Refer to Engine Controls Schematics .
Circuit Description
Ignition voltage is supplied directly to the malfunction indicator lamp (MIL). The PCM controls the lamp by grounding the control circuit via an internal switch called a driver. The primary function of the driver is to supply the ground for the component being controlled. Each driver has a fault line which is monitored by the PCM. When the PCM is commanding a component on, the voltage of the control circuit should be low (near 0 volts). When the PCM is commanding the control circuit to a component off, the voltage potential of the circuit should be high (near battery voltage). If the fault detection circuit senses a voltage other than what is expected, the fault line status will change causing the DTC to set.
Conditions for Running the DTC
| • | The ignition is ON. |
| • | The system voltage is between 9.0 and 18.0 volts. |
Conditions for Setting the DTC
| • | An improper voltage level has been detected on the MIL control circuit. |
| • | The above condition present for at least 30 seconds. |
Action Taken When the DTC Sets
| • | The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed. |
| • | The PCM will store conditions which were present when the DTC set as Freeze Frame/Failure Records data. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic has run and passed. |
| • | The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using a scan tool. |
Diagnostic Aids
Inspect for the following conditions:
Many situations may lead to an intermittent condition. Perform each inspection or test as directed.
Important: : Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.
| • | Loose terminal connection |
| - | Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair. |
| - | Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair. |
| • | Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair. |
| • | Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair. |
If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.
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.
-
Tests 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 replaced, the new PCM must be programmed.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
Does the voltage measure at or near the specified value? | B+ | |||
3 | Probe the MIL control circuit using a test lamp that is connected to ground. Does test lamp illuminate? | -- | ||
Does the voltage measure at or near the specified value? | 0.0V | |||
5 | Repair the short to voltage in the MIL control circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
6 | Inspect the ignition feed fuse for the IP Cluster indicators. Is the fuse open? | -- | ||
7 |
Did you find and correct the condition? | -- | Go to Diagnostic System Check - Instrument Cluster in Instrument Panel, Console and Gauges | |
8 |
Does the voltage measure at or near the specified value? | B+ | ||
9 | Test the MIL control circuit for an open or a short to ground. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
10 | Inspect the MIL control circuit and the instrument panel indicators ignition feed circuit for a poor connection at the instrument panel and the PCM. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Diagnostic System Check - Instrument Cluster in Instrument Panel, Console and Gauges | |
11 |
Does the test lamp flash ON and OFF with each command? | -- | Go to Diagnostic Aids | |
12 | Inspect the MIL control circuit for a faulty connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
13 | Repair the open in the ignition feed circuit to the IP Cluster indicators. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
|
Important:: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Did you complete the replacement? | -- | -- | ||
15 |
Does the DTC reset? | -- | System OK |
