Circuit Description
The Powertrain Control Module (PCM) has four fuel injector driver circuits, each of which controls a fuel injector. The PCM monitors the current in each driver circuit and is able to control the driver circuit. The current through each driver can rise to a peak of 1 amp in order to quickly open the fuel injectors and to hold the fuel injectors open. This is called saturated switch. If the current cannot reach 1 amp, a DTC is set. This DTC is also set if an fuel injector driver is shorted to voltage.
Conditions for Running the DTC
| • | The engine is running. |
| • | The battery voltage is more than 9 volts. |
Conditions for Setting the DTC
| • | The injector current is less than 1 amp. |
| Or |
| The injector current is continuously high. |
| • | The above conditions are met for 7 seconds. |
Action Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) illuminates. |
| • | The PCM records the operating conditions at the time when the diagnostic fails. This information stores in the Freeze Frame and Failure Records buffers. |
| • | A history DTC stores. |
| • | The coolant fan turns ON. |
Conditions for Clearing the MIL/DTC
| • | The MIL will turn OFF after three consecutive ignition cycles in which the diagnostic runs without a fault. |
| • | A history DTC will clear after 40 consecutive warm-up cycles without a fault. |
| • | Use a scan tool to clear the DTCs. |
Diagnostic Aids
A fuel injector driver circuit that is open or shorted to voltage will cause a DTC P0201-P0204 to set and will also cause a misfire due to an inoperative injector. A misfire DTC should also be set indicating which injector is inoperative.
Long term and short term fuel trims that are excessively high or low are a good indication that an fuel injector is malfunctioning. Use Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Between 10-35 Degrees C (50-95 Degrees F) to check for malfunctioning fuel injectors.
A poor electrical connection may be cleaned when disconnecting and reconnecting the electrical connector. If the malfunction is not present after the electrical connector is disconnected and reconnected, check the electrical terminal connection for the following conditions:
| • | Corrosion |
| • | Poor terminal tension |
Test Description
The numbers below refer to step numbers on the diagnostic table.
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This step tests the harness wiring and the PCM control of the fuel injector with the fuel injector test lamp. If the test lamp blinks, the PCM and the wiring to the fuel injector is OK. The Fuel Inj Coil Test - ECT Between 10-35 Degrees and Fuel Inj Coil Test - ECT Outside 10-35 Degrees diagnostics will determine if the fuel injectors are malfunctioning.
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The replacement PCM must be programmed and the Crankshaft Position System Variation Learn procedure must be performed.
Step | Action | Values | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||||||
2 | Attempt to start the engine. Does the engine start and run? | -- | ||||||
Does the fuel injector test lamp blink? | -- | Go 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) | ||||||
4 | Did the fuel injector test lamp stay on steady when cranking the engine? | -- | ||||||
5 |
Does the test lamp illuminate? | -- | ||||||
6 | Repair the short to ground in the Driver circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |||||
7 |
Does the test lamp illuminate? | -- | ||||||
8 |
Does the test lamp illuminate? | -- | ||||||
9 |
Did you complete the repair? | -- | -- | |||||
10 |
Did you find and correct the condition? | -- | ||||||
11 |
Did you complete the repair? | -- | ||||||
|
Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the repair? | -- | -- | ||||||
13 |
Does the DTC reset? | -- | System OK |
