Circuit Description
The PCM uses output driver modules (ODMs) to control many functions of the engine, and the transaxle. The ODMs supply the ground path for the PCM controlled device when the PCM commands the device ON. Each ODM is able to control several outputs. Unlike the quad driver modules (QDMs) used in earlier model years, the ODMs are able to diagnose each output circuit. The PCM monitors the ODMs for circuit conditions that are incorrect for the commanded state of the ODM. If the PCM detects an improper circuit condition in the ODM that controls the EVAP purge solenoid valve, DTC P0443 will set.
Conditions for Running the DTC
| • | The engine is running. |
| • | System voltage is between 8 and 16 volts. |
Conditions for Setting the DTC
| • | The PCM detects an improper voltage level on the output circuit that controls the EVAP purge solenoid valve. |
| • | The condition exists for at least 10 seconds. |
Action Taken When the DTC Sets
| • | The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test runs and fails. |
| • | The PCM stores the conditions present when the DTC set as Freeze Frame/Failure Records data. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn the MIL OFF after the third consecutive trip in which the diagnostic runs and passes. |
| • | The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using the scan tool Clear DTC Information function. |
Diagnostic Aids
Notice: Use the connector test adapter kit J 35616-A for any test that
requires probing the following items:
• The PCM harness connectors • The electrical center fuse/relay cavities • The component terminals • The component harness connector
To determine whether an improper voltage level exists on the output circuit, the PCM compares the voltage level to the commanded state. For example, a failure condition exists if the PCM detects a low voltage level when the device is commanded OFF, or a high voltage level when the device is commanded ON.
Check for the following conditions:
| • | Poor connections at the PCM or the EVAP purge solenoid valve--Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
| • | Damaged harness--Inspect the wiring harness for damage. If the harness appears to be OK, disconnect the PCM and turn the ignition ON. Connect a voltmeter between the EVAP purge solenoid control circuit and chassis ground. Turn the ignition ON and observe the voltmeter while moving connectors and wiring harnesses related to the EVAP purge solenoid. A change in voltage will indicate the location of the malfunction. If a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems. |
Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may assist in diagnosing the condition. The information may help determine how often the condition that set the DTC occurs.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
Normally, ignition feed voltage should be present on the control circuit with the PCM disconnected and the ignition turned ON.
-
Checks for a shorted component or a short to B+ on the control circuit. Either condition would result in a measured current of over 500 milliamps. Also checks for a component that is going open while being operated, resulting in a measured current of 0 milliamps.
-
Checks for a short to voltage on the control circuit.
-
This vehicle is equipped with a PCM which utilizes an electrically erasable programmable read only memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.
Step | Action | Values | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||||||||
Is voltage near the specified value? | B+ | |||||||||
Does the current reading remain between the specified values? | 0.05-0.5 amps (50-500 mA) | |||||||||
Is voltage at the specified value? | 0 V | |||||||||
5 | Locate and repair the short to voltage in the EVAP purge valve control circuit. Refer to Wiring Repairs in Wiring Systems. Is action complete? | -- | -- | |||||||
6 | Check the ignition feed fuse for the EVAP purge valve. Is the fuse open? | -- | ||||||||
7 |
Was a problem found? | -- | ||||||||
8 |
Is voltage near the specified value? | B+ | ||||||||
9 |
Was a problem found? | -- | ||||||||
10 |
Was a problem found? | -- | ||||||||
11 |
Does the DMM display a voltage near the first value when the EVAP purge valve is commanded ON, and a voltage near the second value when commanded OFF? | B+ 0V | Go to Diagnostic Aids | |||||||
12 |
Was a problem found? | -- | ||||||||
13 | Locate and repair open in ignition feed circuit to the EVAP purge valve. Refer to Wiring Repairs in Wiring Systems. Is action complete? | -- | -- | |||||||
14 | Replace the EVAP purge valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement . Is action complete? | -- | -- | |||||||
|
Important:: Replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is action complete? | -- | -- | ||||||||
16 |
Does the scan tool indicate DTC P0443 failed this ign? | -- | System OK |
