Engine Controls - Self Diagnostics - 8.1L: Diagnosis Chevrolet Silverado 1500 HD

ON-BOARD DIAGNOSTICS

PCM is equipped with a self-diagnostic system which detects system failures or abnormalities. When a malfunction occurs, PCM will store a Diagnostic Trouble Code (DTC) and, in most cases, illuminate the Malfunction Indicator Light (MIL) located on instrument cluster.

There are 2 paths for accessing on-board diagnostics. It is necessary to access information through both paths, as each path presents some different information.

1. Generic OBD-II This provides all generic codes and some OEM codes, serial data PIDs required for generic OBD-II and some OEM PIDs, monitor status, pending codes and freeze frame.
2. OEM All DTCs, all PIDs, failure records, enhanced scan tool information and all other OEM scanner functions.

Scan Tool Snapshot

The scan tool can be set up to take a snapshot of the parameters available via serial data. The snapshot function records live data over a period of time. The recorded data can be played back and analyzed. The scan tool can also graph parameters singly or in combinations of parameters for comparison. The snapshot can be triggered manually at the time the symptom is noticed, or set up in advance to trigger when a DTC sets. An abnormal value captured in the recorded data may point to a system or component that needs to be investigated further. Refer to the scan tool user instructions for more information on the Snapshot function.

DIAGNOSTIC STARTING POINT - ENGINE CONTROLS

Diagnosis of computerized engine control system should be performed in the following order

1. Ensure all engine systems not related to computer system are operating properly. DO NOT proceed with testing unless all other problems have been repaired. Diagnostic system check must be performed before using specific DTC testing procedure. See «DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS»(ref-158433-S21464854222003092600000) .
2. If no DTCs are present and a driveability problem exists, see «SYMPTOMS»(ref-153006-S25129811232003031000000) in TROUBLE SHOOTING - NO CODES - 8.1L AVALANCHE, SIERRA, SILVERADO, SUBURBAN & YUKON XL article. Doing so will help identify proper system or component to check in «SYSTEM & COMPONENT TESTING - 8.1L AVALANCHE, SIERRA, SILVERADO, SUBURBAN & YUKON XL»(ref-153339) article.
3. After necessary repairs are made, clear DTCs, verify vehicle will enter "closed loop" operation and ensure DTC does not reset.

Diagnostic Procedure

Note. Do not perform this diagnostic if there is not a driveability concern, unless another procedure directs you to this diagnostic. Before you proceed with diagnosis, search for applicable service bulletins. Unless a diagnostic procedure instructs you, do NOT clear the DTCs. If there is a condition with the starting system, see appropriate STARTERS article in ELECTRICAL. Ensure the battery has a full charge. Ensure the battery cables are clean and tight. Ensure the PCM grounds are clean, tight, and in the correct location.

1. Install a scan tool. Does the scan tool turn ON? If yes, go to next step. If no, see SCAN TOOL DOES NOT POWER UP in appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
2. Turn ON the ignition, with the engine OFF. Attempt to establish communication with the listed control modules. If you are using a Tech 2®, obtain the information using the Class 2 Message Monitor feature: PCM. Body Control Module (BCM). Instrument Panel (IP) cluster. Electronic Brake Control Module (EBCM). Driver Information Center (DIC). Heating, Ventilation, and Air Conditioning (HVAC). Does the scan tool communicate with all the listed control modules? If yes, go to next step. If no, see SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE in appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
3. Access CLASS 2 POWER MODE in DIAGNOSTIC CIRCUIT CHECK on scan tool. Rotate ignition switch through all positions while observing IGNITION SWITCH POWER MODE parameter. Actual ignition switch position should match IGNITION SWITCH POWER MODE parameter on scan tool. (Scheme 629) Do all ignition switch positions match all IGNITION SWITCH POWER MODE parameters on scan tool? If yes, go to next step. If no, see «POWER MODE MISMATCH»(ref-158433-S26691094852003102400000).
4. Attempt to start the engine. Does the engine start and idle? If yes, go to next step. If no, see «SYMPTOMS»(ref-153006-S25129811232003031000000) in TROUBLE SHOOTING - NO CODES - 8.1L AVALANCHE, SIERRA, SILVERADO, SUBURBAN & YUKON XL article.
5. Select the DTC display function for the following control modules: PCM, BCM, IP Cluster, EBCM, DIC and HVAC. Does the scan tool display any DTCs? If yes, go to next step. If no, go to step 10.
6. Using a scan tool, select CAPTURED INFO in order to store the powertrain DTC information. When complete, go to next step.
7. Does the scan tool display DTCs which begin with a "U"? If yes, see appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT for diagnosis. If no, go to next step.
8. Does the scan tool display DTC P0601, P0602, P0604 or P0606? If yes, see «DTC P0601-P0607, P1600, P1621, P1627, P1680, P1681 & P1683: PCM MEMORY»(ref-158433-S15595344342003092600000) under DIAGNOSTIC TESTS. If no, go to next step.
9. Does the scan tool display DTC P0562, P0563, P1637 or P1638? If yes, see appropriate GENERATORS & REGULATORS article in ELECTRICAL. If no, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-158433-S36149293242003092600000).
10. Is the customer's concern with the automatic transmission? If yes, see appropriate DIAGNOSIS article in AUTOMATIC TRANSMISSIONS. If no, go to next step.
11. Is the customer's concern with Inspection and Maintenance (I/M) testing? If yes, see «INSPECTION/MAINTENANCE SYSTEM CHECK»(ref-158433-S34044282112003092600000) under DRIVE CYCLES.
12. Review the following symptoms. Hard start, surges/chuggles, lack of power, sluggishness, sponginess, detonation/spark knock, hesitation, sag, stumble, cuts out, misses, poor fuel economy, poor fuel fill quality, rough, unstable, or incorrect idle and stalling, dieseling, run-on and backfire. See «SYMPTOMS»(ref-153006-S25129811232003031000000) in TROUBLE SHOOTING - NO CODES - 8.1L AVALANCHE, SIERRA, SILVERADO, SUBURBAN & YUKON XL article. Did you find and correct the condition? If yes, system is okay. If no, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000).

1. The Diagnostic System Check will provide the following information: The identification of the control module(s) which command the system. The ability of the control module(s) to communicate through the serial data circuit. The identification of any stored Diagnostic Trouble Codes (DTCs) and their status. The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located.
2. Install a scan tool. Does the scan tool turn ON? If yes, go to next step. If no, see SCAN TOOL DOES NOT POWER UP in appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
3. Turn ON the ignition, with the engine OFF. Attempt to establish communication with the PCM. If you are using a Tech 2®, obtain the information using the Class 2 Message Monitor feature. Does the scan tool communicate with the PCM? If yes, go to next step. If no, see SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE in appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
4. Select the Powertrain Control Module display DTCs function on the scan tool. Does the scan tool display any DTCs? If yes, go to next step. If no, see «COOLING SYSTEM TROUBLE SHOOTING»(ref-27342-S11025938142001112800000) under ENGINE MECHANICAL in TROUBLE SHOOTING - BASIC PROCEDURES article in GENERAL INFORMATION.
5. Does the scan tool display DTCs which begin with a "U"? If yes, see appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT for diagnosis. If no, go to next step.
6. See «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-158433-S36149293242003092600000) .

Note. This procedure is used if the observed vehicle power mode does not match the actual ignition switch position. Open the driver's door and leave it open during this test. This will disable the RAP power mode and eliminate this power mode from the power mode parameter list.

1. Connect a scan tool to Data Link Connector (DLC). Turn OFF the ignition. Using a scan tool, under the DIAGNOSTIC CIRCUIT CHECK menu, observe the CLASS 2 POWER MODE parameter. Does the displayed power mode parameter match the actual ignition switch position? If yes, go to next step. If no, go to step 6 .
2. Turn the ignition switch to the UNLOCK position. Using a scan tool, under the DIAGNOSTIC CIRCUIT CHECK menu, observe the CLASS 2 POWER MODE parameter. Does the displayed power mode parameter match the actual ignition switch position? If yes, go to next step. If no, go to step 6 .
3. Turn ON the ignition, with the engine OFF. Using a scan tool, under the DIAGNOSTIC CIRCUIT CHECK menu, observe the CLASS 2 POWER MODE parameter. Does the displayed power mode parameter match the actual ignition switch position? If yes, go to next step. If no, go to step 6 .
4. Turn the ignition switch to the CRANK position. Using a scan tool, under the DIAGNOSTIC CIRCUIT CHECK menu, observe the CLASS 2 POWER MODE parameter. Does the displayed power mode parameter match the actual ignition switch position? If yes, go to next step. If no, go to step 6 .
5. Turn the ignition switch to the ACCY position. Using a scan tool, under the DIAGNOSTIC CIRCUIT CHECK menu, observe the CLASS 2 POWER MODE parameter. Does the displayed power mode parameter match the actual ignition switch position? If yes, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) . If no, go to next step.
6. Turn OFF the ignition. Disconnect the BCM. Hold the ignition switch in the position that indicated the incorrect power mode. Using a test light connected to a good ground, test the BCM ignition switch inputs for voltage. See BODY CONTROL MODULES in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Is voltage present on only the inputs specified for the ignition switch position? If yes, go to next step. If no, go to step 8 .
7. Hold the ignition switch in the position that indicated the incorrect power mode. Using a test light connected to a good ground, test the BCM ignition switch inputs for voltage. See BODY CONTROL MODULES in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If voltage does not exist on any inputs specified for the ignition switch position, go to step 9 . If voltage exists on any inputs specified for the ignition switch position, go to step 11 .
8. Disconnect the ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. Test the BCM ignition switch input circuits for a short to voltage. Test the BCM ignition switch circuits for a short between circuits. See BODY CONTROL MODULES in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Did you find and correct the condition? If yes, go to step 14 . If no, go to step 10 .
9. Disconnect the ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. Test the BCM ignition switch input circuits for an open. See BODY CONTROL MODULES in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Did you find and correct the condition? If yes, go to step 14 . If no, go to next step.
10. Inspect for poor connections and terminal tension at the harness connector of the ignition switch. Did you find and correct the condition? If yes, go to step 14 . If no, go to step 12 .
11. Inspect for poor connections and terminal tension at the harness connector of the BCM. Did you find and correct the condition? If yes, go to step 14 . If no, go to step 13 .
12. Replace the ignition switch. See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT. After ignition switch replacement, go to step 14 .
13. Replace the BCM. See appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT. After BCM replacement, go to next step.
14. Reconnect all disconnected components and connectors. Using a scan tool, under the DIAGNOSTIC CIRCUIT CHECK menu, observe the CLASS 2 POWER MODE parameter. Cycle the ignition switch through all possible positions, one at a time. Does the displayed power mode parameter match the actual ignition switch position? If yes, system is okay. If no, go to step 1 .

RETRIEVING DIAGNOSTIC TROUBLE CODES

DTCs are retrieved using a Tech 2® scan tool, or other OBD-II compatible scan tool connected to OBD-II 16-pin Data Link Connector (DLC). See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS . DLC is located below left side of dash.

CLEARING DIAGNOSTIC TROUBLE CODES

There are 3 methods to clear DTCs.

Scan Tool

Scan tool is preferable way to clear DTC information. Freeze frame and failure record data will also be cleared.

Diagnostic Aids

The I/M System Status display provides an indication of when the control module has completed the required tests. This does not necessarily mean that the test has passed, only that a decision was made. If the diagnostic fails, a DTC will indicate the failure. If a failure indication is present for a DTC associated with one of the I/M regulated systems, the failure indication may prevent other required tests from running. For example, a DTC for the control circuit of the relay controlling an AIR pump may not be listed in the INSPECTION/MAINTENANCE SYSTEM DTCS table because this is a continuous test. If this DTC is set, the Active Tests for the AIR system may not run. The I/M System Status information may be useful for a technician to determine if diagnostics have run when verifying repairs.

Conditions for Running

Cold Start

1. The Barometric (BARO) pressure is more than 74 kPa.
2. The Engine Coolant Temperature (ECT) is below 86°F (30°C).
3. The Intake Air Temperature (IAT) is below 86°F (30°C).
4. The difference between the Intake Air Temperature (IAT) and the Engine Coolant Temperature (ECT) is 14°F (8°C) or less.
5. The battery voltage is between 9-18 volts.
6. The fuel level is between 1/4 and 3/4.

Rough road conditions may prevent some of the tests from running. Extreme high or low ambient temperatures may prevent tests such as Heated Oxygen Sensor (HO2S) Heater and Evaporative (EVAP) emission System from initiating. If a step is interrupted before completion, perform the remaining portion of the set procedures. Any portion of the set procedure that requires the engine at operating temperature may be repeated. This allows most of the diagnostics to run and the remaining tests can be performed using the individual System Set Procedures. If the vehicle has recently run, start this procedure at step 3 . This will allow the tests that require the engine at operating temperature to run. Using this method allows shorter cool down periods if the tests requiring a cold start do not initiate. The scan tool can be used to monitor each of the I/M System Status indicators during the I/M Complete System Set Procedure. When all of the indicators for a test step have updated to YES, testing can move on to the next step even if the remaining portion of the test is not complete. For example, step 3 is designed to run the EVAP, secondary Air Injection (AIR), and HO2S tests. The procedure instructs the technician to operate the vehicle in the enable conditions for 6 minutes. If all 3 tests have updated to YES within 4 minutes, it is not necessary to continue with the enable conditions and testing can advance to the next step.

INSPECTION/MAINTENANCE SYSTEM DTCS

1. The Barometric (BARO) pressure is more than 74 kPa.
2. The engine coolant is at operating temperature, 160-248°F (71-120°C).
3. The Intake Air Temperature (IAT) is between 5-167°F (-15 to 75°C).
4. The engine is in Closed Loop fuel control.
5. The engine has run for 6-8 minutes off idle in order to initiate test.
6. The battery voltage is between 11-18 volts.

The control module runs a maximum of 6 tests per trip until the Catalyst System Status updates to YES. If the status does not update, the test outlined in this procedure can be repeated until the I/M System Status updates to YES. The I/M System Status does not indicate whether the test has passed or failed, only that a decision was made. When all of the diagnostics for a specific system have run and passed, the I/M System Status will update to YES. If a test for a specific system has failed, the I/M System Status will update to YES, indicating a determination was made, even if all of the required tests have not run. When a failure occurs, the Emission Related DTC portion of the I/M System Status display will indicate the Malfunction Indicator Lamp (MIL) is requested. The I/M System Status also registers the number of diagnostic trouble codes (DTCs). The first failure of a type "B" DTC does not constitute a final determination of pass or fail, and will not update the I/M System Status to YES. A second trip is required, and all the conditions to run must be met in order for the test to run again. These conditions may include a partial to complete engine cool down. The I/M System Status will update only when an emission related DTC fails the second time, or when all of the tests pass. If there is an impending failure, the system may require more time to run the diagnostic than was allotted in the set procedure. If the test does not run after numerous attempts and no DTC is set, review the appropriate scan tool data list and the service information for an indication of why the test does not complete. Some tests may abort due to changes in the conditions while the test is running. For example, changes in engine load, such as a cooling fan or an A/C compressor clutch turning ON, may cause the test to abort. If a diagnostic test is difficult to run, observe the I/M System Status display while maintaining the necessary enable conditions until the system status updates to YES.

1. DTCs P0442, P0446, P0455, P0496 are not set.
2. The barometric pressure is more than 75 kPa.
3. The fuel level is between 1/4 and 3/4.
4. The battery voltage is between 10-18 volts.
5. The Engine Coolant Temperature (ECT) is between 39-86°F (3.8-30°C).
6. The Intake Air Temperature (IAT) is between 39-86°F (3.8-30°C).
7. The difference between the ECT and the IAT is less than 14°F (8°C).

If there is an impending failure, the system may require more time to run the diagnostic than was allotted in the set procedure. If the test does not run after numerous attempts and no DTC is set, review the appropriate scan tool data list and the service information for an indication of why the test does not complete. Some tests may abort due to changes in the conditions while the test is running. For example, changes in engine load such as cooling fan or an A/C compressor clutch turning ON may cause the test to abort.

1. The Engine Coolant Temperature (ECT) is more than 135°F (57°C).
2. The engine is running in Closed Loop fuel control.
3. The engine has been running for more than 160 seconds.
4. The battery voltage is between 10-18 volts.

If the status does not update, the test outlined in this procedure can be repeated until the I/M System Status updates to YES. The I/M System Status does not indicate whether the test has passed or failed, only that a decision was made. When all of the diagnostics for a specific system have run and passed, the I/M System Status will update to YES. If a test for a specific system has failed, the I/M System Status will update to YES, indicating a determination was made, even if all of the required tests have not run. When a failure occurs, the Emission Related DTC portion of the I/M System Status display will indicate the Malfunction Indicator Lamp (MIL) is requested. The I/M System Status also registers the number of diagnostic trouble codes (DTCs). The first failure of a type "B" DTC does not constitute a final determination of pass or fail, and will not update the I/M System Status to YES. A second trip is required, and all the conditions to run must be met in order for the test to run again. These conditions may include a partial to complete engine cool down. The I/M System Status will update only when an emission related DTC fails the second time, or when all of the tests pass. If there is an impending failure, the system may require more time to run the diagnostic than was allotted in the set procedure. If the test does not run after numerous attempts and no DTC is set, review the appropriate scan tool data list and the service information for an indication of why the test does not complete. Some tests may abort due to changes in the conditions while the test is running. For example, changes in engine load, such as a cooling fan or an A/C compressor clutch turning ON, may cause the test to abort. If a diagnostic test is difficult to run, observe the I/M System Status display while maintaining the necessary enable conditions until the system status updates to YES.

1. The start up Engine Coolant Temperature (ECT) is more than 140°F (60°C).
2. The battery voltage is between 10-18 volts.

The HO2S heater tests will normally run within the 2 minutes allotted in the procedure. If there is an indeterminate condition, the test may take up to 8 minutes on some vehicles before a decision of pass or fail is made. If the test does not update within the allotted period of time, continue operation within the enable conditions until the test updates to YES. If the test does not update to YES, the test may have failed or aborted due to the loss of enabling conditions. Extremely high ambient temperatures may prevent the HO2S heater test from initiating.

The I/M System Status does not indicate whether the test has passed or failed, only that a decision was made. When all of the diagnostics for a specific system have run and passed, the I/M System Status will update to YES. If a test for a specific system has failed, the I/M System Status will update to YES, indicating a determination was made, even if all of the required tests have not run. When a failure occurs, the Emission Related DTC portion of the I/M System Status display will indicate the Malfunction Indicator Lamp (MIL) is requested. The I/M System Status also registers the number of Diagnostic Trouble Codes (DTCs).

The first failure of a type B DTC does not constitute a final determination of pass or fail, and will not update the I/M System Status to YES. A second trip is required, and all the conditions to run must be met in order for the test to run again. These conditions may include a partial to complete engine cool down.

The I/M System Status will update only when an emission related DTC fails the second time, or when all of the tests pass.

If there is an impending failure, the system may require more time to run the diagnostic than was allotted in the set procedure. If the test does not run after numerous attempts and no DTC is set, review the appropriate scan tool data list and the service information for an indication of why the test does not complete. Some tests may abort due to changes in the conditions while the test is running. For example, changes in engine load, such as a cooling fan or an A/C compressor clutch turning ON, may cause the test to abort.

If a diagnostic test is difficult to run, maintain necessary enable conditions until the system status updates to YES.

1. The Barometric Pressure (BARO) is more than 70 kPa.
2. The engine coolant has exceeded 140°F (60°C).
3. The Intake Air Temperature (IAT) is between 32-212°F (0-100°C).

The control module only runs the EGR Active Tests during a gradual deceleration with a closed throttle and a vehicle speed above 25 MPH (40 km/h). Several deceleration cycles may be necessary in order to accumulate a sufficient number of EGR flow samples. The procedure outlined in the table is for a clear, flat road. If the procedure is performed on a road with a slight down hill grade, the test may acquire the necessary sample counters in one or two decel trips. If the test is interrupted during the procedure, it may take more than three deceleration cycles to complete the test. If the status does not update, the test outlined in this procedure can be repeated until the I/M System Status updates to YES.

The I/M System Status does not indicate whether the test has passed or failed, only that a decision was made. When all of the diagnostics for a specific system have run and passed, the I/M System Status will update to YES. If a test for a specific system has failed, the I/M System Status will update to YES, indicating a determination was made, even if all of the required tests have not run. When a failure occurs, the Emission Related DTC portion of the I/M System Status display will indicate the Malfunction Indicator Lamp (MIL) is requested. The I/M System Status also registers the number of Diagnostic Trouble Codes (DTCs).

The first failure of a type "B" DTC does not constitute a final determination of pass or fail, and will not update the I/M System Status to YES. A second trip is required, and all the conditions to run must be met in order for the test to run again. These conditions may include a partial to complete engine cool down.

The I/M System Status will update only when an emission related DTC fails the second time, or when all of the tests pass.

If there is an impending failure, the system may require more time to run the diagnostic than was allotted in the set procedure. If the test does not run after numerous attempts and no DTC is set, review the appropriate scan tool data list and the service information for an indication of why the test does not complete. Some tests may abort due to changes in the conditions while the test is running. For example, changes in engine load, such as a cooling fan or an A/C compressor clutch turning ON, may cause the test to abort.

If a diagnostic test is difficult to run, maintain necessary enable conditions until the system status updates to YES.

1. Did you perform the Inspection/Maintenance (I/M) System Check? If YES, go to next step. If NO, see «INSPECTION/MAINTENANCE SYSTEM CHECK»(ref-158433-S34044282112003092600000) .
2. In order for this test to run, the vehicle must operate in the following conditions: Ensure the vehicle is within the Conditions for Running specified in the supporting text. Turn OFF all of the accessories, e.g., A/C, blower fan, etc. Start the engine and allow it to idle. Acceleration at part throttle to 80 km/h (50 mph) with this speed maintained for 1 minute. Four decelerations of 25 seconds each from 80 km/h (50 mph) while the following criteria is maintained: The throttle is closed. NO brake application on either manual or automatic transmission. NO clutch actuation on a manual transmission. NO manual downshift. The vehicle speed remains above 25 mph (40 km/h). After each deceleration period, the vehicle is returned to 50 mph (80 km/h) under part throttle acceleration and the speed is maintained for 15 seconds. With a scan tool, observe the I/M System Status display. Did the EGR System Status update to YES? If yes, go to step 5 . If no, go to next step.
3. With a scan tool, observe the DTC Information. Does the scan tool indicate any failed DTCs? If yes, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-158433-S36149293242003092600000) . If no, go to next step.
4. Refer to «INSPECTION/MAINTENANCE SYSTEM DTCS»(ref-158433-S41122999912003092600000) to determine which DTCs are required to run in order to complete this test. With a scan tool, observe the Not Ran Since Code Cleared display. Determine which of the DTCs required for a YES status has not run. Enter the DTC number in the Specific DTC menu of the scan tool. Operate the vehicle within the Conditions for Running the DTC, located in the supporting text for the diagnostic table of the DTC. Repeat the procedure until the scan tool indicates the diagnostic test has run. Repeat steps 4-6 for any additional required DTCs that have not run. With a scan tool, observe the I/M System Status display. Did the EGR System Status update to YES? If yes, go to next step. If no, see «DIAGNOSTIC AIDS»(ref-158433-S03426672182003111800000) .
5. With a scan tool, observe the Emission Related DTC portion of the I/M System Status display. Does the scan tool indicate any Emission Related DTCs set? If yes, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-158433-S36149293242003092600000) . If no, system okay.

DIAGNOSTIC TROUBLE CODE DEFINITIONS

DIAGNOSTIC TROUBLE CODE INDEX

Scheme 629

Scheme 630

Scheme 631

Scheme 632

Scheme 633

Scheme 634

Scheme 635

Scheme 636

Scheme 637

Scheme 638

Scheme 639

Scheme 640

Scheme 641

Scheme 642

Scheme 643

Scheme 644

Scheme 645

Scheme 646

Scheme 647

Scheme 648

Scheme 649

Scheme 650

Scheme 651

Scheme 652

Scheme 653

Scheme 654

Scheme 655

Scheme 656

Scheme 657

Scheme 658

Scheme 659

Scheme 660

Scheme 661

Scheme 662

Scheme 663

Scheme 664

Scheme 665

Scheme 666

Scheme 667

Scheme 668

Scheme 669

Scheme 670

Scheme 671

Scheme 672

Scheme 673

Scheme 674

Scheme 675

Scheme 676

Scheme 677

Scheme 678

Scheme 679

Scheme 680

Scheme 681

Scheme 682

Scheme 683

Scheme 684

Scheme 685

Scheme 686

Scheme 687

Scheme 688

DIAGNOSTIC TESTS

Note. Before clearing DTCs, perform powertrain diagnostic system check. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM. Record FREEZE FRAME and FAILURE RECORDS for reference during testing. Data will be erased when DTCs are cleared. If PCM is replaced, NEW PCM must be programmed using special manufacturer's equipment. See POWERTRAIN CONTROL MODULE under PROGRAMMING.

Conditions For Running DTC

1. Trucks Only DTCs P0401, P0404, or P0405 are not set.
2. DTCs P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0120, P0220, P0442, P0443, P0446, P0449, P0455, P0496, or P2135 are not set.
3. The engine is cranking or running.
4. The ignition 1 signal is between 11 volts and 18 volts.
5. The Throttle Position (TP) sensor angle is less than 95 percent.
6. The change in the TP sensor angle is less than 5 percent.
7. The MAP sensor is less than 80 kPa.
8. The change in the MAP sensor is less than 3 kPa.
9. The above conditions are met for 1.5 seconds.

Conditions For Setting DTC

The PCM detects that the actual MAF sensor frequency signal is not within a predetermined range of the calculated MAF value for more than 4 seconds.

Action Taken When DTC Sets

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions For Clearing MIL/DTC

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Inspect for the following conditions

1. An incorrectly routed harness. Inspect the harness of the MAF sensor in order to verify that it is not routed too close to the following components: The secondary ignition wires or coils. Any solenoids. Any relays. Any motors.
2. A low minimum air rate through the sensor bore may cause this DTC to set at idle or during deceleration. Inspect for any vacuum leaks downstream of the MAF sensor.
3. Inspect for any contamination or debris on the sensing elements of the MAF sensor.
4. Inspect the air induction system for any water intrusion. Any water that reaches the MAF sensor will skew the sensor and may cause this DTC to set.
5. A Wide Open Throttle (WOT) acceleration from a stop should cause the MAF sensor g/s display on the scan tool to increase rapidly. This increase should be from 7-12 g/s at idle to 230 g/s or more at the time of the 1-2 shift. If the increase is not observed, inspect for a restriction in the induction system or the exhaust system.
6. A high resistance of 15 ohms or more on the ignition 1 voltage circuit may cause this DTC to set. A high resistance may cause a driveability concern before this DTC sets.
7. The barometric pressure that is used in order to calculate the predicted mass air flow value is initially based on the MAP sensor at key ON. When the engine is running, the MAP sensor value is continually updated near wide open throttle. A skewed MAP sensor will cause the calculated mass air flow value to be inaccurate. The value shown for the MAP sensor display varies with the altitude. With the ignition ON and the engine OFF, 103 kPa is the approximate value near sea level. This value will decrease by approximately 3 kPa for every 1000 feet (305 meters) of altitude.
8. A high resistance on the 5-volt reference circuit of the MAP sensor may cause this DTC to set.
9. A high resistance on the low reference circuit of the MAP sensor may cause this DTC to set.
10. If the condition is intermittent, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

1. The engine is running for more than 2 seconds.
2. The engine speed is more than 400 RPM.
3. The ignition 1 signal is more than 8 volts.
4. The MAF sensor frequency is stable for more than one second.

The PCM detects that the MAF sensor frequency signal is less than 1300 Hz.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Inspect for the following conditions

1. Inspect the harness of the MAF sensor to verify that it is not routed too close to the following components: The secondary ignition wires or coils. Any solenoids. Any relays. Any motors. Any aftermarket accessories.
2. A low minimum air rate through the sensor bore at idle or during deceleration may cause this DTC to set. Inspect for any vacuum leak downstream of the MAF sensor.
3. Inspect for any contamination or debris on the sensing elements of the MAF sensor.
4. A wide open throttle acceleration from a stop should cause the MAF sensor g/s parameter on the scan tool to increase rapidly. This increase should be from 7-12 g/s at idle to 230 g/s or more at the time of the 1-2 shift. If the increase is not observed, inspect for a restriction in the induction system or the exhaust system.
5. Truck Only A high resistance of 15 ohms or more on the ground circuit of the MAF sensor may cause this DTC to set. A high resistance may cause a driveability concern before this DTC sets.
6. A high resistance of 15 ohms or more on the ignition 1 voltage circuit can cause this DTC to set. A high resistance may cause a driveability concern before this DTC sets.
7. If the condition is intermittent, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

1. The engine is running.
2. The engine speed is more than 400 RPM.
3. The ignition 1 signal is more than 8 volts.
4. The MAF sensor parameter is stable for more than 0.7 second.

The PCM detects that the MAF sensor frequency signal is more than 12,000 Hz.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. Inspect the air induction system for any water intrusion. The water rapidly cools the hot sensing elements in the sensor causing a false indication of excessive air flow. Any water that reaches the MAF sensor will skew the sensor and may cause this DTC to set.
2. A poor connection in the ignition 1 voltage circuit of the MAF sensor may cause this DTC to set.
3. If the condition is intermittent, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

1. DTC P0101, P0102, P0103, P0107, P0108, P0120, P0220, P0401, P0404, P0405, P0442, P0443, P0446, P0455, P1125, P1514, P1515, P1516, P1518, P2108, P2120, P2121, P2125, P2126, P2130, P2131, P2135 are not set.
2. The engine speed is between 400-5,000 RPM.
3. The change in engine speed is less than 125 RPM.
4. Traction control, if equipped, is not active.
5. The A/C compressor clutch is steady.
6. The power steering is stable.
7. The power take-off (PTO), if equipped, is not active.
8. The clutch switch state does not change, if equipped with a manual transmission.
9. The brake switch state does not change.
10. The above conditions are met for 1 second.

The PCM detects that the MAP sensor voltage is not within the predicted range for 1.5 seconds.

1. The Powertrain Control Module (PCM) illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The PCM turns OFF the Malfunction Indicator Light (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. DTC P0120, P0220, P1125, P1514, P1515, P1516, P1518, P2108, P2120, P2121, P2125, P2126, P2130, P2131, P2135 are not set.
2. The engine is running.
3. The throttle angle is zero percent when the engine speed is less than 800 RPM, or the throttle angle is more than 12.5 percent when the engine speed is more than 800 RPM.

The PCM detects that the MAP sensor voltage is less than 0.10 volt for more than 2 seconds.

1. The Powertrain Control Module (PCM) illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The Powertrain Control Module (PCM) turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. DTC P0120, P0220, P1125, P1514, P1515, P1516, P1518, P2108, P2120, P2121, P2125, P2126, P2130, P2131, P2135 are not set.
2. Engine is running for a length of time that is determined by the start-up coolant temperature. The length of time ranges from 4 minutes at less than -22° F (-30° C) to 30 seconds at more than 86° F (30° C).
3. The throttle angle is less than one percent when the engine speed is less than 1,200 RPM, or the throttle angle is less than 20 percent when the engine speed is more than 1,200 RPM.

The PCM detects that the MAP sensor voltage is more than 4.9 volts for more than 2 seconds.

1. The Powertrain Control Module (PCM) illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The Powertrain Control Module (PCM) records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The Powertrain Control Module (PCM) turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. DTCs P0502, P0503 are not set.
2. The engine run time is more than 45 seconds.
3. The Vehicle Speed Sensor (VSS) indicates that vehicle speed is more than 25 MPH.

The IAT is more than 262°F (128°C) for 5 seconds.

1. The Powertrain Control Module (PCM) illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The PCM turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. When the vehicle is at ambient temperature the IAT sensor and ECT sensor temperatures should be relatively close to each other.
2. If an intermittent condition exists, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

Scheme 689

Scheme 690

1. DTCs P0101, P0102, P0103, P0116, P0117, P0118, P0125, P0128, P0502, P0503 are not set.
2. The engine run time is more than 120 seconds.
3. The Vehicle Speed Sensor (VSS) indicates that vehicle speed is less than 7 MPH.
4. The Engine Coolant Temperature (ECT) is more than 140°F (60°C).
5. The Mass Air Flow (MAF) is less than 15 g/s.

The PCM detects that the IAT Sensor parameter is less than -38°C (-36°F) for more than 5 seconds.

1. The Powertrain Control Module (PCM) illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The PCM turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. When the vehicle is at ambient temperature the IAT sensor and ECT sensor temperatures should be relatively close to each other.
2. If a short to a separate 5-volt source occurs, this DTC may set. If this condition exists, a continuity test to all other PCM 5-volt reference circuits will be necessary.
3. If an intermittent condition exists, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

1. The ignition is ON.
2. DTCs P0112, P0113, P0117, P0118, P0125, P0128, P0601, P0602, P1621, P1683 are not set.
3. The vehicle has a minimum ignition OFF time of 10 hours.

If the PCM detects a temperature difference between the ECT sensor and the IAT sensor of more than 27°F (15°C), then the vehicle must be driven for more than 400 seconds over 15 mph. If the IAT sensor temperature decreases more than 5°F (3°C), a block heater is detected and the test is aborted. If the IAT sensor temperature does not decrease, a block heater was not detected and DTC P0116 sets.

1. The Powertrain Control Module (PCM) illuminates the Malfunction Indicator Light (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The Powertrain Control Module turns OFF the Malfunction Indicator Light (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. DTC P0116 is designed to detect a ECT sensor that is skewed high.
2. An IAT sensor that is skewed low could cause this DTC to set.
3. When testing the ECT sensor or the IAT sensor, the Temperature Vs Resistance table should be used to determine if a skewed sensor is the problem. See «TEMPERATURE VS. RESISTANCE»(ref-158433-S12013627562003092600000) .

1. DTCs P0101, P0102, P0103, P0116, P0117, P0118, P0125, P0128, P0502, P0503 are not set.
2. The engine run time is more than 120 seconds.
3. The Vehicle Speed Sensor (VSS) indicates that the vehicle speed is less than 7 MPH.
4. The Engine Coolant Temperature (ECT) is more than 140° F (60° C).
5. The Mass Air Flow (MAF) is less than 15 g/s.

The PCM detects that the IAT sensor parameter is less than -36° F (-38° C) for more than 5 seconds.

1. The Powertrain Control Module (PCM) illuminates the Malfunction Indicator Light (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The Powertrain Control Module turns OFF the Malfunction Indicator Light (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. DTC P0116 is designed to detect a ECT sensor that is skewed high.
2. An IAT sensor that skewed low could cause this DTC to set.
3. When testing the ECT sensor or the IAT sensor, the Temperature Vs Resistance table should be used to determine if a skewed sensor is the problem. See «TEMPERATURE VS. RESISTANCE»(ref-158433-S12013627562003092600000) .

The engine run time is more than 10 seconds; or, the engine run time is less than 10 seconds when IAT is less than 122°F (50°C).

The ECT sensor temperature is more than 282°F (139°C) for more than 20 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions For Clearing MIL or DTC

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. An overheating condition may cause this DTC to set.
2. After starting the engine, the ECT sensor temperature should rise steadily to about 194°F (90°C) then stabilize after the thermostat opens.
3. Use the Temperature vs. Resistance Value Table in order to test the ECT sensor at various temperature levels in order to evaluate the possibility of a skewed sensor. A skewed sensor could result in poor driveability concerns. See «TEMPERATURE VS. RESISTANCE»(ref-158433-S12013627562003092600000) .
4. If an intermittent condition exists, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

Scheme 691

The engine has been running for more than 60 seconds; or, the engine run time is less than 60 seconds when the Intake Air Temperature (IAT) is more than 32°F (0°C).

The ECT sensor temperature is less than -36°F (-38°C) for 20 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. If a short to a separate 5-volt source occurs, this DTC may set.
2. After starting the engine, the ECT should rise steadily then stabilize after the thermostat opens.
3. Use the Temperature vs. Resistance Table in order to test the ECT sensor at various temperature levels in order to evaluate the possibility of a skewed sensor. A skewed sensor could result in poor driveability concerns. See «TEMPERATURE VS. RESISTANCE»(ref-158433-S12013627562003092600000) .
4. If an intermittent condition exists, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

Scheme 692

Scheme 693

1. DTCs P1518 or P2108 are not set.
2. The ignition switch is in the crank or run position.
3. The ignition voltage is more than 5.23 volts.

1. The TP sensor 1 signal voltage is less than 0.37 volt or more than 4.51 volts.
2. The above condition is present for more than 1 second.

1. The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.
3. The control module commands the TAC system to operate in the Reduced Engine Power Mode.
4. Under certain conditions the control module commands the engine OFF.
5. The message center displays Reduced Engine Power.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. Inspect the Throttle Actuator Control (TAC) module connectors for signs of water intrusion. When this occurs, multiple DTCs could be set with no circuit or component conditions found during diagnostic testing.
2. When the TAC module detects a condition within the TAC system, more than one TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Disconnecting components during testing may set additional DTCs. Keep this in mind when reviewing the stored information, Capture info.
3. If this DTC is determined to be intermittent, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

1. DTCs P0101, P0102, P0103, P0112, P0113, P0116, P0117, P0118, P0500, P0502, P0503, P1111, P1112, P1114, or P1115 are not present.
2. The engine run time is between 120-1400 seconds.
3. The minimum air temperature is 19° F (-7° C).
4. The start-up coolant temperature is less than 104°F (40°C).
5. The Mass Air Flow (MAF) average is more than 20 g/s.
6. The vehicle speed is more than 5 MPH for more than 0.5 mi.
7. This diagnostic has not previously run this ignition cycle.

1. The PCM detects that the calibrated amount of engine run time has been met.
2. The calibrated amount of engine air flow has been met.
3. The engine coolant temperature for Closed Loop of 113° F (45° C) has not been met.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC P0125 is designed to detect a skewed ECT sensor or a faulty thermostat.

Excessive coolant flow through the by-pass hose to the throttle body may cause this DTC to set.

1. DTCs P0101, P0102, P0103, P0112, P0113, P0116, P0117, P0118, P0500, P0502, P0503 are not present.
2. The engine run time is between 120-1400 seconds.
3. The minimum air temperature is more than 19° F (-7° C).
4. The start-up coolant temperature is less than 104° F (40° C).
5. The Mass Air Flow (MAF) average is more than 20 g/s.
6. The vehicle speed is more than 5 MPH for more than 0.5 miles.
7. The diagnostic has not previously run this ignition cycle.

The PCM detects all of the following conditions

1. The calibrated amount of engine run time has been met.
2. The calibrated amount of engine air flow has been met.
3. The calibrate vehicle speed and distance have been met.
4. The engine coolant temperature for Closed Loop of 113° F (45° C) has not been met.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Scheme 694

Scheme 695

1. DTCs P0101, P0102, P0103, P0112, P0113, P0116, P0117, P0118, P0125, P0500, P0502, P0503, P1111, P1112, P1114, or P1115 are not present.
2. The start-up engine coolant temperature is less than 165°F (74°C).
3. The Air Intake Temperature (IAT) sensor is 19°F (-7°C) or more.
4. The engine is running more than 2 minutes and less than 27 minutes.
5. The vehicle speed is more than 5 MPH for more than 1.5 miles.
6. The mass airflow (MAF) average reading is more than 20 g/s.
7. The diagnostic has not previously run this ignition cycle.

1. The calibrated amount of engine run time has been met.
2. The calibrated amount of engine air flow has been met.
3. The calibrated minimum engine coolant temperature of 174° F (79° C) has not been met.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. A DTC P0128 is designed to detect a faulty thermostat.
2. Excessive coolant flow through the by-pass hose to the throttle body may cause this DTC to set.
3. A skewed ECT sensor may cause a P0128 to set.

1. DTCs P0101, P0102, P0103, P0112, P0113, P0116, P0117, P0118, P0125, P0500, P0502, P0503 are not present.
2. The start-up engine coolant temperature is less than 165°F (74°C).
3. The Air Intake Temperature (IAT) sensor is 19°F (-7°C) or more.
4. The engine is running more than 2 minutes and less than 27 minutes.
5. The vehicle speed is more than 5 MPH for more than 1.5 miles.
6. The mass airflow (MAF) average reading is more than 20 g/s.
7. The diagnostic has not previously run this ignition cycle.

The PCM detects all of the following conditions

1. The calibrated amount of engine run time has been met.
2. The calibrated amount of engine air flow has been met.
3. The calibrated vehicle speed and distance have been met.
4. The calibrated minimum engine coolant temperature of 174°F (79°C) has not been met.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Scheme 696

Scheme 697

Lean Test Enable

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0200, P0220, P0300, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1404, P1514, P1515, P1516, P1518, P2108 or P2135 are not set.
2. The loop status is closed.
3. The ignition 1 signal is between 10-18 volts.
4. The fuel tank level remaining is more than 10 percent.
5. The TP indicated angle parameter is between 3-70 percent more than the value observed at idle.

Power Enrichment Test Enable

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0200, P0220, P0300, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1514, P1515, P1516, P1518, P2108 or P2135 are not set.
2. The loop status is closed.
3. The ignition 1 signal is between 10-18 volts.
4. The fuel tank level remaining is more than 10 percent.
5. The engine run time parameter is more than 30 seconds.
6. The power enrichment parameter is active for more than 2 seconds.

Lean Test

1. The HO2S voltage is less than 200 mV for 165 seconds.

Power Enrichment Test

1. The HO2S voltage is less than 400 mV for 10 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
3. The control module commands Open Loop.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Rich Test Enable

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0200, P0220, P0300, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1404, P1514, P1515, P1516, P1518, P2108, or P2135 are not set.
2. The loop status is closed.
3. The ignition 1 signal is between 10-18 volts.
4. The fuel tank level remaining is more than 10 percent.
5. The TP indicated angle parameter is between 3-70 percent more than the value observed.

Decel Fuel Cut-Off Test Enable

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0200, P0220, P0300, P0401, P0404, P0P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1514, P1515, P1516, P1518, P2108, or P2135 are not set.
2. The loop status is closed.
3. The ignition 1 signal is between 10-18 volts.
4. The fuel tank level remaining is more than 10 percent.
5. The engine run time parameter is more than 30 seconds.
6. The Decel. Fuel Cutoff parameter is active for more than 4 seconds.

Rich Test

1. The HO2S voltage is more than 900 mV for 165 seconds.

Decel Fuel Cut-Off Test

1. The HO2S voltage is more than 250 mV for 5 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
3. The control module commands Open Loop.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0116, P0118, P0120, P0131, P0132, P0134, P0135, P0151, P0152, P0154, P0155, P0200, P0220, P0300, P0401, P0404, P0405, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1404, P1514, P1515, P1516, P1518, P2108 or P2135 are not set.
2. The Engine Coolant Temperature (ECT) sensor is more than 140°F (60°C).
3. The Evaporative (EVAP) emissions purge solenoid command is more than 1 percent.
4. The mass airflow (MAF) sensor is between 29-55 g/s.
5. The engine speed is between 1000-3000 RPM.
6. The TP Indicated Angle parameter is 5 percent more than the value observed at idle.
7. The loop status is closed.
8. The ignition 1 signal is between 10-18 volts.
9. The fuel tank level remaining is more than 10 percent.
10. The engine run time is more than 160 seconds.
11. The above conditions are met for 100 seconds.

The rich-to- lean or lean-to-rich average response time is more than a calibrated value.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0200, P0220, P0300, P0401, P0404, P0405, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1404, P1514, P1515, P1516, P1518, P2108 or P2135 are not set.
2. The engine run time is more than 300 seconds.
3. The ignition 1 signal is between 10-18 volts.

The PCM detects that the affected HO2S voltage parameter is between 350-550 mV for 60 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
3. The control module commands Open Loop.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0200, P0220, P0300, P0401, P0404, P0405, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1404, P1514, P1515, P1516, P1518, P2108 or P2135 are not set.
2. The ECT Sensor parameter is more than 122°F (50° C).
3. The Ignition 1 Signal parameter is between 10-18 volts.
4. The MAF sensor parameter is between 3-40 g/s.
5. The engine speed parameter is between 500-3000 RPM.
6. The engine run time parameter is more than 120 seconds.

1. The PCM detects that the affected HO2S Heater current parameter is more than 3.125 amps or less than 0.25 amps.
2. The above condition is met for 10 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Lean Test Enable

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0200, P0220, P0300, P0401, P0404, P0405, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1404, P1514, P1515, P1516, P1518, P2108, P2135 are not set.
2. The loop status is closed.
3. The ignition 1 signal is between 10-18 volts.
4. The fuel tank level remaining is more than 10 percent.
5. The TP indicated angle parameter is between 3-70 percent more than the value observed at idle.

Power Enrichment Test Enable

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0200, P0220, P0300, P0401, P0404, P0405, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1404, P1514, P1515, P1516, P1518, P2108, P2135 are not set.
2. The loop status is closed.
3. The ignition 1 signal is between 10-18 volts.
4. The fuel tank level remaining is more than 10 percent.
5. The engine run time parameter is more than 30 seconds.
6. The power enrichment parameter is active for more than 2 seconds.

Lean Test

1. The HO2S voltage is less than 80 mV for 200 seconds.

Power Enrichment Test

1. The HO2S voltage is less than 490 mV for 10 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Rich Test Enable

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0200, P0220, P0300, P0401, P0404, P0405, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1404, P1514, P1515, P1516, P1518, P2108, or P2135 are not set.
2. The loop status is closed.
3. The ignition 1 signal is between 10-18 volts.
4. The fuel tank level remaining is more than 10 percent.
5. The TP indicated angle parameter is between 3-70 percent more than the value observed at idle.

Decel Fuel Cut-Off Test Enable

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0200, P0220, P0300, P0401, P0404, P0405, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1404, P1514, P1515, P1516, P1518, P2108, or P2135 are not set.
2. The loop status is closed.
3. The ignition 1 signal is between 10-18 volts.
4. The fuel tank level remaining is more than 10 percent.
5. The engine run time parameter is more than 30 seconds.
6. The Decel. Fuel Cutoff parameter is active for more than 4 seconds.

Rich Test

1. The PCM detects that the affected HO2S voltage parameter is more than 950 mV for 200 seconds.

Decel Fuel Cut-Off Test

1. The PCM detects that the affected HO2S voltage parameter is more than 250 mV for 5 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0141, P0161, P0200, P0220, P0300, P0401, P0404, P0405, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1404, P1514, P1515, P1516, P1518, P2108 or P2135 are not set.
2. The engine run time is more than 300 seconds.
3. The loop status is closed.
4. The ignition 1 signal is between 10-18 volts.

1. The HO2S signal voltage is steady between 410-490 mV for 150 seconds.
2. The Throttle Position (TP) changes more than 5 percent within 1 second, 6 times.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. DTCs P0101, P0103, P0108, P0135, P0137, P0141, P0300, P0420, P0430, P0442, P0443, P0446, P0449, P0506, or P0507 are not set.
2. The Engine Coolant Temperature (ECT) is between 167-239°F (75-115°C).
3. The Intake Air Temperature (IAT) is between 4-194° F (-20-90° C).
4. The Manifold Absolute Pressure (MAP) is between 3.7-13 psi (26-90 kPa).
5. The vehicle speed is less than 85 mph (137 km/h).
6. The engine speed is between 400-3000 RPM.
7. The Barometric pressure (BARO) is more than 10.7 psi (74 kPa).
8. The Mass Airflow (MAF) is between 5-90 g/s.
9. The fuel level is more than 10 percent.
10. The Throttle Position (TP) is less than 90 percent.

1. The average long term fuel trim cell value is above 23 percent.
2. All of the above conditions are present for 6 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. The system will go lean if an injector is not supplying enough fuel.
2. A lean condition could be present during high fuel demand.
3. Using a scan tool, review the Failure Records. If an intermittent condition is suspected, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

1. DTCs P0101, P0103, P0108, P0135, P0137, P0141, P0200, P0300, P0420, P0430, P0442, P0443, P0446, P0449, P0506, or P0507 are not set.
2. The Engine Coolant Temperature (ECT) is between 167-239°F (75-115°C).
3. The Intake Air Temperature (IAT) is between 4-194°F (-20 to 90°C).
4. The Manifold Absolute Pressure (MAP) is between 26-90 kPa.
5. The vehicle speed is less than 85 MPH.
6. The engine speed is between 400-3000 RPM.
7. The Barometric (BARO) pressure is more than 74 kPa.
8. The Mass Airflow (MAF) is between 5-90 g/s.
9. The fuel level is more than 10 percent.
10. The Throttle Position (TP) is less than 90 percent.

1. The average long term fuel trim value is below -13 percent.
2. All of the above conditions are present for 40 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. Fuel contamination, such as water or alcohol, will effect fuel trim.
2. A malfunctioning MAF sensor can cause a rich condition and set this DTC. See «DTC P0101: MASS AIR FLOW SENSOR PERFORMANCE»(ref-158433-S24833937592003092600000) .
3. Using a scan tool, review the Failure Records. If an intermittent condition is suspected, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

1. The engine speed is more than 400 RPM.
2. The ignition voltage is between 6-18 volts.

1. The PCM detects an incorrect voltage on the fuel injector control circuit.
2. The condition exists for 5 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. Performing the Fuel Injector Coil test may help isolate an intermittent condition. See «FUEL INJECTOR COIL TEST»(ref-153339-S13092179522003040200000) under FUEL SYSTEMS in SYSTEM & COMPONENT TESTING - 8.1L AVALANCHE, SIERRA, SILVERADO, SUBURBAN & YUKON XL article.
2. For an intermittent condition, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

1. DTCs P1518 or P2108 are not set.
2. The ignition switch is in the crank or run position.
3. The ignition voltage is more than 5.23 volts.

1. The TP sensor 2 voltage is less than 0.28 volt or greater than 4.60 volts.
2. The above condition is present for more than 1 second.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.
3. The control module commands the TAC system to operate in the Reduced Engine Power mode.
4. Under certain conditions the control module commands the engine OFF.
5. The message center displays Reduced Engine Power.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL/DTC with a scan tool.

1. Inspect the Throttle Actuator Control (TAC) module connectors for signs or water intrusion. If water intrusion occurs, multiple DTCs may set without any circuit or component found during diagnostic testing.
2. When the TAC module detects a condition within the TAC system, more than 1 TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing 1 individual condition may correct more than 1 DTC. Disconnecting components during testing may set additional DTC. Remember this if you review the stored information in Capture Info.
3. For an intermittent condition, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

1. The engine speed is more than 400 RPM.
2. The ignition voltage is between 6-18 volts.

1. The PCM detects that the commanded state of the driver and the actual state of the control circuit do not match.
2. The above conditions are present for a minimum of 2.5 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Use a scan tool in order to clear the MIL and the DTC.

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0125, P0128, P0220, P0315, P0335, P0336, P0341, P0343, P0721, P0722, P1114, P1115, P1120, or P1258 are not set.
2. The engine speed is between 450-5000 RPM.
3. The ignition voltage is between 10-18 volts.
4. The Engine Coolant Temperature (ECT) is between 19-266°F (-7 to 130°C).
5. The fuel level is more than 10 percent.
6. The Throttle Position (TP) sensor angle is steady within 1 percent.
7. The anti-lock brake system (ABS) and the traction control system are not active.
8. The transmission is not changing gears.
9. The A/C clutch is not changing states.
10. The PCM is not in fuel shut-off or Decel Fuel Cut-Off (DFCO) mode.
11. The PCM is not receiving a rough road signal.

The PCM is detecting a crankshaft rotation speed variation indicating a misfire sufficient to cause emission levels to exceed mandated standards.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. Excessive vibration from sources other than the engine can cause a misfire DTC. The following are possible sources of vibration: Variable thickness brake rotor. Drive shaft not balanced. Worn or damaged accessory drive belt.
2. There may be more or less cylinders actually misfiring than indicated by the scan tool.
3. Spray water on the secondary ignition components using a spray bottle. Look and listen for arcing or misfiring.
4. If there are multiple misfires on only one bank, inspect the fuel injector and ignition coil, power and ground circuits for that bank.

DTCs P0335, P0336, P0341, P0342, or P0343 are not set.

The Engine Coolant Temperature (ECT) is more than 158° F (70° C).

The CKP system variation values are not stored in the PCM memory.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
2. the control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The CKP system variation compensating values are stored in PCM memory after a learn procedure has been performed. If the actual CKP variation is not within the CKP system variation compensating values stored in the PCM, DTC P0300 may set.

The CKP system variation learn procedure is also required when the following service procedures have been performed, regardless of whether DTC P0315 is set.

1. An engine replacement.
2. A PCM replacement.
3. A harmonic balancer replacement.
4. A crankshaft replacement.
5. Any engine repairs which disturb the CKP sensor relationship.

If the CKP system variation learn procedure cannot be performed successfully, check for the following conditions and correct as necessary

1. A damaged reluctor wheel.
2. Excessive crankshaft runout.
3. A damaged crankshaft.
4. Interference in the signal circuit of the CKP sensor.
5. A coolant temperature that is not within the Conditions For Running DTC.
6. The ignition switch is in the ON position until the battery is drained.

A PCM power disconnect with the ignition ON may erase the stored value and set the DTC P0315.

Scheme 698

1. The engine is running.
2. The engine run time is more than 10 seconds.
3. The ignition voltage is more than 10 volts.

A malfunction with the KS system or the circuits within the PCM are faulty for 15 seconds or more.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Scheme 699

1. DTCs P0106, P0107, P0108, P0116, P0117, P0118, P0125, P1114 or P1115 are not set.
2. The engine speed is between 1600-3000 RPM.
3. The Manifold Absolute Pressure (MAP) is less than 49 kPa.
4. The Engine Coolant Temperature (ECT) is more than 140°F (60°C).
5. The engine run time is more than 20 seconds.
6. The ignition voltage is more than 10 volts.

The PCM determines that this frequency is less than or more than the expected amount for 3 seconds or more.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Inspect the KS for proper installation. A KS that is loose or over torqued may cause either DTC to set.

1. DTCs P0101, P0102, P0103, P0341, P0342, or P0343 are not set.
2. The camshaft position (CMP) sensor signal is transitioning.
3. The Mass Air Flow (MAF) is more than 3 g/s in the crank mode.
4. The MAF is more than 5 g/s in the running mode.

The PCM determines there is no signal from the CKP sensor for more than 3 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The following conditions may cause this DTC to set

1. Excessive air gap between the CKP sensor and the reluctor wheel.
2. Crankshaft reluctor wheel damage or improper installation.
3. Foreign material passing between the CKP sensor and the reluctor wheel.
4. Insufficient fuel.

Excess crankshaft end play causes the CKP sensor reluctor wheel to move out of alignment with the CKP sensor. This could result in any one of the following

1. A no-start.
2. A start and stall.
3. Erratic performance.

For an intermittent, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.

The engine is cranking or running.

The PCM determines that the CKP sensor signal is out of range for more than 120 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The following problems may cause this DTC to set

1. Poor connections.
2. Crankshaft reluctor wheel damage or improper installation.
3. Excessive air gap between the sensor and the reluctor wheel.
4. The engine running out of fuel.
5. The crankshaft rotates backwards, this DTC sets. This condition is only with vehicles equipped with a manual transmission. This condition occurs when a vehicle is on an incline and the clutch is released and an engine stall occurs.

Excess crankshaft end play will cause the CKP sensor reluctor wheel to move out of alignment with the CKP sensor. This could result in any one of the following conditions

1. A no-start.
2. A start and stall.
3. Erratic performance.

For an intermittent, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.

The engine speed is less than 4,000 RPM.

The PCM detects that a CMP to CKP mis-match has occurred.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The following conditions may cause this DTC to set

1. Camshaft reluctor wheel damage.
2. Sensor contact with the reluctor wheel.
3. Foreign material passing between the sensor and the reluctor wheel.
4. Excessive camshaft end-play.
5. Wiring routed too close to secondary ignition components.

If the condition is intermittent, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.

The engine is running and the engine speed is less than 4000 RPM.

The PCM detects the cam signal is stuck low for 1.5 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The following conditions may cause this DTC to set

1. Camshaft reluctor ring damage.
2. The sensor coming in contact with the reluctor ring.
3. Foreign material passing between the sensor and the reluctor ring.
4. Excessive camshaft end-play.
5. Wiring routed too close to secondary ignition components.

If the condition is intermittent, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.

The engine speed is less than 4000 RPM.

The PCM detects the CAM signal is high for 1.5 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The following conditions may cause this DTC to set

1. Camshaft reluctor ring damage.
2. The sensor coming in contact with the reluctor ring.
3. Foreign material passing between the sensor and the reluctor ring.
4. Excessive camshaft end-play.
5. Wiring routed too close to secondary ignition components.

If the condition is intermittent, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.

The engine is operating.

The PCM detects the IC circuit is grounded, open, or shorted to voltage for less than 1 second.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0120, P0200, P0220, P0300, P0335, P0336, P0404, P0500, P0502, P0503, P0506, P0507, P0562, P0563, P1125, P1404, P2135 are not set.
2. The ignition 1 signal parameter is between 11-18 volts.
3. The Throttle Position (TP) sensor parameter is less than 1.2 percent.
4. The Intake Air Temperature (IAT) sensor parameter is between 32-212° F (0-100° C).
5. The Engine Coolant Temperature (ECT) sensor parameter is more than 140° F (60° C).
6. The engine speed parameter is between 725-1700 RPM.
7. The Manifold Absolute Pressure (MAP) sensor parameter is between 18-42 kPa.
8. The Mass Air Flow (MAF) sensor parameter does not change more than 3 grams per second.
9. The vehicle speed sensor parameter is more than 25 MPH during deceleration.
10. The Barometric Pressure (BARO) is more than 75 kPa.
11. The vehicle will need to be driven at more than 50 MPH, and then allowed to decelerate. When the vehicle is decelerating, while meeting all of the criteria listed above, the PCM will enable the EGR flow test to run. As the EGR flow test is running, you will see the Desired EGR position parameter and the EGR position sensor parameter on the scan tool momentarily change from 0 to a calibrated value above 0.

The MAP changes monitored by the PCM during the EGR flow test indicate an insufficient amount of EGR flow.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Inspect for the following conditions

1. A vacuum restriction to the MAP sensor. A skewed MAP sensor reading can cause the PCM to read incorrect MAP changes during the EGR flow test.
2. An engine that is running poorly due to a mechanical condition. These types of conditions can cause low engine vacuum and thus cause a higher than expected MAP sensor reading.
3. Excessive back pressure in the exhaust system may cause this DTC to set. This condition can cause low engine vacuum and thus cause a higher than expected MAP sensor reading, Possible causes of this could be a restriction in the exhaust system or non Original Equipment Manufacture (OEM) exhaust parts.
4. Exhaust system leaks can cause an insufficient amount of EGR flow through the EGR valve. This condition can cause less than expected changes due to insufficient exhaust back pressure. Possible causes of this could be a leaking exhaust system, a leaking EGR pipe or non Original Equipment Manufacture (OEM) exhaust parts.

1. The ignition 1 signal parameter is between 11-18 volts.
2. The EGR valve is commanded open.

1. The difference between the desired EGR position parameter and the EGR position sensor parameter is more than 12 percent.
2. The condition is present for more than 10 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. Inspect for excessive deposits on the EGR pintle or seat. Remove EGR valve.
2. Inspect for deposits that may interfere with the EGR valve pintle extending completely or may cause the pintle to stick.
3. If the condition is intermittent, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

Scheme 700

Scheme 701

Scheme 702

The Ignition 1 Signal parameter is between 11-18 volts.

1. The EGR Position Sensor parameter is less than 0.16 volts.
2. The above condition is met for more than 5 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunctions Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL/DTC with a scan tool.

Scheme 703

Scheme 704

1. DTCs P0101-P0103, P0106-P0108, P0112, P0113, P0117, P0118, P0120, P0125, P0128, P0131-P0135, P0137, P0138, P0140, P0141, P0151-P0155, P0157, P0158, P0160, P0161, P0171, P0172, P0174, P0175, P0200, P0220, P0300, P0325, P0327, P0332, P0335, P0336, P0341-P0343, P0351-P0358, P0442, P0443, P0446, P0452, P0453, P455, P0496, P0502, P0503, P1125, P1133, P1153, P1514, P1516, P1518, P2108 or P2135 are not set.
2. The Intake Air Temperature (IAT) is 19-185°F (-7-85°C).
3. The Barometric (BARO) pressure is more than 74 kPa.
4. The vehicle has been driven at more than 900 RPM for 50 seconds.
5. The Engine Coolant Temperature (ECT) is 158-248°F (70-120°C).
6. The engine must be at idle for one of the following amounts of time: 45 seconds in neutral for manual transmissions. 40 seconds in gear for automatic transmissions.
7. The Closed Loop fuel control is enabled.

The PCM determines the oxygen storage capability of the catalytic converter has degraded below a calibrated threshold.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) the first time the diagnostic runs and fails.
2. The control module will set the DTC and records the operating conditions at the time the diagnostic fails. The control module stores the failure information in the scan tools Freeze Frame/Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. The catalyst test may abort due to a change in the engine load. DO NOT change the engine load during the test. During the test, DO NOT reset the AC, Coolant Fan, or the Heater Motor.
2. Inspect the fuel control oxygen sensor wiring harness for a short to the catalysts monitor wiring harness.
3. Driving the vehicle under the conditions outlined in «DRIVE CYCLES»(ref-158433-S03879271962003092600000) can verify whether the fault is present.
4. Certain conditions may cause a catalytic converter to degrade. These conditions may include the following: An engine misfire, which can cause catalytic convertor overheating. High engine oil high coolant consumption. Retarded spark timing. A conditions that may cause low secondary ignition voltage, which can cause incomplete combustion. A lean fuel mixture. A rich fuel mixture. A shorted oxygen sensor wiring harness.
5. Correct any condition that may cause an engine performance concern.
6. If an intermittent condition cannot be duplicated, the information included in the Freeze Frame/Failure Records can be useful in determining the vehicle operating conditions when the DTC was set.

1. DTCs P0100, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0125, P0335, P0336, P0443, P0446, P0449, P0452, P0453, P0455, P0496, P0500, P0502, P0721, P0722, P1106, P1107, or P1683 are not set.
2. The diagnostic runs once with a 10 hour minimum between tests after a fail.
3. DTC P0455 must run and pass.
4. The start up intake air temperature (IAT) is between 39-86° F (4-30° C).
5. The start up Engine Coolant Temperature (ECT) is less than 86° F (30° C).
6. The start up IAT and ECT are within 15° F (8° C).
7. The Barometric Pressure (BARO) is more than 74 kPa.
8. The ambient air temperature is between 36-90° F (2-32° C).
9. The engine run time minimum is 600 seconds.
10. The odometer displays more than 10 miles.
11. The vehicle has traveled more than 3 miles this trip.
12. The ECT is more than 158° F (70° C).
13. The fuel level is between 15-85 percent.
14. The ignition is OFF.

The control module detects a pressure change that is less than a calibrated amount.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

1. The PCM will turn the MIL OFF during the first consecutive trip in which the diagnostic has been run and passed.
2. A last test failed (current DTC) clears when the PCM turns OFF the MIL.
3. The history DTC will clear after the PCM runs and passes 40 consecutive warm up cycles with no failure.
4. The DTC can be cleared by using a scan tool.

1. To help locate intermittent leaks, use the J 41413-200 Evaporative Emissions System Tester (EEST) to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with the J 41413-SPT High Intensity White Light.
2. To improve visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT.
3. If the condition is intermittent, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

1. The engine speed is more than 400 RPM.
2. The system voltage is between 6-18 volts.

1. The control module detects that the commanded state of the driver and the actual state of the control circuit do not match.
2. The above conditions are present for a minimum of 5 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. DTCs P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0125, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0151, P0152, P0153, P0154, P0155, P0157, P0158, P0160, P0161, P0220, P0442, P0443, P0449, P0452, P0453, P0455, P0500, P1111, P1112, P1114, or P1115 are not set.
2. The ignition voltage is between 10-18 volts.
3. The Barometric (BARO) pressure is more than 75 kPa.
4. The fuel level is between 15-85 percent.
5. The Engine Coolant Temperature (ECT) is between 39-86°F (4-30°C).
6. The Intake Air Temperature (IAT) is between 39-86°F (4-30°C).
7. The start up ECT and IAT are within 16°F (9°C) of each other.

1. The Fuel Tank Pressure (FTP) is less than -10 in. H2O.
2. The condition is present for more than 30 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

An intermittent Condition could be caused by a damaged EVAP vent housing, a temporary blockage at the EVAP vent valve inlet, or a pinched vent hose. A blockage in the vent system will also cause a poor fuel fill problem. If the condition is intermittent, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.

1. The engine speed is more than 400 RPM.
2. The system voltage is between 6-18 volts.

1. The control module detects that the commanded state of the driver and the actual state of the control circuit do not match.
2. The above conditions are present for a minimum of 5 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The engine is running.

1. The fuel tank pressure sensor voltage is less than 0.1 volt.
2. All conditions are present for greater than 5 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The engine is running.

1. The fuel tank pressure sensor voltage is more than 4.9 volts.
2. All conditions are present for greater than 5 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. DTC P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0125, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0151, P0152, P0153, P0154, P0155, P0157, P0158, P0160, P0161, P0220, P0442, P0443, P0446, P0449, P0452, P0453, P0500, P1111, P1112, P1114, or P1115 are not set.
2. The engine is running.
3. The ignition voltage is between 10-18 volts.
4. The Barometric Pressure (BARO) is more than 75 kPa.
5. The fuel level is between 15-85 percent.
6. The Engine Coolant Temperature (ECT) is between 39-149° F (4-65° C).
7. The Intake Air Temperature (IAT) is between 39-167° F (4-75° C).
8. The start-up ECT and IAT are within 16° F (9° C) of each other.

The EVAP system is not able to achieve or maintain vacuum during the diagnostic test.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The fires time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. To help locate intermittent leaks, use the J 41413-200 Evaporative Emissions System Tester (EEST) to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with the J 41413-SPT High Intensity White Light. Introducing smoke in 15 second intervals will allow less pressure into the EVAP system. When the system is less pressurized, the smoke will sometimes escape in a more condensed manner.
2. A temporary blockage in the EVAP purge solenoid purge pipe or EVAP canister could cause an intermittent condition. Inspect and repair intermittent condition. Inspect and repair any restriction in the EVAP system.
3. To improve visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT.
4. Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.
5. If the condition is intermittent, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

1. DTC P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0125, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0147, P0151, P0152, P0153, P0154, P0155, P0157, P0158, P0160, P0161, P0220, P0442, P0443, P0446, P0449, P0452, P0453, P0455, P0500, P1111, P1112, P1114, or P1115 are not set.
2. The ignition voltage is between 10-18 volts.
3. The Barometric Pressure (BARO) is more than 75 kPa.
4. The fuel level is between 15-85 percent.
5. The Engine Coolant Temperature (ECT) is between 39-86° F (4-30° C).
6. The Intake Air Temperature (IAT) is between 39-86° F (4-30° C).
7. The start-up ECT and IAT are within 16° F (9° C) of each other.

1. A continuous open purge flow condition is detected during the diagnostic test.
2. The fuel tank pressure decreases to less than -11 inches H2O.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Scheme 705

1. DTCs P0107, P0108, P0112, P0113, P0117, P0118, P0120, P0125, P0171, P0172, P0200, P0220, P0300, P0442, P0446, P0452, P0453, P0641, P0651, P1514, P1515, P1516 or P2135 are not set.
2. The engine is operating for at least 2 seconds.
3. The Engine Coolant Temperature (ECT) is greater than -40°F (-40°C).
4. The Intake Air Temperature (IAT) is greater than -40°F (-40°C).
5. The Barometric (BARO) pressure is greater than 65 kPa.
6. The system voltage is between 9-18 volts.
7. The vehicle speed is less than 3 MPH.

1. The actual idle speed is 100 RPM less than or 100 RPM more than the desired idle speed.
2. All of the above conditions are present for 15 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The engine is running.

1. The PCM detects a voltage out of tolerance condition on the 5-volt reference circuit.
2. The above condition is present for longer than 2 seconds.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating condition to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Scheme 706

Scheme 707

The engine is running.

1. The control module detects that the commanded start of the MIL driver and the actual state of the control circuit do not match.
2. The conditions are present for a minimum of 30 seconds.

The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. A Last Test Failed, or current DTC, clears when the diagnostic runs and does not fail.
2. A history DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
3. Use a scan tool in order to clear the DTC.

The engine is running.

1. The PCM detects a voltage out of tolerance condition on the 5-volt reference circuit.
2. The above conditions is present for longer than 2 seconds.

Action Take When DTC Sets

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malefaction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Scheme 708

Scheme 709

The engine is running.

The TCM is requesting MIL illumination, or that the MIL request circuit is shorted to ground.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

The ignition is ON.

The PCM is detecting an incorrect voltage level on the TCM request circuit.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunctions Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if not failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Scheme 710

Scheme 711

1. DTC P0120, P0220, P1125, P1514, P1515, P1516, P1518, P2108, P2120, P2121, P2125, P2126, P2130, P2131, P2135 are not set.
2. The engine has been running for a length of time that is determined by the start-up coolant temperature. The length of time ranges from 4 minutes at less than -22° F (-30° C) to 30 seconds at more than 85° F (30° C).
3. The throttle angle is less than 1 percent when the engine speed is less than 1200 RPM.
4. The throttle angle is less than 20 percent when the engine speed is more than 1200 RPM.

The PCM detects that the MAP sensor voltage is more than 4.9 volts.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The Malfunction Indicator Lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, if equipped, may display a message.

Conditions For Clearing DTC

1. A current DTC Last Test Failed clears when the diagnostic runs and passes.
2. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

1. DTC P0120, P0220, P1125, P1514, P1515, P1516, P1518, P2108, P2120, P2121, P2125, P2126, P2130, P2131, or P2135 are not set.
2. The engine is running.
3. The throttle angle is 0 percent when the engine speed is less than 800 RPM.
4. The throttle angle is more than 12.5 percent when engine speed is more than 800 RPM.

The PCM detects that the MAP sensor voltage is less than 0.1 volt.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The Malfunction Indicator Lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, if equipped, may display a message.

1. A current DTC Last Test Failed clears when the diagnostic runs and passes.
2. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

1. DTCs P0101, P0102, P0103, or P0113 are not set.
2. The engine run time is more than 120 seconds.
3. The engine coolant temperature is more than 140°F (60°C).
4. The vehicle speed is less than 7 MPH.
5. The mass air flow is less than 15 g/s.

The intake air temperature is less than -36°F (-38°C) for a calibrated amount of time.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The Malfunction Indicator Lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, if equipped, may display a message.

1. A current DTC Last Test Failed clears when the diagnostic runs and passes.
2. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
3. Clear the MIL and the DTC with a scan tool.

1. An IAT sensor or PCM which is intermittently shorted, open, or skewed is possible, yet very unlikely.
2. A skewed sensor could result in poor driveability conditions.
3. If an intermittent condition is suspected, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

Scheme 712

1. DTCs P0112, P0500, P0502, and P0503 are not set.
2. The engine run time is more than 45 seconds.
3. The vehicle speed is more than 25 MPH.
4. The ECT sensor parameter is less than 257° F (125° C).

The PCM detects that the IAT sensor parameter is more than 252° F (128° C) intermittently for a calibrated amount of time.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The Malfunction Indicator Lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, if equipped, may display a message.

1. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
2. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
3. Clear the MIL and the DTC with a scan tool.

1. An IAT sensor or PCM which is intermittently shorted, open, or skewed is possible, yet very unlikely.
2. A skewed sensor could result in poor driveability complaints.
3. If an intermittent condition is suspected, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

Scheme 713

Engine run time is more than 10 seconds.

The PCM detects that the ECT sensor parameter is more than 282° F (139° C) intermittently for a calibrated amount of time.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The Malfunction Indicator Lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, if equipped, may display a message.

1. A current DTC Last Test Failed clears when the diagnostic runs and passes.
2. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

1. An ECT sensor or PCM which is intermittently shorted, open, or skewed is possible, yet very unlikely.
2. An intermittent short to ground in the ECT sensor signal circuit could result in a DTC P1114.
3. Use the Temperature vs Resistance Value scale in order to test the coolant sensor at various temperature levels in order to evaluate the possibility of a skewed sensor. A skewed sensor could result in poor driveability complaints. See «TEMPERATURE VS. RESISTANCE»(ref-158433-S12013627562003092600000) .
4. If an intermittent condition is suspected, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

Scheme 714

Engine run time is more than 60 seconds.

The PCM detects an ECT of less than -36°F (-38°C), as measured by the ECT sensor for a calibrated amount of time.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The Malfunction Indicator Lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, if equipped, may display a message.

1. A current DTC Last Test Failed clears when the diagnostic runs and passes.
2. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

1. An ECT sensor or PCM which is intermittently shorted, open, or skewed is possible, yet very unlikely.
2. An intermittent open or short to voltage in the ECT sensor signal circuit could result in a DTC P1115.
3. Use the Temperature vs Resistance Value scale in order to test the coolant sensor at various temperature levels in order to evaluate the possibility of a skewed sensor. A skewed sensor could result in poor driveability complaints. See «TEMPERATURE VS. RESISTANCE»(ref-158433-S12013627562003092600000) .
4. If an intermittent condition is suspected, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

Scheme 715

1. DTCs P1517 or P1518 are not set.
2. The ignition switch is in the crank or run position.
3. The ignition voltage is greater than 5.23 volts.

1. Two or more APP sensors are out of range or 2 APP sensors disagree.
2. All of the above conditions present for less than 1 second.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.
3. The control module commands the TAC system to operate in the Reduced Engine Power mode; or, under certain conditions the control module commands the engine OFF.
4. The message center displays Reduced Engine Power.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. Inspect the TAC module connectors for signs of water intrusion. If water intrusion occurs, multiple DTCs may set without any circuit or component conditions found during diagnostic testing.
2. The APP sensor 1 and the Throttle Position (TP) sensor 1, 5-volt reference circuits are internally connected within the TAC module.
3. The APP sensor 2 and the TP sensor 2, 5-volt reference circuits are internally connected within the TAC module.
4. When the TAC module detects a condition within the TAC system more than 1 TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing 1 individual condition may correct more than 1 DTC. Remember this if you review the information stored in Captured Info.
5. If an intermittent condition is suspected, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0131, P0132, P0134, P0135, P0151, P0152, P0154, P0155, P0200, P0220, P0300, P0401, P0404, P0405, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1404, P1514, P1515, P1516, P1518, P2108, or P2135 are not set.
2. The Engine Coolant Temperature (ECT) sensor is more than 140°F (60°C).
3. The engine run time is more than 160 seconds.
4. The Evaporative (EVAP) emissions purge solenoid command is more than 1 percent.
5. The Mass Airflow (MAF) sensor is between 29-55 g/s.
6. The engine speed is between 1000-3000 RPM.
7. For vehicles with TAC, the TP indicated angle is 5 percent more than the value observed at idle.
8. The loop status is Closed.
9. The ignition 1 signal voltage is between 10-18 volts.
10. The fuel tank level remaining is more than 10 percent.
11. The above conditions are met for 100 seconds.

The PCM detects that the affected HO2S lean-to-rich or rich-to-lean transitions are less than a calibrated value.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. DTCs P0461, P0462, P0463, P2066, P2067, or P2068 are not set.
2. The engine is not running.
3. The vehicle speed is 0 MPH.
4. The primary fuel level is less than 6.6 gal. (25 L).
5. The secondary fuel level is more than 0.7-2.6 gal. (3-10 L).
6. The above conditions are met for 20 seconds before the secondary pump is commanded ON.
7. The secondary fuel pump is commanded ON for 120 seconds.

The PCM does not detect a change of 1.06 gal. (4 L) in both the primary and secondary fuel level sensors with the secondary pump commanded ON for 120 seconds.

1. The PCM stores the DTC information into memory when the diagnostic runs and fails.
2. The Malfunction Indicator Lamp (MIL) will not illuminate.
3. The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.

1. A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
2. A history DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
3. Use a scan tool in order to clear the DTC.

1. DTCs P0117, P0118, P1114, and P1115 are not active.
2. The engine is running.

The engine coolant temperature is above 132°C (270°F) for 10 seconds or more.

1. The PCM will illuminate the Malfunction Indicator Lamp (MIL) during the first trip in which the diagnostic test has been run and failed.
2. The PCM will signal the IPC to turn ON the Service Engine Soon indicator.
3. The PCM will alternately disable two groups of four cylinders by turning OFF the fuel injectors.
4. The PCM will store conditions which were present when the DTC set as Freeze Frame and File Records data.

1. The PCM will turn the MIL OFF after 3 consecutive trips that the diagnostic has been run and passed.
2. The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
3. The DTC can be cleared by using the scan tool Clear DTC Information function.

Scheme 716

1. DTCs P0101, P0102, P0103, P0120, P0335, P0336, or P0742 are not set.
2. The vehicle speed is more than 10 MPH.
3. The engine load is less than 60 percent.
4. The engine misfire is detected and DTC P0300 set.
5. The engine speed is less than 3200 RPM.

An ABS malfunction exists preventing the PCM from receiving rough road detection data.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The Malfunction Indicator Lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, if equipped, may display a message.

1. A current DTC Last Test Failed clears when the diagnostic runs and passes.
2. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

Scheme 717

1. The engine load is less than 60 percent.
2. The engine speed is less than 3200 RPM.
3. The vehicle speed is more than 10 MPH.
4. Engine misfire is detected and DTC P0300 is set.

1. A serial data malfunction exists preventing the PCM from receiving rough road detection data.
2. The above conditions are met for 20 seconds.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The Malfunction Indicator Lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, if equipped, may display a message.

1. A current DTC Last Test Failed clears when the diagnostic runs and passes.
2. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

1. The ignition 1 signed parameter is between 11-18 volts.
2. The PCM has enabled the EGR valve.
3. The above conditions are met 3 times.

1. EGR position sensor is 0.29 volts more than the EGR learned minimum position when the desired EGR position is commanded to 0 percent.
2. The vehicle must be driven.
3. The condition has to be present 3 times.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Inspect for excessive deposits on the EGR valve pintle or seat. Remove the EGR valve and check for deposits that may interfere with the EGR valve pintle extending completely or cause the pintle to stick.

If DTC is determined to be intermittent, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.

1. DTCs P0601, P0602, P0604, P0606, P1515, P1516, P1517, or P1518 are not set.
2. The following DTCs are not active at the same time: P0120, P0220 and P2135.
3. The following DTCs are not active at the same time: P0120 and P0220.
4. The engine operates longer than 1 second.
5. The engine speed is greater than 500 RPM.

1. The PCM detects that the difference between the actual airflow (MAF) and the Speed Density calculated air flow is greater than expected.
2. All of the above conditions met for less than 1 second.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.
3. The control module commands the TAC system to operate in the Reduced Engine Power mode; or, under certain conditions the control module commands the engine OFF.
4. The message center displays Reduced Engine Power.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. Inspect the throttle blade for being broken, bent, or missing.
2. Inspect the Throttle Position (TP) sensor for proper installation. A sensor that is mis-aligned could set this DTC.
3. Inspect the Throttle Actuator Control (TAC) module connectors for signs of water intrusion. If water intrusion occurs, multiple DTCs may set without any circuit or component conditions found during diagnostic testing.
4. Physically and visually inspect the throttle body assembly and correct any problems that you observe. Manually move the throttle blade from closed to Wide Open Throttle (WOT). You should not need to use excess force. The throttle blade should move smoothly through the full range and then should independently return to a slightly open position.
5. When the TAC module detects a condition within the TAC system, more than 1 TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing 1 individual condition may correct more than 1 DTC. Disconnecting components during testing may set additional DTCs. Remember this if you review the stored information in Capture Info.
6. For an Intermittent condition, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

1. DTCs P0601, P0602, P0604, P0606, P1516, P1518 or P2108 are not set.
2. The following DTCs are not active at the same time: P0120, P0220 and P2135.
3. The following DTCs are not active at the same time: P0120 and P0220.
4. The ignition switch is in the crank or run position.
5. The ignition voltage is greater than 8.5 volts.
6. The TAC system is not in the battery saver mode.

1. The PCM detects that the commanded and actual throttle positions are not within a calibrated range of each other.
2. All above conditions met for less than 1 second.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.
3. The control module commands the TAC system to operate in the Reduced Engine Power mode; or, under certain conditions the control module commands the engine OFF.
4. The message center displays Reduced Engine Power.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. Inspect for mechanical concerns or binding that may be temperature related. Components may not move freely in extreme heat or cold due to the presence of contaminants or ice formation.
2. Inspect the TAC module connectors for signs of water intrusion. If water intrusion occurs, multiple DTCs may set without any circuit or component conditions found during diagnostic testing.
3. When the TAC module detects a condition within the TAC system, more than 1 TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing an individual condition may correct more than 1 DTC. Disconnecting components during testing may set additional DTCs. Remember this if you review the stored information in Capture Info.
4. For an Intermittent condition, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

1. DTC P1518 is not set.
2. The ignition switch is in the crank or run position.
3. The ignition voltage is greater than 5.23 volts.
4. The TAC system is not in the battery saver mode.

1. The TAC module detects that the predicted and actual throttle positions are not within a calibrated range of each other or the PCM and the TAC cannot determine throttle position or both TP sensors are invalid.
2. All of the above conditions met for less than 1 second.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.
3. The control module commands the TAC system to operate in the Reduced Engine Power mode; or, under certain conditions the control module commands the engine OFF.
4. The message center displays Reduced Engine Power.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. Inspect the TAC module connectors for signs of water intrusion. If water intrusion occurs, multiple DTCs may set without any circuit or component conditions found during diagnostic testing.
2. Verify that the starting and charging systems are operating properly. Low system voltage can cause this DTC to set.
3. When the TAC module detects a condition within the TAC system, more than 1 TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing an individual condition may correct more than 1 DTC. Disconnecting components during testing may set additional DTCs. Remember this if you review the stored information in Capture Info.
4. For an Intermittent condition, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

1. The ignition switch is in the crank or run position.
2. The ignition voltage is greater than 5.23 volts.

1. Invalid or missing serial data messages are detected for a predetermined amount of time.
2. All of the above conditions met for more than 1 second.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.
3. The control module commands the TAC system to operate in the Reduced Engine Power mode; or, under certain conditions the control module commands the engine OFF.
4. The message center displays Reduced Engine Power.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC P1518 sets

1. If the battery voltage is low. If the customer's concern is slow cranking or no crank because battery voltage is low, ignore DTC P1518. Clear any DTCs from memory that may have set from the low battery voltage condition.
2. When there is a short to battery voltage on the TAC module ground circuit. Inspect the fuses for the circuits that are in the TAC module harness, (i.e., cruise or brake). An inspection of the fuses may lead you to the circuit that is shorted to the TAC module ground circuit.
3. If the TAC module ignition feed circuit is shorted to a battery voltage supply circuit. The TAC module stays powered-up when the ignition switch is turned OFF. When the ignition switch is turned ON, the TAC module is powered-up before the PCM. DTC P1518 sets because no communication is detected by the TAC module from the PCM. Inspect related circuits for being shorted to a battery voltage supply circuit.

Inspect the TAC module power and ground circuits and the TAC module/PCM serial data circuits for intermittent connections.

Inspect the TAC module connectors for signs of water intrusion. If water intrusion occurs, multiple DTCs may set without any circuit or component conditions found during diagnostic testing.

When the TAC module detects a problem within the TAC system, more than 1 TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing an individual condition may correct more than 1 DTC. Remember this if you review the stored information in Capture Info.

For an Intermittent condition, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.

1. DTC P1518 is not set.
2. The ignition switch is in the crank or run position.
3. The ignition voltage is greater than 6 volts.

1. The TAC module determines than an internal data test did not pass.
2. The above condition is met for more than 1 second.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostics fails. The control module stores this information in the Freeze Frame and/or the Failure Records.
3. The control module commands the TAC system to operate in the Reduced Engine Power mode.
4. Under certain conditions the control module commands the engine OFF.
5. The message center displays Reduced Engine Power.

1. The control module turns off the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

1. Verify that the starting and charging systems are operating properly. Low system voltage can cause this DTC to set.
2. Inspect the TAC module connectors for signs of water intrusion. If water intrusion occurs, multiple DTCs may set without any circuit or component conditions found during diagnostic testing.
3. When the TAC module detects a condition within the TAC system, more than 1 TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing an individual conditions may correct more than 1 DTC. Disconnecting components during testing may set additional DTCs. Remember this if you review the stored information in Capture Info.

1. DTCs P0601, P0602, P1518, or P2108 are not set.
2. The ignition switch is in the crank or run position.
3. The ignition voltage is more than 5.23 volts.

1. The APP sensor 1 voltage is less than 0.24 volts or more than 4.49 volts.
2. The 5-volt reference is less than 4.54 volts or more than 5.21 volts.
3. One of the above conditions is present for more than 1 second.

1. The control module stored the DTC information into memory when the diagnostic runs and fails.
2. The Malfunction Indicator Lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. If one or more APP sensor DTCs are set, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to a predetermined value to limit the amount or throttle control. The APP indicated angle is limited to 0 percent. The control module only allows the engine to idle. The message center displays Reduced Engine Power.

1. A current DTC Last Test Failed clears when the diagnostic runs and passes.
2. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

1. Inspect the Throttle Actuator Control (TAC) module connectors for signs of water intrusion. If water intrusion occurs, multiple DTCs may set without any circuit or component conditions found during diagnostic testing.
2. When the TAC module detects a condition within the TAC system, more than 1 TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing 1 individual condition may correct more than 1 DTC. Disconnecting components during testing may set additional DTCs. Remember this if you review the stored information in Capture Info.
3. For an Intermittent condition, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

1. DTCs P0606, P1518 or P2108 are not set.
2. The ignition switch is in the crank or run position.
3. The ignition volage is more than 5.23 volts.

1. APP sensor 1 disagrees with APP sensor 2 by more than 10.5 percent.
2. The above condition is present for more than 1 second.

1. The control module stored the DTC information into memory when the diagnostic runs and fails.
2. The Malfunction Indicator Lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. If one or more APP sensor DTCs are set, the following occurs: The control module commands Reduced Engine Power mode. The APP indicated angle is limited to a predetermined value to limit the amount or throttle control. The APP indicated angle is limited to 0 percent. The control module only allows the engine to idle. The message center displays Reduced Engine Power.

1. A current DTC Last Test Failed clears when the diagnostic runs and passes.
2. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

1. Inspect the Throttle Actuator Control (TAC) module connectors for signs of water intrusion. If water intrusion occurs, multiple DTCs may set without any circuit or component conditions found during diagnostic testing.
2. When the TAC module detects a condition within the TAC system, more than 1 TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing 1 individual condition may correct more than 1 DTC. Disconnecting components during testing may set additional DTCs. Remember this if you review the stored information in Capture Info.
3. For an Intermittent condition, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

1. DTCs P0601, P0602, P0606, P1518 or P2108 are not set.
2. The ignition switch is in the crank or run position.
3. The ignition voltage is more than 5.23 volts.

1. The APP sensor 2 voltage is less than 0.24 volt or more than 4.49 volts.
2. The 5-volt reference is less than 4.54 volts or more than 5.21 volts.
3. One of the above conditions is present for more than 1 second.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The Malfunction Indicator Lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. If one or more APP sensor DTCs are set, the following occurs: The control module commands Reduced Engine Power mode. the APP indicated angle is limited to a predetermined value to limit the amount of throttle control. The APP indicated angle is limited to 0 percent. The control module only allows the engine to idle. The message center displays Reduced Engine Power.

1. A current DTC Last Test Failed clears when the diagnostic runs and passes.
2. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with the scan tool.

1. Inspect the Throttle Actuator Control (TAC) module connectors for signs or water intrusion. If water intrusion occurs, multiple DTCs may set without any circuit or component conditions found during diagnostic testing.
2. When the TAC module detects a condition within the TAC system, more than 1 TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing 1 individual condition may correct more than 1 DTC. Disconnecting components during testing may set additional DTCs. Remember this if you review the stored information in Capture Info.
3. For an Intermittent condition, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.

1. DTCs P1518 or P2108 are not set.
2. The ignition switch is in the crank or run position.
3. The ignition voltage is more than 5.23 volts.

1. The TP sensor 2 disagrees with the TP sensor 1 by more than 7.5 percent.
2. The above condition is present for more than 1 second.

1. The control module illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.
3. The control module commands the TAC system to operate in the Reduced Engine Power mode.
4. Under certain conditions the control module commands the engine OFF.
5. The message center displays Reduced Engine Power.

1. The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL/DTC with a scan tool.

1. Inspect the Throttle Actuator Control (TAC) module connectors for signs of water intrusion. If water intrusion occurs, multiple DTCs may set without any circuit or component conditions found during diagnostic testing.
2. When the TAC module detects a condition within the TAC system, more than 1 TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing 1 individual condition may correct more than 1 DTC. Disconnecting components during testing may set additional DTCs. Remember this if you review the stored information in Capture Info.
3. For an Intermittent condition, see «INTERMITTENT CONDITIONS»(ref-158433-S14921667092003092600000) under SELF-DIAGNOSTIC SYSTEM.