Test Description
WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers in the diagnostic procedure.
- 2
This step verifies that the condition is not intermittent. - 4
This step determines which set of fuel injectors the circuit condition is affecting. If DTC P2146 is set, then a condition exists on cylinders 1, 4, 6, or 7. If DTC P2149 is set, then a condition exists on cylinders 2, 3, 5, or 8. - 5
This step tests if a ground is constantly being applied to the fuel injectors. - 6
This step isolates which circuit is causing the condition. If the DMM displays OL when a multi-way connector is disconnected, test the affected circuits for a short to ground. - 7
This step tests for an open circuit. If the DMM displays OL on all of the fuel injector circuits, the injector supply voltage circuit is open. - 8
This step tests for an open circuit. If the DMM displays OL on one of the fuel injector circuits, the fuel injector command circuit is open. - 9
This step tests for excessive resistance in a fuel injector circuit. - 10
This step is testing for a short between the injector supply voltage circuit and the fuel injector command circuit. If the resistance of the circuits is less than 0.3 ohms, test for a short between the circuits. If a short cannot be found, the fuel injector may be the cause of the condition. The normal fuel injector resistance is between 0.3-0.4 ohms. - 11
This step tests for a short to voltage on a fuel injector circuit. If the DMM displays battery voltage a short to voltage is the cause of the condition. - 12
This step isolates which circuit is causing the condition. If the DMM display changes to 0 volts when a multi-way connector is disconnected, test the disconnected circuits for a short to voltage. - 13
This step tests if a ground is constantly being applied to the fuel injectors. - 14
This step isolates which circuit is causing the condition. If the DMM displays OL when a multi-way connector is disconnected, test the affected circuits for a short to ground. - 15
This step tests for an open circuit. If the DMM displays OL on all of the fuel injector circuits, the injector supply voltage circuit is open. - 16
This step tests for an open circuit. If the DMM displays OL on one of the fuel injector circuits, the fuel injector command circuit is open. - 17
This step tests for excessive resistance in a fuel injector circuit. - 18
This step is testing for a short between the injector supply circuit and the fuel injector command circuit. If the resistance of the circuits is less than 0.3 ohms, test for a short between the circuits. If a short cannot be found, the fuel injector may be the cause of the condition. The normal fuel injector resistance is between 0.3-0.4 ohms. - 19
This step tests for a short to voltage on a fuel injector circuit. If the DMM displays battery voltage a short to voltage is the cause of the condition. - 20
This step isolates which circuit is causing the condition. If the DMM display changes to 0 volts when a multi-way connector is disconnected, test the disconnected circuits for a short to voltage.