ALDL Connector Information

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The following is a listing of the ALDL connector terminal locations and the circuits to which they are connected .

TERMINAL A

GROUND CIRCUIT

# 450

Connected to common ground circuit from ECM terminals A-12, D-1 D-3, D-6, and D-10 (refer  System Ground and Table 4, Ground Connections) which are, in turn, connected to a secure engine ground.

TERMINAL B

DIAGNOSTIC CIRCUIT

# 451

Connected to ECM Terminal A-9.

TERMINAL C

AIR SOLENOID CIRCUIT

# 436

Connected to ECM Terminal A-2 (See A-2) if utilising the AIR system.

TERMINAL D

NOT USED

Used with Service Engine Soon lamp. Not required.

TERMINAL E

SERIAL DATA CIRCUIT

#461

Connected to ECM Terminal A-8.

TERMINAL F

TCC CIRCUIT

#422

Connected to ECM Terminal A-7 (See A-7) if utilising an ECM controlled TCC system

TERMINAL G

FUEL PUMP TEST CIRCUIT

#490

Connected to fuel pump relay Terminal D (Design 1) or Terminal E (Design 2).

TERMINAL M

SERIAL DATA CIRCUIT

#461

Also connected to ECM Terminal A-8 (See A-8), in some applications.

Because of the use of different intermediate plugs and harnesses between the ECM and the ALDL connector on different make and year vehicles, the colour codes on the wires attached to the ALDL terminals will not always match the codes on the appropriate wires from the ECM. Double check the connections to ensure the proper circuits go to the proper terminals.