SAAB WIS ONLINE

DTC P0748 PRESSURE CONTROL SOLENOID “A” ELECTRICAL

DTC P0748 PRESSURE CONTROL SOLENOID “A” ELECTRICAL

DIAGNOSIS:

The output signal circuit of line pressure linear solenoid is open or shorted.

TROUBLE SYMPTOM:

Excessive shift shock.

WIRING DIAGRAM:


CHECK HARNESS CONNECTOR BETWEEN TCM AND TRANSMISSION.

Turn the ignition switch to OFF.

Disconnect the connector from transmission and TCM.

Measure the resistance of harness between TCM and transmission connector.

Connector & terminal

(B56) No. 19 — (B11) No. 2:

(B56) No. 20 — (B11) No. 1:

Is the resistance less than 1 Ω?

Yes


No

Repair the open circuit in harness between TCM and transmission connector.


CHECK HARNESS CONNECTOR BETWEEN TCM AND CHASSIS GROUND.

Measure the resistance of harness between TCM and chassis ground.

Connector & terminal

(B56) No. 19 — Chassis ground:

(B56) No. 20 — Chassis ground:

Is the resistance more than 1 MΩ?

Yes


No

Repair the short circuit in harness between TCM and transmission connector.


CHECK LINE PRESSURE LINEAR SOLENOID.

Measure the resistance between transmission connector receptacle’s terminals.

Connector & terminal

(T4) No. 1 — No. 2:

Is the resistance 4 — 8 Ω?

Yes


No


CHECK LINE PRESSURE LINEAR SOLENOID (IN TRANSMISSION).

Remove the transmission connector from bracket.

Drain the ATF.

Important

Do not drain the ATF until it cools down.


Remove the oil pan, and disconnect connector from line pressure linear solenoid.

Measure the resistance between line pressure linear solenoid connector and transmission ground.

Connector & terminal

(AT11) No. 2 — No. 4:

Is the resistance 4 — 8 Ω?

Yes


No

Replace the control valve body.


CHECK HARNESS CONNECTOR BETWEEN TRANSMISSION AND LINE PRESSURE LINEAR SOLENOID.

Measure the resistance of harness between line pressure linear solenoid and transmission connector.

Connector & terminal

(T4) No. 2 — (AT11) No. 4:

(T4) No. 1 — (AT11) No. 2:

Is the resistance less than 1 Ω?

Yes


No

Repair the open circuit in harness between line pressure linear solenoid and transmission connector.


CHECK HARNESS CONNECTOR BETWEEN TRANSMISSION AND LINE PRESSURE LINEAR SOLENOID.

Measure the resistance of harness between transmission connector and transmission ground.

Connector & terminal

(T4) No. 1 — Transmission ground:

(T4) No. 2 — Transmission ground:

Is the resistance more than 1 MΩ?

Yes

Even if the POWER indicator blinks, the circuit has returned to a normal condition at this time. A temporary poor contact of the connector or harness may be the cause. Repair the harness or connector in line pressure linear solenoid and transmission.


No

Repair the short circuit in harness between line pressure linear solenoid and transmission connector.