DTC Troubleshooting

DTC Troubleshooting: P0990 (176-4)

DTC P0990:

Open in Transmission Fluid Pressure Switch E (6th Clutch) Circuit, or Transmission Fluid Pressure Switch E (6th Clutch) Stuck OFF

NOTE:

- Before you troubleshoot, record all freeze data and any on-board snapshot with the HDS, and review the General Troubleshooting Information How to Troubleshoot the A/T System.
- If DTC P0990 is stored in the PCM, the transmission does not shift to any gear other than 3rd or 6th gear because of the fail-safe function.

1. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

2. Clear the DTC with the HDS.

3. Raise the vehicle on a lift, make sure it is securely supported, and allow all wheels to rotate freely.

4. Start the engine, disable the VSA by pressing the VSA OFF button. Run the vehicle with the sequential sportshift mode in 6th gear. Check the 6th Pressure Switch signal with the HDS in the A/T Data List. Slow down, and stop the wheels.

Is the 6th Pressure Switch ON in 6th gear?

YES -

Intermittent failure, the system is OK at this time. Check for poor connections and loose terminals between transmission fluid pressure switch E (6th clutch) and the PCM.

NO -

Go to step 5.

5. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

6. Disconnect the transmission fluid pressure switch E (6th clutch) connector.

7. Connect a jumper wire between the transmission fluid pressure switch E (6th clutch) connector terminal and body ground.





8. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

9. Check the 6th Pressure Switch signal with the HDS in the A/T Data List.

Is the 6th Pressure Switch ON?

YES -

Replace transmission fluid pressure switch E (6th clutch) Transmission Fluid Pressure Switch E (6th Clutch) Replacement.

NO -

Go to step 10.

10. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

11. Remove the jumper wire.

12. Jump the SCS line with the HDS.

13. Disconnect PCM connector C (49P).

14. Check for continuity between PCM connector terminal C31 and the transmission fluid pressure switch E (6th clutch) connector terminal.





Is there continuity?

YES -

Replace the PCM Service and Repair.

NO -

Repair an open in the wire between PCM connector terminal C31 and the transmission fluid pressure switch E (6th clutch) connector terminal.