Figure 42. Short Between Wires and to Ground

WTEC III ELECTRONIC CONTROLS TROUBLESHOOTING MANUAL

WIRE CHECK PROCEDURES

(2) On the opposite end of the harness, check the continuity of the jumpered pair. No continuity in a

jumpered pair circuit (infinite resistance reading) indicates an open in the wire being tested.

Locate and repair the damaged portion of the wire.

b. If the continuity check is good (02 Ohms resistance), remove the jumpers. Check the harness for

shorts between wires and shorts-to-ground by performing the following (refer to Figure 42):

(1) At the ECU end of the harness, touch one VOM probe to one wire of the circuit being tested

and touch the other probe to each terminal in the same connector, then touch the probe to chas-

sis ground and to the transmission main housing. Do this for both wires in the circuit being

tested.

(2) If at any time the VOM shows zero to low resistance, or the meter's continuity beeper sounds,

there is a short between the two points being probed -- wire-to-wire or wire-to-ground. Isolate

and repair the short.

TRANSMISSION CONNECTOR

WIRING HARNESS

ECU

"T" CONNECTOR

Wires shorted

together

Shorted to

ground on

metal frame

rail

Ground

to metal

frame rail

VOLT/OHM-

( ETER

VOM)

0 OHMS

Harness has been chafed and one or more

Two wires have frayed and are shorted

wires are shorted-to-ground. VOM continuity

together. Continuity beeper of VOM will

beeper will sound, or reading will go to zero

sound, or reading will go to zero Ohms

Ohms when meter is probing between this wire

when these two wires are probed with

and chassis ground.

the VOM.

V03375

Figure 42. Short Between Wires and to Ground

42.

CHECKING AT TRANSMISSION CONNECTOR AND THE INTERNAL HARNESS

FOR OPENS, SHORTS BETWEEN WIRES, AND SHORTS-TO-GROUND

Disconnect the external wiring harness from the transmission.

Inspect the connectors. Any terminals which are corroded or dirty must be thoroughly cleaned.

If the connectors are clean and connected correctly, determine which wires in the harness to test. Use

the diagnostic code system schematic to locate the wire terminals. For this example, Code 41 12 indi-

cates an open or short-to-ground in solenoid "A" circuit -- wires 102-T1 and 120-T4 (refer to Figure

43 and 44).

0021 0030