Action Taken When the DTC Sets - Type A
The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
Action Taken When the DTC Sets - Type B
The control module illuminates the MIL on the second consecutive ignition cycle that the diagnostic runs and fails.
Conditions for Clearing the MIL/DTC - Type A or Type B
- The control module turns OFF the MIL after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC Last Test Failed clears when the diagnostic runs and passes.
- Use a scan tool in order to clear the MIL and the DTC.
Action Taken When the DTC Sets - Type C
- The control module stores the DTC information into memory when the diagnostic runs and fails.
- The MIL will not illuminate.
- The driver information center, if equipped, may display a message.
Conditions for Clearing the DTC - Type C
- A last test failed, or current DTC, clears when the diagnostic runs and passes.
- Use a scan tool in order to clear the DTC.
Conditions for Clearing the DTC - Type X
This DTC is available in the PCM software, but has been disabled, or turned OFF. In this case, the diagnostic does not run, no DTCs are stored, and the MIL does not illuminate. Type X DTCs are used primarily for export vehicles that do not require MIL illumination or DTC storing.
Diagnostic Trouble Code (DTC) Type(s)
| Diagnostic Trouble Code (DTC) | Federal RPO NF2 or NT9 | California RPO NB6, NC1, or NC8 |
|---|---|---|
| P0068 | A | A |
| P0101 | B | B |
| P0102 | B | B |
| P0103 | B | B |
| P0106 | B | B |
| P0107 | B | B |
| P0108 | B | B |
| P0112 | B | B |
| P0113 | B | B |
| P0116 | X | B |
| P0117 | B | B |
| P0118 | B | B |
| P0120 | A | A |
| P0125 | X | B |
| P0128 | X | B |
| P0131 | B | B |
| P0132 | B | B |
| P0133 | X | B |
| P0134 | B | B |
| P0135 | X | B |
| P0136 | X | B |
| P0137 | X | B |
| P0138 | X | B |
| P0140 | X | B |
| P0141 | X | B |
| P0151 | B | B |
| P0152 | B | B |
| P0153 | X | B |
| P0154 | B | B |
| P0155 | X | B |
| P0156 | X | B |
| P0157 | X | B |
| P0158 | X | B |
| P0160 | X | B |
| P0161 | X | B |
| P0171 | B | B |
| P0172 | B | B |
| P0174 | B | B |
| P0175 | B | B |
| P0200 | B | B |
| P0218 | C | C |
| P0220 | A | A |
| P0230 | B | B |
| P0300 | B | B |
| P0315 | A | A |
| P0325 | B | B |
| P0327 | B | B |
| P0332 | B | B |
| P0335 | B | B |
| P0336 | B | B |
| P0341 | B | B |
| P0342 | B | B |
| P0343 | B | B |
| P0351-P0358 | B | B |
| P0420 | X | A |
| P0430 | X | A |
| P0442 | X | A |
| P0443 | B | B |
| P0446 | X | A |
| P0449 | X | B |
| P0452 | X | B |
| P0453 | X | B |
| P0455 | X | A |
| P0461 | C | C |
| P0462 | C | C |
| P0463 | C | C |
| P0496 | X | B |
| P0500 | B | B |
| P0506 | B | B |
| P0507 | B | B |
| P0522 | C | C |
| P0523 | C | C |
| P0530 | C | C |
| P0562 | C | C |
| P0563 | C | C |
| P0567 | C | C |
| P0568 | C | C |
| P0571 | C | C |
| P0601 | A | A |
| P0602 | A | A |
| P0604 | A | A |
| P0606 | A | A |
| P0608 | C | C |
| P0609 | C | C |
| P0622 | C | C |
| P0641 | B | B |
| P0650 | B | B |
| P0651 | B | B |
| P0654 | C | C |
| P0700 | A | A |
| P0706 | C | C |
| P0802 | B | B |
| P0833 | B | B |
| P0856 | B | B |
| P1106 | C | C |
| P1107 | C | C |
| P1111 | C | C |
| P1112 | C | C |
| P1114 | C | C |
| P1115 | C | C |
| P1125 | A | A |
| P1133 | X | B |
| P1134 | X | B |
| P1153 | X | B |
| P1154 | X | B |
| P1258 | A | A |
| P1380 | X | C |
| P1381 | X | C |
| P1516 | A | A |
| P1574 | C | C |
| P1626 | C | C |
| P1631 | C | C |
| P1637 | C | C |
| P1875 | C | B |
| P2067 | C | C |
| P2068 | C | C |
| P2101 | A | A |
| P2108 | A | A |
| P2120 | C | C |
| P2121 | C | C |
| P2125 | C | C |
| P2135 | A | A |
| P2610 | B | B |
| P2636 | C | C |
| P2771 | C | B |
| U0107 | A | A |
Diagnostic Trouble Code (DTC) Type(s)
Scheme 128
| Callout | Component Name |
|---|---|
| 1 | Fuel Pressure Dampener |
| 2 | EVAP Purge Pipe |
| 3 | EVAP Purge Solenoid Valve |
| 4 | Throttle Body |
Scheme 129
| Callout | Component Name |
|---|---|
| 1 | EVAP Canister Purge Solenoid Valve |
| 2 | EVAP Canister |
| 3 | Fuel Fill Neck/Fill Cap |
| 4 | Rollover Valve/Fuel Tank Pressure (FTP) Sensor |
| 5 | Fuel Tank |
| 6 | EVAP Canister Vent Solenoid Valve |
| 7 | Vent Hose/Pipe |
| 8 | EVAP Vapor Pipe |
| 9 | EVAP Purge Pipe |
| 10 | EVAP Service Port |
Scheme 130
| Callout | Component Name |
|---|---|
| 1 | Fuel Pressure Service Connection |
| 2 | Fuel Injector Rail |
| 3 | Fuel Rail Feed Pipe |
| 4 | Fuel Feed Hose |
| 5 | Fuel Injector |
Inspection Procedure
Note. Use the EVAP Pressure/Purge Diagnostic Station J 41413 in order to provide a clean, dry, low pressure gas source. Do not substitute any other pressurized gas source. Damage may result to the EVAP system.
| IMPORTANT | DO NOT perform this procedure unless instructed by an EVAP diagnostic. |
- Turn OFF the ignition.
- Remove the EVAP canister purge valve. Refer to «Evaporative Emission (EVAP) Canister Purge Solenoid Valve Replacement»(ref-184137-S03573160122005082200000) .
- Lightly tap the EVAP canister purge valve on a clean hard surface.
- Inspect for carbon particles exiting either of the vacuum ports. If no carbon particles are found, install the EVAP canister purge valve and continue with the EVAP cleaning procedure. If carbon particles are found during the inspection procedure, continue with the EVAP cleaning procedure. If you were instructed to replace the EVAP canister purge valve, and no carbon particles are found, return to the EVAP diagnostic procedure. Do not perform the EVAP cleaning procedure.
Spark Plug Wire Inspection
Spark plug wire integrity is vital for proper engine operation. A thorough inspection is necessary to accurately identify conditions that may affect engine operation. Inspect for the following conditions
- Correct routing of the spark plug wires. Incorrect routing may cause cross-firing.
- Any signs of cracks or splits in the wires.
- Inspect each boot for the following conditions: Tearing Piercing Arcing Carbon tracking Corroded terminal
If corrosion, carbon tracking or arcing are indicated on a spark plug wire boot or terminal, replace the wire and the component connected to the wire.
Scheme 131
- Disconnect the spark plug wire at the spark plug. Twist the spark plug wire 1/2 turn. Pull only on the boot in order to remove the wire from the spark plug.
- Disconnect the spark plug wire from the ignition coil. Twist each spark plug boot 1/2 turn. Pull only on the boot in order to remove the wire from the ignition coil.
Visual Inspection
- Normal operation-Brown to grayish-tan with small amounts of white powdery deposits are normal combustion by-products from fuels with additives.
- 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.
- 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.
Scheme 132
- Remove the spark plug wire. Refer to «Spark Plug Wire Replacement»(ref-184137-S37863825142005082200000) .
- Loosen the spark plug 1 or 2 turns.
- Brush or using compressed air, blow away any dirt from around the spark plug.
- Remove the spark plug. If removing more than one plug, place each plug in a tray marked with the corresponding cylinder.
Scheme 133
- Correctly position the spark plug washer.
- Inspect the spark plug gap. Adjust the gap as needed. Specification: Spark plug gap: 1.524 mm (0.060 in)
- Hand start the spark plug in the corresponding cylinder. NOTE: Refer to Fastener Notice in Cautions and Notices.
- Tighten the spark plug. Tighten: Tighten the plug to 20 N.m (15 lb ft) for USED heads. Tighten the plug to 30 N.m (22 lb ft) for NEW heads.
- Install the spark plug wire. Refer to «Spark Plug Wire Replacement»(ref-184137-S37863825142005082200000) .
Diagnostic Trouble Codes (DTCs)
The powertrain control module (PCM) is programmed with test routines that test the operation of the various systems the PCM controls. Some tests monitor internal PCM 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 PCM 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 PCM executes the Action Taken When the DTC Sets. Some DTCs alert the driver via the malfunction indicator lamp (MIL) or a message. Other DTCs do not trigger a driver warning, but are stored in memory. The PCM 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.
DTC Status
When the scan tool displays a DTC, the status of the DTC is also displayed. The following DTC statuses are indicated only when they apply to the DTC that is set.
Scheme 134
| Callout | Component Name |
|---|---|
| 1 | Throttle Actuator Control (TAC) Module |
| 2 | Throttle Body Assembly |
| 3 | Accelerator Pedal Position (APP) Sensor |
The throttle actuator control (TAC) system uses vehicle electronics and components to calculate and control the position of the throttle blade. This eliminates the need for a mechanical cable attachment from the accelerator pedal to the throttle body. This system also performs the cruise control functions as well.
The TAC system components include the following
- The accelerator pedal position (APP) sensor
- The throttle body
- The throttle actuator control (TAC) module
- The powertrain control module (PCM)
Each of these components interface together to ensure accurate calculations and control of the throttle position.
Scheme 135
The APP sensor is mounted on the accelerator pedal assembly. The APP is actually 3 individual accelerator pedal position sensors within one housing. Three separate signal, low reference, and 5.0-volt reference circuits are used to connect the APP and the TAC module. The APP sensor 1 voltage should increase as the accelerator pedal is depressed, from below 1.0 volt at 0 percent pedal travel to above 2.0 volts at 100 percent pedal travel. APP sensor 2 voltage should decrease from above 4.0 volts at 0 percent pedal travel to below 2.9 volts at 100 percent pedal travel. APP sensor 3 voltage should decrease from above 3.8 volts at 0 percent pedal travel to below 3.1 volts at 100 percent pedal travel.
Scheme 136
The throttle body for the TAC system is similar to a conventional throttle body with a couple of exceptions. One exception being the use of a motor to control the throttle position instead of a mechanical cable. The other exception is the new design throttle position (TP) sensor. The TP sensor mounts on the side of the throttle body opposite the throttle actuator motor. The TP sensor is actually 2 individual TP sensors within one housing. Separate signal, low reference, and 5.0-volt reference circuits are used to connect the TP sensors and the TAC module. The TP sensor 1 signal voltage increases as the throttle opens, from around 1.0 volt at 0 percent throttle to above 3.5 volts at 100 percent throttle. TP sensor 2 signal voltage decreases as the throttle is opened, from around 3.8 volts at 0 percent throttle to below 1.0 volt at 100 percent throttle.
Scheme 137
The TAC module is the control center for the electronic throttle system. The TAC module and the PCM communicate via a dedicated redundant serial data circuit. The TAC module and the PCM monitor the commanded throttle position and compare the commanded position to the actual throttle position. This is accomplished by monitoring the APP and the TP sensor. These 2 values must be within a calibrated value of each other. The TAC module also monitors each individual circuit of the TP sensor and the APP to verify proper operation.
Large Leak Test
This tests for large leaks and blockages in the evaporative emission (EVAP) system. The control module commands the EVAP vent solenoid valve ON and commands the EVAP purge solenoid valve ON, with the engine running, allowing engine vacuum into the EVAP system. The control module monitors the fuel tank pressure (FTP) sensor voltage 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 solenoid valve OFF, 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 rate is more than a calibrated level on 2 consecutive tests, DTC P0455 will set.
Small Leak Test
The engine off natural vacuum (EONV) diagnostic is the small-leak detection diagnostic for the evaporative emission (EVAP) system. While previous leak detection methods were performed with the engine running, the EONV diagnostic monitors the EVAP system pressure or vacuum with the ignition OFF. Because of this, it may be normal for the control module to remain active for up to 40 minutes after the ignition is turned OFF. This is important to remember when performing a parasitic draw test on vehicles equipped with EONV.
The EONV utilizes the temperature changes in the fuel tank immediately following a drive cycle to use the naturally occurring vacuum or pressure in the fuel tank. When the vehicle is driven, the temperature rises in the tank. After the vehicle is parked, the temperature in the tank continues to rise for a period of time, then starts to drop. The EONV diagnostic relies on this temperature change and the corresponding pressure change in a sealed system, to determine if an EVAP system leak is present.
The EONV diagnostic is designed to detect leaks as small as 0.51 mm (0.020 in). The diagnostic can determine if a small leak is present based on vacuum or pressure readings in the EVAP system. When the system is sealed, a finite amount of pressure or vacuum will be observed. When a 0.51 mm (0.020 in) leak is present, often little or no pressure or vacuum is observed. If the test reports a failing value, DTC P0442 will set.
Canister Vent Restriction Test
If the evaporative emission (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 solenoid valve ON, commanding the EVAP vent solenoid valve OFF, and monitoring the fuel tank pressure (FTP) sensor for an increase in vacuum. If the vacuum increases more than a calibrated value, DTC P0446 will set.
Purge Solenoid Valve Leak Test
If the evaporative emission (EVAP) purge solenoid 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 solenoid valve OFF and the vent solenoid valve ON, sealing the system, and monitors the fuel tank pressure (FTP) for an increase in vacuum. If the control module detects that the EVAP system vacuum increases above a calibrated value, DTC P0496 will set.