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 #3, the ignition feed driver signals the PCM to set DTC P0203.
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 #3 for longer than 30 seconds. |
| • | 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 and Failure Records data. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been 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 the 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 Hist # 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 wore connection. |
| • | Damaged harness. |
| Inspect the wiring harness for damage. |
Reviewing the Freeze Frame/Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.
Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
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Tests for malfunctioning fuel injector control circuit or ignition feed wiring.
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Tests for a malfunction in the fuel injector ignition feed circuit.
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tests for a short to ground in the injector control circuit.
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Tests for an open in the fuel injector control circuit.
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This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM isreplaced, the new PCM must be programmed.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
2 | With a scan tool and the engine idling, observe Specific DTC info for this DTC. Does the scan tool indicate this DTC failed this ignition? | -- | ||
3 |
Does the scan tool indicate this DTC failed this ignition? | -- | Go to Diagnostic Aids | |
Does the voltage measure at or 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) . Are all injectors OK? | -- | ||
6 |
Does the voltage measure at or near the specified value? | 0V | ||
7 | Test for the following conditions:
Refer to Wiring Repairs . Did you find and correct the condition? | -- | ||
8 |
Did you find and correct the condition? | -- | ||
Does the voltage measure at or near the specified value? | B+ | |||
Probe the injector control circuit using a J 35616-200 Test Lamp that is connected to B+. Does the test lamp illuminate? | -- | |||
Does the test lamp illuminate? | -- | |||
12 | Inspect for poor connections at the injector. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs . Did you find and correct the condition? | -- | ||
13 | Locate and repair open in the injector control circuit. Refer to Wiring Repairs . Did you complete the repair? | -- | -- | |
14 | Locate and repair open in the injector ignition feed circuit. Refer to Wiring Repairs . Did you complete the repair? | -- | -- | |
15 | Locate and repair short to ground in the injector control circuit. Refer to Wiring Repairs . Did you complete the repair? | -- | -- | |
16 | Locate and repair short to voltage in the injector control circuit. Refer to Wiring Repairs . Did you complete the repair? | -- | -- | |
17 | Replace malfunctioning fuel injector(s). Refer to Fuel Injector Replacement . Did you complete the replacement? | -- | -- | |
|
Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Did you complete the replacement? | -- | -- | ||
19 |
Does the DTC reset? | -- | System OK |
