I have been through quite a few of these post to try to find the problem with my 92 honda. The D4 light starting staying on several months ago. I would reset with either unhooking battery or by taking out the ECU fuse. It eventually would not reset and all the searching I did basically led me to the TCM. I took mine out and did have burnt stuff. I had these fixed and still same thing. I then just went and bought a remaned TCM. The D4 light continues to stay on. I have checked for the click in both of the transmission solenoids and they seemed to be ok. I don't know what to check now???? I have to put the key in the key slot to get it out of park now. Any ideas? Thanks for any help

 

clean ur auto shifter. under the shifter there is a metal piece with grooves for gear selection.

check for trans codes with jumper or scan tool

 

Two wire blue connector over by the passenger kick panel, jumper it, turn ignition to II(ON), retrieve codes from D4 lamp blinking. Post here.

 

You need to clarify what car you have. yesterday you posted the same problem in the civic forum.

 

I have tried to get codes from blue plug at kick panel but nothing on dash blinks.

 

If your CEL or D4 lamp do not illuminate when the key is turned to II(ON) when you first turn the key then the lamps are burnt out and need to be replaced so you can see what the codes are.

 

The CEL and D4 lights come on when key is in on position. When I jump to get codes no lights anywhere on dash blink.

 

Use a different wire or back probe the connection.
Even if there are no codes the CEL should still come on.

 

The CEL and all other lights come on when the switched is turned on but when I do the wire jump the D4 nor the CEL lights blink any codes. Is it possible the console shifter switch is bad causing D4? I think I read somewhere that if shifter switch is bad then you will not here a click @ console when you depress the break. I have replaced and or checked everything that I have researched to check. Any ideas?????

 

Back trace the two wire blue connectors wire harness, verify it is still connected to the main harness.

Next step would be to verify all the fuses in the passenger compartment and underhood are not blown.

Non functional interlock could be from a blown fuse, faulty brake switch, ICU issues, or fault with the interlock solenoid itself.

 

I have check the blue wires and everything looks ok. I have checked all fuses inside car and under hood and all are ok. I had previously checked the lock up solenoid and it clicked so I assume this is ok also.

I am not sure what the ICU is???????

 

The D4 light staying on and being unable to shift out of Park may be all related to a TCM issue. Can be an issue with wiring for power or ground to TCM or still an issue with TCM itself.

1. Unable to shift out of PARK:
On your TCM, the brake switch signal has to go through the TCM to the interlock control system. If the brake switch signal doesn't go through the TCM, the shift lock relay (which is inside the interlock control unit) won't energize. From the brake switch, there is a Grn/Wht wire (brake switch input) that eventually goes to a original TCM harness connector. The shift lock circuit control signal exit the TCM via a Wht/Grn wire to the interlock control unit. There are two harness connectors to the TCM; the Wht/Grn wire is at terminal number 22 of the 26-P connector. If you backprobe the Wht/Grn wire there should be voltage with the brake pedal pressed.

This is how the shift position interlock works:
When you push the brake pedal, battery voltage is sent through a Grn/Wht wire from the brake switch to the TCM. If, at the same time, you do not push the accelerator pedal, a low voltage signal is sent from the TPS through a RED/BLK wire to the TCM. The TCM then applies voltage through a WHT/GGRN wire to the shift lock circuit in the interlock control unit. Ground is provided to the shift lock solenoid through the A/T gear position switch. The solenoid then energizes, releasing the A/T gear lever. The solenoid is then energized allowing the shift lever to be moved from the PARK position.

2. D4 light still on with remanufactured TCM:
You may want to make sure the remanufactured TCM circuit board and components also look okay.

Check under-hood Fuse No. 24 (7.5A) and No. 25 (20A).

Check under-dash Fuse No. 2 (15A).

Check your ground wires attached to ground G101 (located at the thermostat housing).

Check ground wire at ground G401 (located behind left kick panel, near hood release lever).