Circuit Description
The PCM controls the fuel injectors by using an ignition feed driver and ground circuit within the PCM. The driver has the ability to detect an electrical malfunction in the ignition feed or ground circuit. If an electrical malfunction occurs in the fuel injector circuit for engine cylinder #4, the ignition feed driver signals the PCM to set DTC P0204.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
| • | The PCM detects an electrical malfunction on the injector circuit for engine cylinder #4. |
| • | The condition is 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
The misfire history counter may be useful in determining which injector circuit is malfunctioning. If DTC P0300 was set, look at the Misfire History display for each cylinder. The largest value stored in the misfire history counters will indicate the location of the malfunctioning injector circuit or injector.
Check for the following conditions:
| • | Poor connection at the PCM or fuel injector. |
| Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. |
| • | Damaged harness. |
| Inspect the wiring harness for damage. |
If the DTC cannot be duplicated and is determined to be intermittent, reviewing the Failure Records can be useful in determining when the DTC was last set. Also refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
-
Checks for malfunctioning fuel injector control circuit or ignition feed wiring.
-
Checks for a malfunction in the fuel injector ignition feed circuit.
-
Checks for a short to ground in the injector control circuit.
-
Checks for an open in the fuel injector 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 | Value(s) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||||||
2 | With the engine idling, monitor Specific DTC info for DTC P0204 on the scan tool. Does the scan tool indicate DTC P0204 failed this ignition? | -- | ||||||
3 |
Does the scan tool indicate DTC P0204 failed this ignition? | -- | Go to Diagnostic Aids | |||||
Does the cylinder #4 fuel injector control circuit measure near the specified value? | B+ | |||||||
5 | Test the fuel injectors. Refer to Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Between 10-35 Degrees C (50-95 Degrees F) or Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Outside 10-35 Degrees C (50-95 Degrees F) . Did you find a faulty injector? | -- | ||||||
6 |
Does the cylinder #4 fuel injector control circuit measure near the specified value? | 0V | ||||||
7 |
Did you find and correct the condition? | -- | ||||||
8 |
Did you find and correct the condition? | -- | ||||||
Does the ignition feed circuit measure near the specified value? | B+ | |||||||
Probe the cylinder #4 fuel injector control circuit at the cylinder #4 fuel injector harness connector with a test lamp connected to B+. Does the test lamp illuminate? | -- | |||||||
Does the test lamp illuminate? | -- | |||||||
12 |
Did you find and correct the condition? | -- | ||||||
13 | Locate and repair open in the cylinder #4 fuel injector control circuit. Refer to Wiring Repairs in wiring systems. Did you find and correct the condition? | -- | -- | |||||
14 | Locate and repair open or short to ground in the cylinder #4 fuel injector ignition feed circuit. Refer to Wiring Repairs in wiring systems. Did you find and correct the condition? | -- | -- | |||||
15 | Locate and repair short to ground in the cylinder #4 fuel injector control circuit. Refer to Wiring Repairs in wiring systems. Did you find and correct the condition? | -- | -- | |||||
16 | Locate and repair short to voltage in the cylinder #4 fuel injector control circuit. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | -- | |||||
17 | Replace malfunctioning fuel injector(s). Refer to Fuel Injector Replacement . Did you complete the replacement? | -- | -- | |||||
|
Important:: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Did you complete the replacement? | -- | -- | ||||||
19 |
Does the DTC reset? | -- | System OK |
