Table A1-5 Fuel Injector Circuit Check (Engine No-Start)

Fuel Injector Circuit Check (Engine No-Start):

Fuel Injector Circuit Check (Engine No-Start)(continued):

Electrical Schematic:

Circuit Description

When the solenoid coil of the fuel injector is energized by the Powertrain Control Module (PCM), it will activate the plunger and pressurized fuel will be injected into the Throttle Body Fuel Injection (TBI) unit. The fuel pump will operate as long as the engine is cranking, and the PCM is receiving ignition reference pulses. If the PCM does not receive any reference pulses, the fuel pump will stop after 2 seconds.


Diagnostic Aids

There may be fuel spray at the fuel injector, but it may not be enough to start the engine. If both the fuel injector and the circuit are OK, the fuel injector nozzle may be partly blocked.

An intermittent malfunction may be caused by a poor connection, rubbed through wire insulation, or a wire broken inside the insulation. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal-to-wire connections before component replacement.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.


1. The Powertrain OBD System Check prompts the technician to complete some basic checks and store the freeze frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.

2. Checks to see if the PCM is controlling the fuel injector signals.

3. Checks the fuel injector for correct resistance.

5. Checks for voltage at fuel injector.

6. Checks for an open or short to ground in fuel injector control circuit, a faulty PCM or for a faulty fuel injector.

13. Checks for an open in YEL wire, an open in Ignition feed circuit or for a faulty fuel injector resistor.