DTC Troubleshooting: P0778 (23-2)

DTC P0778:  Problem in A/T Clutch Pressure Control Solenoid Valve B Circuit

NOTE: Record all freeze data before you troubleshoot.

1.Disconnect the A/T clutch pressure control solenoid valve B connector.

2.Measure A/T clutch pressure control solenoid valve B resistance at the solenoid valve connector terminals.

 

Is there about 5 W?


YES - Go to 3.


NO - Replace the  A/T clutch pressure control solenoid valve B.n

3.Disconnect the battery negative terminal.

4.Disconnect PCM connectors B (24P) and C (22P).

5.Check for continuity between PCM connector terminals B16 and body ground, and between C8 and body ground.

 

Is there continuity?


YES - Repair short to ground in the wires between PCM connector terminals B16 and the  A/T clutch pressure control solenoid valve B, and between C8 and the solenoid valve B.n


NO - Go to 6.

6.Connect the A/T clutch pressure control solenoid valve B connector.

7.Measure the resistance between PCM connector terminals B16 and C8.

 

Is there about 5 W?


YES - Go to 8.


NO - Repair loose terminal or open in the wires between PCM connector terminals B16 and the  A/T clutch pressure control solenoid valve B, and between C8 and the solenoid valve B.n

8.Disconnect PCM connector A (31P).

9.Check for continuity between PCM connector terminals A23 and body ground, and between A24 and body ground.

 

Is there continuity?


YES - Check for loose terminal fit in the PCM connectors. If necessary, substitute a known-good  PCM and recheck.n


NO - Repair open in the wires between PCM connector terminals A23 and ground ( G101), and between A24 and ground (G101), and repair poor ground (G101).n