Torque Converter Clutch (TCC) Check

Fig. 22 Transmission wiring circuit. 1984:

Fig. 23 Transmission wiring circuit. 1985:

Do not use this procedure if any of the following codes are stored hard: 21, 22, 24, 28, 29, 33, 35 or 36.
1. Turn ignition on and connect a test lamp between ALDL diagnostic connector pin F and ground.
2. If test lamp lights, proceed as follows:
a. Enter diagnostics and display Code .9.6. If test light remains lit, proceed to step 2b. If test lamp now flashes in three second intervals, the TCC electrical system is operating satisfactorily.
b. Disconnect transmission electrical connector and measure resistance between pins A and D on transmission side of connector.
c. If resistance is less than 15 ohms, repair short circuit in transmission and ensure ECM was not damaged.
d. If resistance is greater than 15 ohms, check circuit 422, Figs. 22 and 23, for an open. If circuit is satisfactory, fault is in ECM or ECM connector. Repair or replace as necessary.
3. If test lamp does not light, proceed as follows:
a. With ignition on and brakes released, alternately connect test lamp between both sides of TCC brake and ground.
b. If test lamp lights on one side of switch only, check adjustment of TCC brake and adjust or replace switch as necessary.
c. If test lamp does not light on either side of switch, check condition of GA-TRANS fuse. If fuse is not blown, repair open in circuit 39 or 3, Figs. 22 and 23. If fuse is blown, repair ground in circuits fed by fuse, then replace the fuse.
d. If test lamp lights on both sides of switch, disconnect transmission electrical connector and connect test lamp between harness connector pin A and ground. If test lamp lights, proceed to step 3e. If test lamp does not light, repair open in circuit 420.
e. Connect test lamp between harness connector pins A and D. If test lamp lights, proceed to step 3f. If test lamp does not light, proceed to step 3g.
f. Disconnect red ECM connector (P-2). If test lamp remains lit, repair short to ground in circuit 422. If test lamp goes out, fault is in ECM or ECM connector. Repair or replace as necessary.
g. Ground ALDL connector pin F. If test lamp remains off, repair open in circuit 422. If test lamp now lights, check for an open or short to ground in transmission. If no open or short is found, check for improper mating of transmission electrical connectors and correct as necessary.