Car Info:
1993 Honda Accord EX Coupe
Engine Type: 2.2L L4 SOHC 16V
Transmission: 4-Speed Automatic Overdrive

It has been running pretty good until Saturday.

I am hoping someone can help. My husband is stumped, we called the dealer, they have no idea. We cannot afford a trip to the dealer or anyone else. My husband and a friend know how to repair cars, just this has everyone scratching there head.

The car will not shift, seems to be in "limp" mode and the temp gauge was reading hot. The car is not running hot. It goes from cold to hot even when first started. We changed the sensor for the fan, temp sensor for the gauge and the one for the ECU, we reset the computer, the temp gauge works when manually tested. It is still reading hot when you turn the ignition key on. We checked all the grounds and they were fine.

We have been told to change the instrument cluster. I am not sure this is needed because the gauge worked when checked manually. If so does anyone know how to get the thing out.

We are stuck, not sure what else to do. HELP!!!! Please, lol.

 

If, as you say, you replaced the temp sending unit (the one the computer reads) I would start testing your computer.

It is possible your computer has had it.

 

You said the car is not starting. When you turn the key to start the car what happens?

Remove the 7.5 amp backup/radio in the engine bay fuse box for a minute. Then try restarting the car.

The temperature gauge will not cause the car to not start.

 

PAhonda, the car is starting and basically running fine. When we turn the key the car starts with no problem, runs fine. Just when you start it the temp gauge goes to hot. We have checked everything that would normally cause an engine to be hot, it is hot even after setting for a full day and night. No problems starting either. Until Saturday the car was running great. The fuses have been checked.

Silver6gen, the computer is fine, has been checked.

Let me reiterate this: The car starts, runs great. When you start the car the temp gauge goes straight to hot. It can be driven but has gone into limp mode.. the car will not shift over 3rd gear. Honda has told us it is going into limp mode because the ECU thinks the car is overheating even when it is not. The engine temp has been tested and even though the gauge says hot the engine is not.

 

How your car reverts to limp mode 101.

Malfunction is sensed by engine management sensor ->

relayed through harness to ECU – ECU logs trouble codes and determines if trouble codes pose a threat to the life span of the engine

In this case throws engine into Limp Mode.

There is no CEL? I know this is an OBD 1 but it sure seems like this would register, although it’s not too surprising when you understand how great OBD 1 is.


So if you computer truly is “fine” then I would go back to the sensor. Check all the wiring with a multi meter to ensure that you don’t have a short. This sounds eerily similar to a lost ground somewhere. Check the ground points for your engine and transmission as well.

 

There is an important ground on the thermostat housing that you should unbolt. Clean the bolt and eyelet with some sandpaper. Then reattach.

The temperature gauge in your car should not cause the car to go into limp mode. This could be two different issues or a possible ground problem.

Has any work been done recently on your car?

 

Silver6gen, that is what we are doing today, checking for shorts. We have been talking with a Honda mechanic on this and they are the ones who told us about the limp mode. At first we thought the transmission was going bad but it is not, they are also the ones who checked the ECU and changed the sensors. It ran fine for a couple of miles after then back to the issue. We just cannot afford another trip to the dealer, can anyone, lol.

PAhonda, we will be checking this also.

Thank you for the help and info. I will let you know the outcome of today.

 

I forgot, there has been no work done except for when this issue started.

 

well gota get ready 4 work keep us posted!!!an to ur husband there are no problems only solutions!good luck finding urs!process of elimination

 

On your generation Accord, only certain things can cause the ECU to put the car in limp mode.

Some of the symptoms you describe point to input from the TW sensor (also known as the ECT sensor) circuit.

Sounds like you may already have changed the TW sensor. This would start pointing to a problem with the thermostat or a faulty replacement TW sensor or circuit from the TW sensor to TCU. There is also the possibility it is the TCU. Your model year Accord has separate ECU and TCU (Transmission Control Unit); both located under the passenger side footwell. Your model year Accord was known for problems with the TCU such as blown capacitors and/or burnt resistors in the TCU. You can pull out the TCU and open it up to inspect.

So to recap: thermostat, TW sensor, TCU, and wiring would be the things to focus on.

See attached pics. (one of the attached picture looks like a thin black line; but, has info. in it) and links.

Honda Forum : Honda and Acura Car Forums - View Single Post - limp mode, limp home mode etc...

CB7Tuner Forums - View Single Post - Automatic Transmission FAQs