Test Notes

WARNING: RED-STRIPED WIRES CARRY 115V DC. SEVERE ELECTRICAL SHOCK MAY BE RECEIVED. DO NOT PIERCE.

CAUTION: Do not pierce engine electrical wires or damage to the harness may occur.

Injector Driver Circuit:

OUTPUT FUNCTIONS

High Side Drive Outputs (Right and Left Bank) - The high side driver output function is to distribute energy to the proper bank based on Cylinder Identification (CID) and provide regulated current to the unit injectors, based on Fuel Delivery Control Signal (FDCS) from the Injector Diver Module (IDM) internal 115V supply. The injection timing and duration is commanded by the Powertrain Control Module (PCM) in the FDCS signal.

Low Side Drive Outputs - The low side drive outputs control the sequencing (firing order) of the engine based on the CID and FDCS inputs.

Injector Driver Connections:

DETECTION/MANAGEMENT
The IDM is capable of detecting individual injector open and shorts to either ground or battery while the engine is running. It is also capable of detecting right or left bank high side opens or shorts to ground. A special on-demand Buzz test will also allow the operator to enable all injector solenoids while the engine is off to verify circuit operation. IDM detected diagnostic trouble codes will not be transmitted if the Electronic Feedback (EF) line is not functioning; however, the engine will function normally.

If a low side short to ground condition is determined by the IDM, this condition will be transmitted to the PCM via the EF signal. The PCM will enable the CHECK ENGINE light and command minimum fuel to the affected bank.

Electrical Harness & Connector Checks:

Engine Harness Connector Check To Chassis Ground

Electrical Harness & Connector Checks:

Valve Cover Gasket Connector To Chassis Ground
Check with pigtail connector installed on gasket connector.

Electrical Harness & Connector Checks:

Under Valve Cover Harness And Injector Solenoid Resistance Checks
Check with pigtail connector installed on gasket connector.

Part 1 Of 2:

Part 2 Of 2:

Engine Harness To IDM Connector Checks

NOTE: After removing connectors always check for damaged pins, corrosion, loose terminals, etc..