoid. Test for 15-20 ohms between the terminals of the EVAP purge solenoid. If not within the specified range, replace the Q12 EVAP purge solenoid.
Measure the resistance between each terminal of the EVAP purge solenoid and the EVAP purge solenoid housing. The DMM should display O.L. If less than the specified value, replace the Q12 EVAP purge solenoid.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Evaporative Emission Canister Purge Solenoid Valve Replacement (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions) .
«Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Typical Scan Tool Data

Fuel Tank Pressure Sensor Signal Voltage	Fuel Tank Pressure
1.5 V	Atmospheric Pressure/BARO
Less than 1.5 V	Positive Pressure
More than 1.5 V	Negative Pressure/Vacuum

This DTC tests the evaporative emission (EVAP) system for a restricted or blocked evaporative emission vent path that would cause excess amounts of vacuum to be developed in the evaporative emission system. With the purge valve open and the canister vent valve open, if the evaporative emission system vacuum goes above a calibrated threshold, the test will fail.

DTCs P0106, P0107, P0108, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0442, P0443, P0449, P0451, P0452, P0453, P0454, P0464, P0496, P0608, P0609, P0641, P0651, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138 are not set.
The ignition voltage is between 11-18 V.
The barometric pressure (BARO) is more than 74 kPa.
The fuel level is between 15-85 percent.
The engine coolant temperature (ECT) is less than 35°C (95°F).
The intake air temperature (IAT) is between 4-30°C (39-86°F).
DTC P0446 runs once per cold start when the above conditions are met.

The fuel tank vacuum is greater than 12 inches H2O vacuum for 5 seconds. OR
The fuel tank pressure is less than -2.5 inches H2O or more than +5 inches for 60 seconds after a cold start.

DTC P0446 is a Type B DTC.

An intermittent condition could be caused by a damaged evaporative emission vent housing, a temporary blockage at the evaporative emission canister vent solenoid valve inlet, or a pinched vent hose. A blockage in the vent system may also cause a poor fuel fill condition.
An evaporative emission canister filter that is restricted can cause this DTC to set.

Schematic Reference

Engine Controls Schematics (LAU) or Engine Controls Schematics (LF1)

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/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 and fuel cap removed, verify that the Fuel Tank Pressure Sensor parameter is between 1.3-1.7 volts. If not within the specified range, go to the fuel tank pressure sensor section in «Circuit/System Testing»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-dtc-p0300-to-dtc-p0455) .
Install the fuel cap.
With the engine running, the EVAP canister vent solenoid valve open, use a scan tool to command the EVAP canister purge solenoid valve to 100 percent. The fuel tank vacuum should not increase to more than -15 mm Hg (-8 inches H2O). If the fuel tank vacuum is greater than the specified range, go to the restriction section in «Circuit/System Testing»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-dtc-p0300-to-dtc-p0455) .
Using the scan tool, decrease the canister purge duty cycle from 100 percent to 0 percent. The vacuum should decrease to near zero. If the fuel tank vacuum does not return to zero or appears to decrease too slowly go to the restriction section in «Circuit/System Testing»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-dtc-p0300-to-dtc-p0455) .
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.

Note. Perform the Circuit/System Verification before proceeding with the Circuit/System Testing.

Restriction

With the engine running, the EVAP canister vent solenoid valve open, and the EVAP canister purge solenoid valve commanded to 100 percent, the fuel tank vacuum should not increase to more than -15 mm Hg (-8 inches H2O). If the fuel tank vacuum is greater than the specified value, isolate the restriction by disconnecting one component at a time while the EVAP canister purge solenoid valve is commanded to 100 percent and the vent valve is open.
Using the scan tool, decrease the canister purge duty cycle from 100 percent to 0 percent. The vacuum should decrease to near zero. If the fuel tank vacuum does not return to zero, or appears to decrease too slowly, inspect the components in the EVAP vent system for a restriction.

Fuel Tank Pressure Sensor

Ignition OFF, disconnect the harness connector at the fuel tank pressure sensor.
Ignition OFF, test for less than 5 ohms between the low reference circuit terminal and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the fuel tank pressure sensor.

«Evaporative Emission Canister Vent Solenoid Valve Replacement (NT7, NU5)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Evaporative Emission Canister Replacement (NT7, NU5)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Fuel Tank Pressure Sensor Replacement»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references)

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

With the engine running, the evaporative emission canister vent solenoid valve open and the evaporative emission canister purge solenoid valve commanded to 100 percent, the fuel tank vacuum should not increase to more than -15 mm Hg (-8 inches H2O).

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/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
Ignition Voltage	P0499	P0498
EVAP Canister Vent Solenoid Valve Control Circuit	P0498	P0449	P0499

The evaporative emission (EVAP) canister vent valve is used for EVAP system diagnostics. The EVAP canister vent valve is a normally open valve. Battery positive voltage is supplied directly to the EVAP canister vent valve. The engine control module (ECM) controls the solenoid 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. If the ECM detects the control circuit voltage is within a predetermined range when the circuit is commanded OFF, this DTC sets.

The engine speed is greater than 80 RPM.
The ignition voltage is between 10-18 volts.
The ECM has commanded the EVAP canister vent valve ON and OFF at least once during the ignition cycle.
The DTCs runs continuously once the above conditions are met.

The ECM detects the voltage on the EVAP canister vent valve control circuit is between 2.6-4.6 volts when the driver is commanded OFF. The condition exists for less than 4 seconds or for a cumulative of 30 seconds.

P0498

The ECM detects the voltage on the EVAP canister vent valve control circuit is less than 2.6 volts when the driver is commanded OFF. The condition is present for greater than 4 seconds or for a cumulative of 30 seconds.

P0499

The ECM detects the voltage on the EVAP canister vent valve control circuit is greater than 4.6 volts when the driver is commanded ON. The condition is present for greater than 4 seconds or for a cumulative of 30 seconds.

DTC P0449, P0498 and P0499 are Type B DTCs.
The EVAP system will only purge during open loop.

DTC P0449, P0498 and P0499 are Type B DTCs.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/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

Command the EVAP vent solenoid valve ON and OFF with the scan tool. An audible click should be heard when changing between the commanded states.
Start the engine, observe the DTC information with a scan tool. DTC P0449, P0498, or P0499 should not set.
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.

Ignition OFF, disconnect the harness connector at the EVAP vent solenoid valve.
Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit terminal A and ground. If the test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition voltage circuit fuse is open, test all components connected to the ignition voltage circuit and replace as necessary.
Ignition OFF, connect a test lamp between the control circuit terminal B and the ignition voltage circuit terminal A.
Ignition ON, use a scan tool to command the EVAP vent solenoid valve ON and OFF. The test lamp should turn ON and OFF. If the test lamp remains ON all the time, test for a short to ground on the control circuit. If circuit/connections test normal, replace the ECM. If the test lamp remains OFF all the time, test for a short to voltage or an open/high resistance on the control circuit. If circuit/connections test normal, replace the K20 ECM.
Test for 2.6-4.6 volts between the control circuit terminal B and ground. If the voltage is not within the specified range, replace the K20 ECM.
If all circuits/connections test normal, test or replace the Q13 EVAP vent solenoid valve.

Test for 20-24 ohms between the terminals of the Q13 EVAP vent solenoid valve. If not within the specified range, replace the Q13 EVAP vent solenoid valve.
Test for infinite resistance between each terminal of the EVAP vent solenoid valve and the EVAP vent solenoid valve housing. If not the specified value, replace the Q13 EVAP vent solenoid valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Evaporative Emission Canister Vent Solenoid Valve Replacement (NT7, NU5)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/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	Short to Voltage
Operating Conditions: Engine operating in Closed Loop at idle Parameter Normal Range: 0.2-4.8 V
5-Volt Reference Voltage	0 V	0 V	5 V
Fuel Tank Pressure Sensor Signal	0 V	0 V	5 V
Low Reference		4.2 V

Fuel Tank Pressure Sensor

The control module monitors the fuel tank pressure sensor signal in order to detect vacuum decay and excess vacuum during the evaporative emission (EVAP) diagnostic test. The control module supplies a 5-volt reference and a low reference circuit to the fuel tank pressure sensor. This DTC sets if the engine control module (ECM) detects one of the following conditions

The fuel tank pressure sensor signal voltage is not within a calibrated range on a cold start-up.
The fuel tank pressure sensor signal oscillates greater than a calibrated amount when vehicle speed is within a predetermined range.

The following table illustrates the relationship between fuel tank pressure sensor signal voltage and the EVAP system pressure/vacuum.

Fuel Tank Pressure Sensor Signal Voltage	Fuel Tank Pressure
High, Approximately 1.5 Volts or More	Negative Pressure/Vacuum
Low, Approximately 1.5 Volts or Less	Positive Pressure

P0450

DTC P0100, P0101, P0102, P0103, P0116, P0117, P0118, P0119, P0443, P0449, P0458, P0459, P0498, P0499, P050A, P0506, P0507, P0700, P2227, P2228, or P2229 is not set.
The engine is operating.
The ambient air temperature is greater than -7°C (+19°F).
The vehicle speed is less than 31 km/h (19 mph).
The ECM has commanded the EVAP canister vent valve open for greater than 3 seconds, 4 seconds for LLT.
DTC P0450 runs continuously once the above conditions are met for approximately 25 seconds.

P0451 Condition 1

DTC P0100, P0101, P0102, P0103, P0116, P0117, P0118, P0119, P0443, P0449, P0458, P0459, P0498, P0499, P050A, P0506, P0507, P0700, P2227, P2228, or P2229 is not set.
The engine is operating for greater than 1 second.
The engine is idling.
The ambient air temperature is greater than -7°C (+19°F).
The vehicle speed is less than 10 km/h (6 mph) for greater than 29 seconds.
The BARO is greater than 68 kPa.
The fuel level is between 11-88 percent.
The ECM has commanded the EVAP canister purge solenoid ON.
The ECM has commanded the EVAP canister vent valve closed for greater than 4 seconds.
DTC P0451 runs continuously when the above conditions are met for approximately 25 seconds.

P0451 Condition 2

DTC P0100, P0101, P0102, P0103, P0116, P0117, P0118, P0119, P0443, P0449, P0458, P0459, P0498, P0499, P050A, P0506, P0507, P0700, P2227, P2228, or P2229 is not set.
The engine is operating.
The BARO is greater than 68 kPa.
The fuel level is between 11-88 percent.
The ECM has commanded the EVAP canister purge solenoid OFF.
The ECM has commanded the EVAP canister vent valve open. OR
The fuel level is less than 60 percent, 73 percent for LLT.
The vehicle speed is between 10-76 km/h (6-47 mph) for greater than 30 seconds.
The ECM has commanded the EVAP canister purge solenoid ON. OR
The calculated ambient air temperature is between 4-35°C (39-95°F) for greater than 3 seconds.
DTC P0451 runs continuously when the above conditions are met for approximately 7 seconds.

The ECM detects that the FTP sensor signal oscillates greater than 6.09 mm/Hg (3.26 in. H2O) for 4 seconds, or for a cumulative of 30 seconds.

P0451

The ECM detects that the fuel tank pressure is less than -26.2 mm/Hg (-14.1 in. H2O) or greater than 11.0 mm/Hg (5.9 in. H2O) for 4 seconds or for a cumulative of 30 seconds. OR
The ECM detects a change in the zero point of fuel tank pressure sensor signal greater than +/-5.16 mm/Hg (2.76 in. H2O) from the zero point at start up for 4 seconds, or a cumulative of 30 seconds.

DTCs P0450 and P0451 are Type B DTCs.

A blocked or clogged EVAP canister vent may set these DTCs.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/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

Special Tools

J 41413-SPT High Intensity White Light. See «Special Tools»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-special-tools-equipment) .
J 41413-VLV EVAP Port Vent Fitting Tool. See «Special Tools»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-special-tools-equipment) .
J 41413-200 Evaporative Emissions System Tester (EEST). See «Special Tools»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-special-tools-equipment) .
J 41413-300 EVAP Cap and Plug Kit
CH-48096 EVAP Service Port Access Tool. See «Special Tools»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-special-tools-equipment) .
GE-41415-50 Fuel Tank Cap Adapter

Ignition OFF, remove the fuel fill cap. Connect the GE-41415-50 to the fuel tank filler neck. Connect the J 41413-200 to the GE-41415-50 . See «Special Tools»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-special-tools-equipment) .
Ignition ON, seal the system using the Purge Seal function with a scan tool.
Pressurize the EVAP system with nitrogen to 9.33 mm/Hg (5 in. H2O). Compare the scan tool Fuel Tank Pressure Sensor parameter to the J 41413-200 pressure/vacuum gauge. See «Special Tools»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-special-tools-equipment) . Verify the fuel tank pressure sensor parameter is within +/-0.9 mm Hg (+/-0.5 in. H2O) of the pressure/vacuum gauge. If not within the specified range, replace the B150 fuel tank pressure sensor.
Command the EVAP vent solenoid valve OPEN with a scan tool. Verify the scan tool Fuel Tank Pressure Sensor parameter is -0.9 to +0.9 mm Hg (-0.5 to +0.5 in. H2O). If not within the specified range, replace the B150 fuel tank pressure sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Fuel Tank Pressure Sensor Replacement

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/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	High Resistance	Open	Short to Voltage	Signal Performance
Fuel Tank Pressure Sensor 5V Reference	P0452, P0532, P0641	P0451	P0446, P0452	P0453, P0641
Fuel Tank Pressure Sensor Signal	P0452	P0451	P0452	P0453	P0451, P0454
Fuel Tank Pressure Sensor Low Reference		P0446, P0451	P0446		P0451

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Ignition ON, Engine OFF Parameter Normal Range: 1.3-1.7 V
Fuel Tank Pressure Sensor 5V Reference	0 V	0 V	4.2-5 V
Fuel Tank Pressure Sensor Signal	0 V	0 V	5 V
Fuel Tank Pressure Sensor Low Reference		4.5 V

Fuel Tank Pressure Sensor Voltage

The fuel tank pressure sensor measures air pressure or vacuum in the evaporative emission (EVAP) system. The engine control module (ECM) supplies a 5V reference and a low reference circuit to the fuel tank pressure sensor. The fuel tank pressure sensor signal voltage varies depending on EVAP system pressure or vacuum. The controller also uses this fuel tank pressure signal to determine atmospheric pressure for use in the engine-off small leak test, DTC P0442. Before using this signal as an atmospheric reference it must first be re-zeroed.

DTC P0451 runs only when the engine-off natural vacuum small leak test, P0442, executes.
The number of times this test runs can range from 0-2 per engine-off period. The length of the test can be up to 10 minutes.

P0452 and P0453

DTC P0452 and P0453 run continuously when the ignition is ON.

P0454

DTC P0454 runs only when the engine-off natural vacuum small leak test, P0442, executes.
This test can run once per engine-off period. The length of the test can be up to 10 minutes.
A refueling event is not detected.

This DTC will set if the controller is unable to re-zero the fuel tank pressure sensor voltage within a calibrated range during the engine-off small leak test, P0442.

P0452

The fuel tank pressure sensor voltage is less than 0.1V for more than 5 seconds.

P0453

The fuel tank pressure sensor voltage is more than 4.9V for more than 5 seconds.

If, during the engine-off natural vacuum small leak test, P0442, the ECM detects an abrupt fuel tank pressure signal change, other than a refueling event, this DTC will set. An abrupt change is defined as a change of 0.45 inch H2O in the span of 1 second.

DTCs P0451 and P0454 are Type A DTCs.
DTCs P0452 and P0453 are Type B DTCs.

DTCs P0451 and P0454 are Type A DTCs
DTCs P0452 and P0453 are Type B DTCs

P0451 and P0454

A restriction in the EVAP canister or vent lines could prevent fuel vapor pressure from bleeding off fast enough. If the vent system cannot bleed off pressure fast enough, the re-zero procedure may not complete successfully, which could cause this code to set.
Ensure that the reference port on the fuel tank pressure sensor is unobstructed.
An fuel tank pressure sensor that is skewed or does not have a linear transition from low to high may cause this code to set. Scan tool output controls, snapshot, and plot functions can help detect erratic sensor response. To test the sensor signal under vacuum conditions, use the Quick Snapshot and the Purge/Seal functions to capture data while commanding purge to 20 percent, then plot the data to look for erratic sensor operation. A similar test can be done for the pressure side of the sensor operation by applying pressure with the J 41413-200: EEST while taking a snapshot.

Schematic Reference

Connector End View Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/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

Special Tools

J 41413-200: Evaporative Emission System Tester (EEST)

Remove the fuel cap.
Ignition ON, engine OFF.
Observe the Fuel Tank Pressure Sensor parameter with a scan tool.
The Fuel Tank Pressure Sensor parameter should be 1.3-1.7 V.

Ignition OFF, disconnect the harness connector at the B150 fuel tank pressure sensor.
Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal 2 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
Ignition ON, test for 4.8-5.2V between the 5V reference circuit terminal 3 and ground. If less than the specified range, test the 5V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM. If greater than the specified range, test the 5V reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
Verify the scan tool B150 fuel tank pressure sensor parameter is less than 0.2V. If greater than the specified range, test the signal circuit terminal 1 for a short to voltage. If the circuit tests normal, replace the K20 ECM.
Install a 3A fused jumper wire between the signal circuit terminal 1 and the 5V reference circuit terminal 3. Verify the scan tool fuel tank pressure sensor parameter is greater than 4.7V. If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
If all circuits test normal, test or replace the B150 fuel tank pressure sensor.

«Fuel Tank Pressure Sensor Replacement»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
For DTC P0452 or P0453, always perform the «Diagnostic Repair Verification»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-repair-verification) after completing the diagnostic procedure.
For DTC P0451 or P0454, clear DTCs with a scan tool.
«Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/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
5-Volt Reference	P0122, P0452, P0642	P0452, P0641	P0453, P0643	P0641, P0642, P0643
Fuel Tank Pressure Sensor Signal	P0452	P0452	P0453
Low Reference		P0446

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Engine operating in Closed Loop at idle Parameter Normal Range: 0.2-4.8 V
5-Volt Reference	0 V	0 V	5 V
Fuel Tank Pressure Sensor Signal	0 V	0 V	5 V
Low Reference		4.2 V

Fuel Tank Pressure Sensor

The evaporative emission (EVAP) system is used to store fuel vapors in order to reduce the amount of fuel vapors into the atmosphere. The fuel tank pressure sensor is only used for EVAP system diagnostics. The fuel tank pressure sensor is a transducer that varies resistance according to changes in the fuel tank pressure. The engine control module (ECM) monitors the fuel tank pressure sensor signal in order to detect vacuum decay and excess vacuum during the EVAP system diagnostic test. The ECM supplies a 5-volt reference and a low reference circuit to the fuel tank pressure sensor.

Fuel Tank Pressure Sensor Signal Voltage	Fuel Tank Pressure
High, Approximately 1.5 Volts or More	Negative Pressure/Vacuum
Low, Approximately 1.5 Volts or Less	Positive Pressure

The engine is operating.
The DTCs run continuously once the above conditions are met for 14 seconds, 10 seconds for LLT.

The ECM detects the fuel tank pressure sensor signal voltage is less than 0.12 volt for 4 seconds, or a cumulative of 30 seconds.

The ECM detects the fuel tank pressure sensor signal voltage is greater than 4.85 volts for 4 seconds, or a cumulative of 30 seconds.

DTC P0452 and P0453 are Type B DTCs.

If a shared 5-volt reference circuit is shorted to ground or shorted to a voltage, other 5-volt reference circuits may be affected.

Schematic Reference

Connector End View Reference

Description and Operation

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Electrical Information Reference

«Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
«Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
«Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
«Wiring Repairs»(/cadillac/srx/ii-2009-2012/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, observe the DTC information with a scan tool. DTC P0641, P0642 or P0643 should not be set. If a DTC is set, refer to «DTC P0641-P0643, P0651-P0653, or P0697-P0699 (ECM, LAU)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-dtc-p0455-to-dtc-p150cp1400) .
Observe the Fuel Tank Pressure Sensor voltage parameter. The Fuel Tank Pressure sensor voltage should be between 0.13-4 volts.
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.

Ignition OFF, disconnect the harness connector at the B150 fuel tank pressure sensor.
Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal 1 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
Ignition ON, test for 4.8-5.2V between the 5V reference circuit terminal 3 and ground. If less than the specified range, test the 5V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM. If greater than the specified range, test the 5V reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
Verify the scan tool B150 fuel tank pressure sensor parameter is less than 0.2V. If greater than the specified range, test the signal circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the K20 ECM.
Install a 3A fused jumper wire between the signal circuit terminal 2 and the 5V reference circuit terminal 3. Verify the scan tool fuel tank pressure sensor parameter is greater than 4.7V. If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
If all circuits test normal, test or replace the B150 fuel tank pressure sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

«Fuel Tank Pressure Sensor Replacement»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
«Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The ECM tests the evaporative emission (EVAP) system for a large leak or restrictions to the purge path in the evaporative emission system. When the enabling criteria has been met the ECM commands the EVAP canister vent solenoid valve ON and the EVAP canister purge solenoid valve ON, allowing vacuum into the evaporative emission system. The ECM monitors the fuel tank pressure sensor voltage to verify that the system is able to reach a predetermined level of vacuum within a set amount of time.

Before the ECM can report DTC P0455 failed, DTC P0496 must run and pass.
DTCs P0106, P0107, P0108, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0442, P0443, P0449, P0451, P0452, P0453, P0454, P0464, P0496, P0608, P0609, P0641, P0651, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138 are not set.
The ignition voltage is between 11-18 V.
The barometric pressure (BARO) is more than 74 kPa.
The fuel level is between 10-90 percent.
The engine coolant temperature (ECT) at start-up is less than 35°C (95°F).
The intake air temperature (IAT) is between 4-30°C (39-86°F).
DTC P0455 runs once per cold start when the above conditions are met.

The EVAP system is not able to achieve or maintain a calibrated level of vacuum within a set amount of time.

DTC P0455 is a Type B DTC.

Inspect for a loose, missing, damaged, or incorrect fuel fill cap.
Inspect for a damaged fuel filler neck seal surface.
A blockage or restriction in the evaporative emission purge solenoid valve, purge pipe, evaporative emission canister, or vapor pipe, can cause this DTC to set.
The evaporative emission system can be filled with smoke more quickly and completely by opening the system opposite the end where the smoke is injected. For example, when injecting smoke at the service port remove the fuel fill cap, or temporarily leave the vent open, until smoke is observed, then close the system and continue testing.
To help locate intermittent leaks using the J 41413-200: EEST, move all evaporative emission components while observing smoke with the J 41413-SPT: White Light.
Individual components can be isolated and tested using adapters in the J 41413-300: Kit.
A condition may exist where a leak in the EVAP system only exists under a vacuum condition. This type of leak may be detected by using the scan tool EVAP Purge/Seal function to create a vacuum in the EVAP system and then observe the fuel tank pressure parameter for vacuum decay.

Schematic Reference

Connector End View Reference

Description and Operation