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Engine Controls (Introduction) -- 2.2L (L61): Diagnosis Saturn VUE I

Testing & Diagnostics 2 illustrations ~1054 words

Diagnostic Trouble Code (DTC) Type(s)

Diagnostic Trouble Code (DTC)DomesticExport Unleaded Fuel
P0068AA
P0106BB
P0107BB
P0108BB
P0112BB
P0113BB
P0117BB
P0118BB
P0120AA
P0122BB
P0123BB
P0125BB
P0128BB
P0130BB
P0131BB
P0132BB
P0133BB
P0134BB
P0135BB
P0136BB
P0137BB
P0138BB
P0140BB
P0141BB
P0171BB
P0172BB
P0201-P0204BB
P0220AA
P0222AA
P0223AA
P0300Type B EMISSION Type A CATALYSTB
P0301-P0304Type B EMISSION Type A CATALYSTB
P0315AA
P0326BB
P0327BB
P0336BB
P0340BB
P0341BB
P0420AA
P0442AA
P0446AA
P0452AA
P0453AA
P0455AA
P0461CC
P0462CC
P0463CC
P0480BB
P0481BB
P0496AA
P0502BB
P0506BB
P0507BB
P0530CC
P0562CC
P0563CC
P0567CC
P0568CC
P0571CC
P0601AA
P0602AA
P0604AA
P0606AA
P0607CC
P0621CC
P0641AA
P0651AA
P0856CC
P1133BB
P1137BB
P1138BB
P1171CC
P1516AA
P1574DD
P1599DD
P1621AA
P1630CC
P1631CC
P1640CC
P1650
P1670BB
P1680AA
P1681AA
P1682AA

Diagnostic Trouble Code (DTC) Type(s)

Scheme 18

Scheme 18: Emission Hose Routing Diagram
CalloutComponent Name
1EVAP Canister Purge Solenoid Valve
2To EVAP Canister
3Throttle Body
4To Intake Manifold

Scheme 19

Scheme 19: Evaporative Emissions (EVAP) Hose Routing Diagram
CalloutComponent Name
1Fuel Tank Pressure (FTP) Sensor
2Fuel Tank
3Evaporative Emission (EVAP) Vent Solenoid Valve
4EVAP Canister
5EVAP Service Port
6EVAP Purge Solenoid Valve
7Fill Limit Vent Valve (FLVV)
8Grade Vent Valve

Spark Plug Inspection

  1. Inspect the terminal post (1) for damage. Inspect for a bent or broken terminal post (1). Test for a loose terminal post (1) by twisting and pulling the post. The terminal post (1) should NOT move.
  2. Inspect the insulator (2) for flashover or carbon tracking, soot. This is caused by the electrical charge traveling across the insulator (2) between the terminal post (1) and ground. Inspect for the following conditions: Inspect the spark plug boot for damage. Inspect the spark plug recess area of the cylinder head for moisture, such as oil, coolant, or water. A spark plug boot that is saturated causes arcing to ground.
  3. Inspect the insulator (2) for cracks. All or part of the electrical charge may arc through the crack instead of the electrodes (3, 4).
  4. Inspect for evidence of improper arcing. Measure the gap between the center electrode (4) and the side electrode (3) terminals. Refer to «Ignition System Specifications»(ref-188786-S18194948442005090200000) . An excessively wide electrode gap can prevent correct spark plug operation. Inspect for the correct spark plug torque. Refer to «Ignition System Specifications»(ref-188786-S18194948442005090200000) . Insufficient torque can prevent correct spark plug operation. An over torqued spark plug, causes the insulator (2) to crack. Inspect for signs of tracking that occurred near the insulator tip instead of the center electrode (4). Inspect for a broken or worn side electrode (3). Inspect for a broken, worn, or loose center electrode (4) by shaking the spark plug. A rattling sound indicates internal damage. A loose center electrode (4) reduces the spark intensity. Inspect for bridged electrodes (3, 4). Deposits on the electrodes (3, 4) reduce or eliminates the gap. Inspect for worn or missing platinum pads on the electrodes (3, 4) If equipped. Inspect for excessive fouling.
  5. Inspect the spark plug recess area of the cylinder head for debris. Dirty or damaged threads can cause the spark plug not to seat correctly during installation.

Spark Plug Visual Inspection

  1. Normal operation-Brown to grayish-tan with small amounts of white powdery deposits are normal combustion by-products from fuels with additives.
  2. Carbon Fouled-Dry, fluffy black carbon, or soot caused by the following conditions: Rich fuel mixtures Leaking fuel injectors Excessive fuel pressure Restricted air filter element Incorrect combustion Reduced ignition system voltage output Weak coils Worn ignition wires Incorrect spark plug gap Excessive idling or slow speeds under light loads can keep spark plug temperatures so low that normal combustion deposits may not burn off.
  3. Deposit Fouling-Oil, coolant, or additives that include substances such as silicone, very white coating, reduces the spark intensity. Most powdery deposits will not effect spark intensity unless they form into a glazing over the electrode.

Diagnostic Trouble Codes (DTCs)

The ECM is programmed with test routines that test the operation of the various systems the ECM controls. Some tests monitor internal ECM functions. Many tests are run continuously. Other tests run only under specific conditions, referred to as Conditions for Running the DTC. When the vehicle is operating within the conditions for running a particular test, the ECM monitors certain parameters and determines if the values are within an expected range. The parameters and values considered outside the range of normal operation are listed as Conditions for Setting the DTC. When the Conditions for Setting the DTC occur, the ECM executes the Action Taken When the DTC Sets. Some DTCs alert the driver via the MIL or a message. Other DTCs do not trigger a driver warning, but are stored in memory. The ECM also saves data and input parameters when most DTCs are set. This data is stored in the Freeze Frame and/or Failure Records.

The DTCs are categorized by type. The DTC type is determined by the MIL operation and the manner in which the fault data is stored when a particular DTC fails. In some cases there may be exceptions to this structure. Therefore, when diagnosing the system it is important to read the Action Taken When the DTC Sets and the Conditions for Clearing the DTC in the supporting text.

There are different types of DTCs and different actions taken when the DTCs set. Refer to Diagnostic Trouble Code (DTC) Type Definitions for a description of the general characteristics of each DTC type.

Large Leak Test

This tests for large leaks and blockages in the EVAP system. The control module will command the EVAP vent valve ON, closed, and command the EVAP purge valve ON, open, with the engine running, allowing engine vacuum into the EVAP system. The control module monitors the fuel tank pressure (FTP) sensor to verify that the system is able to reach a predetermined level of vacuum within a set amount of time. The control module then commands the EVAP purge valve OFF, closed, sealing the system and monitors the vacuum level for decay. If the control module does not detect that the predetermined vacuum level was achieved, or the vacuum decay is more than a calibrated level on 2 consecutive tests, a DTC P0440 will set.

Small Leak Test

If the large leak test passes, the control module will test for small leaks by continuing to monitor the FTP sensor for a change in voltage over a period of time. If the decay rate is more than a calibrated value, the control module will rerun the test. If the test fails again, a DTC P0442 will set.

Canister Vent Restriction Test

If the EVAP vent system is restricted, fuel vapors will not be properly purged from the EVAP canister. The control module tests this by commanding the EVAP purge valve ON, open, and commanding the EVAP vent valve OFF, open, and monitoring the FTP sensor for an increase in vacuum. If vacuum increases more than a calibrated value, DTC P0446 will set.

Purge Valve Leak Test

If the EVAP purge valve does not seal properly, fuel vapors could enter the engine at an undesired time causing driveability concerns. The control module tests for this by commanding the EVAP purge valve OFF, closed, and vent valve OFF, open, sealing the system, and monitoring the FTP for an increase in vacuum. If the control module detects that EVAP system vacuum increases above a calibrated value, DTC P1441 will set.