UWMU

I have a 1998 Acura 2.3CL automatic with 80,000 miles. Yesterday I was on the freeway and the D4 light started flashing. Also the check engine light had previously been on from a rear O2 sensor which I never got around to replacing.

When I got off the freeway, the car was really slow to accelerate. When I shifed it from D4 to park, the transmission would clunk when going over Reverse or putting it into reverse. It shifted fine once I got to 10-15 mph and was fine once it was up to speed.

I took it to Autozone for them to read the codes it put out codes for both 02 sensors, and:

P1768 - Pressure control solenoid valve A circuit fault
P1753 - TCC solenoid valve circuit fault
P0753 - Shift solenoid A circuit fault

When I was driving back on the freeway, my lights (interior and exterior started to dim), the radio went out, the RPM and Speedo gauges were going crazy and then went to 0, and then the car eventually lost power and died on the side of the freeway.

Any suggestions? I looked at some other forums and some people said they had these codes and it was just a matter of changing a fuse, or the alternator. Please help!

Shadoh

iTrader: (1)

Hope someone here with more knowledge can help you out bro! But atleast it sounds like its pure electrical... Have you checked all of the fuses? Tested the alt? Idk what it could be but i'd start with the fuses while waiting for some more informed people :p

UWMU

I pulled a few fuses and didn't see any blown. Are there any in particular that I should check out?

Otherwise, I'm charging my battery in hopes that I can make it a few miles to Autozone to have them test the battery and alternator.

I'm just wondering if it's purely electrical, or what the deal with the transmission codes is. It seems like a weird coincidence that both the transmission and electrical would fail at the same time.

Shadoh

iTrader: (1)

Auto trannies are known to be shitty for the CL, as for the fuses idk i havent spent much time down there My guess would be anything remotley related to the ECU would be a good guess to check.

UWMU

I just had the battery and the alternator tested and the alternator is shot. So the plan right now is to replace that and see what that takes care of.

So my question now is whether there still might be transmission problems given that it is still slow in accelerating and shifts rough from park to reverse or from D4 into reverse.

Could it be that the transmission's solenoids aren't getting enough power since the alternator is shot?

UWMU

I replaced the alternator but it didn't take care of the transmission problems. If I shift the car manually, it's fine. It's just accelerating slow in D3 or D4 but it's fine once you get past 1st gear.

Would there be any relation bertween the transmission and the alternator going, or was this just a weird coincidence?

Nakamichi

When my starter was acting up, the car was throwing compression codes. This is why the diagnostic routine is to (1) get the code; (2) reset errors and see if it occurs again. Sometimes it is just a fluke due to other problems.

If you are still getting transmissions error codes, you may want to look into to it more.

UWMU

Problem solved: ECU fuse was blown.

So I was able to take out the new alternator and put the old one back in again. The transmission shifts fine again and the D4 light stopped flashing. It all makes sense in retrospect, but it goes to show why you start with the small things first before ordering up a whole new transmission.

This exposed one huge design flaw: when the ECU fuse goes, it takes the battery light with it. Had I seen the battery light on, I wouldn't have driven it, and wouldn't have ended up on the side of the expressway with a $250 towing bill.

It seems pretty absurd to engineer it such that the warning indicator light for a system goes out when the system dies!

Thanks for your help, and hopefully this helps someone in the future (seems like a relatively common problem).

UWMU

And thanks Shadoh, you were right on. I originally did pull the fuses but somehow missed the ECU at that time

UWMU

Well I keep blowing the 7.5W ECU fuse. I was sure it was the alternator because it got to the point where it would blow that fuse as soon as I turned the ignition on. So then I put in a new alternator and made drove about 25 miles before I blew the fuse again, triggering the D4 light and transmission codes.

So it doesn't seem like the altnernator causing the problems. Do you think it's the solenoids that need to be replaced? Or might it be something else like the ECU causing this fuse to blow? Any experience with this?

bebo1589CL3.0

its your transmission they are pieces of shit on cls i have a 97 v6 n my tranny went out at 105k my srs,check engine,abs light all went off when the tranny went i had it rebuilt was runnin perfect for about a week then all the lights came back and now the tranny works alryt hesitating to change gears around 5k but good but my speedometer doesnt work i cant tell how fast im going the rpms work fine but my mph stays at 0 does anybody have anything ?

TexasHonda

You will need to determine what circuit on the ECU fuse has a short. Process is usually to disable circuits; pull bulbs, disconnect components, etc.

I don't have your specific vehicle manual, but in looking a 94 Accord manual the ECU fuse (7.5A BackUp fuse) only services the ECU. Yours may be same. In that case you either a wiring fault (wire pinched against ground) or defective ECU (rare but it happens). If unplugging the ECU stops the fuse from blowing, you've confirmed ECU as the fault. If fuse blows w/ ECU absent, then wiring is problem.

ECU has short/open circuit protection in the circuits so even a short in the solenoids should not cause the ECU fuse to blow. That's why it can detect an electrical fault and set a code w/o any problems.

You should be able to find a specific wiring diagram at autozone.com w/ their online manuals.

good luck

UWMU

I've unplugged pretty much all of the transmission solenoids and the alternator to see if any of those are overloading the circuit, but I keep blowing the fuse no matter what's unplugged. So that seems to point toward a wiring issue, it seems.

I also unplugged the ECU but obviously the car doesn't turn on without it...so is there any way to have the ECU unplugged and test whether that's overloading the circuit? I noticed the car turns on with only the smaller ECU plug plugged in but I'm no sure whether it's safe to drive the car without the second plug in.

hwdp420pl

Transmission speed sensor

UWMU

OP here. Just in case this problem happens this happens to anyone else in the future, it was a shorted rear O2 sensor that caused all the problems. I replaced it a few weeks ago and haven't had any problems since then. Thanks everyone for your help!

e30cabrio

iTrader: (6)

So the moral of the story is do regular maintenance & if something breaks replace it?

Congratulations on resolving the issue.

UWMU

I wasn't in any big hurry to replace a part that wasn't affecting the car's performance or gas mileage. The sensor was shot for several months and didn't cause any problems. And after the other problems arose, I didn't want to put in a new O2 sensor if the real issue was the transmission, in which case I probably would considered buying another car.

I've seen people with these codes in other forums who simply got a new transmission or paid hundreds for new solenoids, so I'm just posting the fix to save others some time and money. None of the Acura mechanics I took the car to thought it had anything to do with the O2 sensor and thought that it was either the ECU or wiring. If it was so obvious that the problem was the O2 sensor, someone would have recognized it as that sooner.

e30cabrio

iTrader: (6)

The 02 sensor directly affects mileage. Look up it's function.

You said you had an 02 sensor CEL prior to the issue & the solution was the 02 sensor.

I am not trying to give you a hard time but it seems pretty clear your problem was caused by a lack of basic maintenance.

Modern cars are complicated and have many systems that are interconnected. My gen2 CLS had "transmission" issues that I finally diagnosed and fixed by replacing the TPS (throttle position sensor) I was told to suck it up & replace my "dead "transmission.

That was over 6 thousand miles ago, car runs great.

People just assume the faulty transmission is at fault the second anyone says they have a shift issue or a D4/D5 light on.

I agree with you that is silly & expensive.

WineRed2.2CL

great info

terb0328

Thank you! I just bought this car yesterday and my exhaust pipe fell off somewhere along the lines. Thinking is up by the caddy. Then on my way home my lights were dimming needles were going crazy. I luckily enough made it home. Glad I found this thread!

Mach30SiR

Thanks for sharing,

My 3.0 broke down on the side of the 5 yesterday, had to leave it and get it towed.

I was having trouble like the OP had, shifting wacky, then the windows were slow to roll up and eventually I had no lights in the dash before it died. I initially thought it was the alternator but I also replaced my rear O2 sensor last month. I have no CELs or flashing D4 or anything, so I'm thinking its not the exact same issue. I didn't have a chance to check the fuse before getting picked up,

I'm in Europe for the next 12 days and I think the car is at a dealer in the San Diego area. I wanted to bump this for ideas. Should I pay Acura to do the diagnostic and get me a cause and fix it myself, or is that a waste of time? I'm moving to SD so I don't have any of my tools with me.