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Discussion Starter #1
1994 Alfa Romeo 164 Super 24v

Automatic transmission warning lamp is randomly iluminating- i.e. red light on dash board appears, "Auto/Sport/Ice" dash indicator goes out, and gear changes become very rough.

If I pull over and turn off the engine and then restart the engine the transmission returns to normal with smooth shifting, etc. Then, a short distance later repeats - over and over.

When driving with warning lamp on gear changes are rough and if stationary the transmission bangs between Neutral-Drive, Drive-Neutral, etc.

Again if I turn the engine off and restart the car drives away smoothly as though nothing is wrong?

Tramsmission fluid appears clean and at correct level.

I understand that one symptom/condition of the warning lamp going on is that the tramsmission has reached maximum operating temperature, but I don't think this is the case - outside temperates are cool here at the moment, only driven a short distance, and driving with a light right foot...

Any ideas/suggestion would be most appreciated.

Thanks.
 

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1994 Alfa Romeo 164 Super 24v

Automatic transmission warning lamp is randomly iluminating- i.e. red light on dash board appears, "Auto/Sport/Ice" dash indicator goes out, and gear changes become very rough.

If I pull over and turn off the engine and then restart the engine the transmission returns to normal with smooth shifting, etc. Then, a short distance later repeats - over and over.

When driving with warning lamp on gear changes are rough and if stationary the transmission bangs between Neutral-Drive, Drive-Neutral, etc.

Again if I turn the engine off and restart the car drives away smoothly as though nothing is wrong?

Tramsmission fluid appears clean and at correct level.

I understand that one symptom/condition of the warning lamp going on is that the tramsmission has reached maximum operating temperature, but I don't think this is the case - outside temperates are cool here at the moment, only driven a short distance, and driving with a light right foot...

Any ideas/suggestion would be most appreciated.

Thanks.
Unless you have access to Mareilli Tester with cartridge for Automatic tranny you are going to be hard pressed to troubleshoot system.

However, does speedo needle drop off before problem occurs?

Have you tried to drive in Sport or Ice modes to see if problem occurs in those modes too?
 

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check the AT computer

Check behind/under the radio on the AT computer - If there has been any leakage from the heater core or associated plumbing, this area gets wet usually. IF there is signs of discoloration/etc (ie looks like it got wet but is now dry) you might open up the computer box and make sure that no crystals/fuzz etc are present on the circuit board. Also look at the computer connector and do a good clean there

WHat you described happened to me 6 years ago and a good clean of the board and connector fixed it
 

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Also check the security of the wiring plug on top of the A/T box just by the air cleaner. There is a 7 wire connector there that I had trouble with, and a good reconnection of the wires to the plug was necessary. Very fiddly to do. My A/T was behaving like yours seems to.
 

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Discussion Starter #5
Unless you have access to Mareilli Tester with cartridge for Automatic tranny you are going to be hard pressed to troubleshoot system.

However, does speedo needle drop off before problem occurs?

Have you tried to drive in Sport or Ice modes to see if problem occurs in those modes too?
Steve,

Thanks for advice on Mareilli Tester, I will follow up on this option if I'm not sucessful in sorting issue with other comments provided.

The speedo needle does not drop off before the problem occurs. After re-starting car (from error mode) I drove in Sports mode but still got the same fault.

See my reply to goatster as his comments seem similar to my problem.

Thanks again.

Regards,
Greg
 

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Discussion Starter #6
Check behind/under the radio on the AT computer - If there has been any leakage from the heater core or associated plumbing, this area gets wet usually. IF there is signs of discoloration/etc (ie looks like it got wet but is now dry) you might open up the computer box and make sure that no crystals/fuzz etc are present on the circuit board. Also look at the computer connector and do a good clean there

WHat you described happened to me 6 years ago and a good clean of the board and connector fixed it
Goatster,

My heater was leaking into passenger footwell for several days/weeks - initially I thought I had an exterior water leak until I smelt antifreeze.

Anyway, I got the heater core bypassed and just recently have had a good quality recondition core installed. When I realized the core was leaking I covered the CPU to avoid water damage.

You mention the AT computer behind the radio - is that the same thing? I.e. is there only one CPU /(AT) box back there?

I will check this as you mention for discoloration, etc. Is there anything I should be mindful of while checking the box/taking the cover off, etc?

This sounds promising I will report back as soon as I have checked it out.

Regards,

Greg
 

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Discussion Starter #7
Also check the security of the wiring plug on top of the A/T box just by the air cleaner. There is a 7 wire connector there that I had trouble with, and a good reconnection of the wires to the plug was necessary. Very fiddly to do. My A/T was behaving like yours seems to.
Alex,

Thanks also for your feedback. I will check that plug as well.

Regards,

Greg
 

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yep there is

Theres a handful of electronic control boxes back there including the motronic ; the air bag controller, the Auto trans computer and just to the right (or might be to the left in RHD drive car) there is the brake lights controller module and one other one (i;ve forgotten which)

I have also forgotten how these are situated, but if memory serves me, the auto trans is below the Motronic..? I don;t have my manual handy

Take off the pass side tunnel cover/carpet deal and look inside there, you'll see the boxes and connectors.
 

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Discussion Starter #9
I took off passenger side tunnel cover - there was a vertically mounted box (motronic I believe) against the tunnel. I checked inside and connectors, etc - all appeared very clean.

I they took off drivers side tunnel as earier to access another rectangular box - positioned horizontal/flat on top of tunnel directly behind radio and under heater. This had discloration from heater leaking down on top (dried antifreeze). Open up and perfectly clean inside. Connector also clean.

Interestingly just before (or as the error occurs) I can hear an electronic/relay or whatever go "click" and then the warning lamp illuminates and Ecom/Sport/Ice goes out. It also periodically go "click click" once in error mode and the car almost seems to hesitiate for a split second (barely noticeable). This sound seems to come from under the glove box area - mid passenger side.

Any ideas if there is a relay or another computer somewhere in that region that might be the problem.

P.S: I also cleaned the connector plug on top of A/T in engine bay.

Thanks,

Greg
 

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24v 164 Computers ID and location in center console behind radio area.

On the 24v 164 the top computer under black plastic heater box is the engine ECU S11. The Automatic transmission ECU N68 is directly under it. On the bottom of the stack is air bag ECU R22 in front and directly behind it is cruise control ECU N39.

Note on 91-93 12v 164 the middle is ECU N27 and it is for ABS.
 

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24v 164 A/T computer relays (locations)

Two relays under dash. The 10A fused power supply relay 82461829 (I103) for ECU N68 is located under glove box area.

Note: Horn relay I3 and air pump relay S54 (1995 USA models) behind headlight next to air cleaner are same part number but have 30A fuses in them. Third relay 60577687 (I63) behind headlight is a fused 15A relay and is for A/T oil cooler fan.

The selected gear signal relay 60800552 (I62) is second from bottom relay in center console area next to driver's right knee on LHD model (maybe other side of console on RHD models).

Note: Radio relay I70 is the bottom relay just under I103 and is same part number if you need to swap relays for trouble shooting.
 
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