The engine light on my 96 Maxima turned on a few days ago. Followed the ECU code testing procedure and found “1106 A/T fourth gear signal fault”. I have turned the engine light off but I am sure my Maxima is having a problem and I am not sure how to fix it. Does the “A/T fourth gear signal fault” imply the transmission has to be replaced? Thanks for your advices.

 

1103 1104 1105 1106
Since DTCs 1103 to 1106 deal with the transmission, there is info on the 1106 DTC. Everywhere you see "4th gear", simply substitute "1st gear".

Diagnostic Trouble Code 1106 means "Automatic Transmission 4th gear malfunction."

This malfunction is detected when the automatic transmission does not shift into fourth gear or the torque converter clutch does not lock up as instructed by the Transmission Control Unit. The factory service manual lists these possible
causes...

- Shift solenoid A
- Shift solenoid B
- Overrun clutch solenoid valve
- Line pressure solenoid valve
- Each clutch
- Hydraulic control circuit
- Torque converter clutch solenoid valve

You can do some troubleshooting without opening the automatic transmission. Find the harnesses which emanate from the transaxle. One of them terminates in a brown plastic connector with eight pins. This is connector F42, located (approximately) above the transaxle case and below the black plastic engine air intake ductwork. With the engine off, disconnect F42. You want to measure the transmission side of F42. Hold the connector such that the plastic latch is at the top. You should now see two rows of four terminals. These are numbered (top row, left to right) 1 - 4, and (bottom row, left to right) 5 - 8. Make resistance measurements between a clean ground and the following terminals:

#1, Shift solenoid B, 20 - 40 ohms.
#2, Shift solenoid A, 20 - 40 ohms.
#3, Overrun clutch solenoid valve, 20 - 40 ohms.
#4, Line pressure solenoid valve, 2.5 - 5 ohms.
#5, Torque converter clutch solenoid valve, 10 - 20 ohms.

There is also a "bench test" procedure for testing these solenoids with a 12 volt supply such as a car battery. However, this requires removal of the shift solenoid valve assembly. I don't know if you want to get involved with that.

 

Thanks for the reply. So I have to fix the part if the measured resistance does not appear correctly? Anyone knows how easy to fix it (DIY) and cost? Thanks in advance.

 

my friend had that.. he just took it to a tranny shop.. of course they just told him he needed to get a new one