P0201-CYLINDER 1-INJECTOR CIRCUIT CURRENT DECREASE
For a complete wiring diagram Refer to Section 8W
| Possible Causes |
| ENGINE CONTROL MODULE |
| INTERMITTENT CONDITION |
| FUEL INJECTOR CONTROL CIRCUIT SHORTED TO VOLTAGE |
| FUEL INJECTOR CONTROL CIRCUIT SHORTED TO GROUND |
| FUEL INJECTOR CIRCUITS SHORTED TOGETHER |
| FUEL INJECTOR CONTROL CIRCUIT OPEN |
| FUEL INJECTOR |
Diagnostic Test
1. VERIFY ACTIVE DTCNOTE: If the ECM detects and stores a DTC, the ECM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the scan tool at the same time the DTC is displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.
Turn the ignition on.
With the scan tool, erase the ECM DTCs.
Attempt to start the engine and test drive the vehicle.
With the scan tool, read the ECM DTCs.
Did this DTC set again?
Yes
- Go To2
No
- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
2. CHECKING FOR OTHER DTCS
NOTE: An open ASD power supply to the ECM will cause multiple DTC's including this DTC to set.
NOTE: Check the ECM for other DTC's. If other DTC's are set with this DTC refer to the symptom list and perform the CHECKING THE ECM POWER AND GROUND CIRCUITS test before continuing.
If the ECM power and ground circuits are functioning properly continue with this test.
Yes
- Go To3
3. FUEL INJECTOR CONTROL CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Disconnect all of the Cylinder Fuel Injector harness connectors.
Disconnect the ECM harness connectors.
Remove the ASD Relay from the PDC.
Connect a jumper wire between cavity 30 and cavity 87 of the ASD Relay connector.
Turn the ignition on.
Measure the voltage of each Fuel Injector High-Side Control circuit.
Measure the voltage of each Fuel Injector Low-Side Control circuit.
Is the voltage above 1.0 volt for any of the measurements?
Yes
- Repair the appropriate Fuel Injector Control circuit for a short to voltage.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
No
- Go To4
4. FUEL INJECTOR CONTROL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect all of the Fuel Injector harness connectors.
Measure the resistance between ground and each Fuel Injector High-Side Control circuits.
Measure the resistance between ground and each Fuel Injector Low-Side Control circuits.
Is the resistance below 1000 ohms for any of the measurements?
Yes
- Repair the Fuel Injector Control circuit for a short to ground.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
No
- Go To5
5. FUEL INJECTOR CIRCUITS SHORTED TOGETHER
Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect all of the Cylinder Fuel Injector harness connectors.
Measure the resistance between each of the Fuel Injector High-Side Control circuits and the Fuel Injector Low-Side Control circuits.
Is the resistance below 1000 ohms for any of the measurements?
Yes
- Repair the Fuel Injector circuits that measured below 1000 ohms for a short together.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
No
- Go To6
6. FUEL INJECTOR CONTROL CIRCUIT OPEN
Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect all of the Cylinder Fuel Injector harness connectors.
Measure the resistance of each Fuel Injector High-Side and Low-Side Control circuits between its respective injector harness connector and the ECM harness connector.
Is the resistance below 10.0 ohms for each measurement?
Yes
- Go To7
No
- Repair the appropriate Fuel Injector Control circuit for an open.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
7. CYLINDER FUEL INJECTOR
Turn the ignition off.
Replace the appropriate Cylinder Fuel Injector (as indicated by the DTC) in accordance with the Service Information.
With the scan tool, erase the ECM DTCs.
Test drive the vehicle.
With the scan tool, read the ECM DTCs.
Does the scan tool display this DTC?
Yes
- Replace and program the Engine Control Module in accordance with the Service Information.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
No
- The repair is complete.
- Perform the ECM Verification Test Ver. 1 (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).