Bobb Todd

P0702

32 posts in this topic

Engine light on. Above is the stored code but when you clear the Scangauge it just comes back.Runs and shifts fine.Have twice in the previous 2 weeks shifted to 1st [and showed that in cluster] but car remained in neutral. To neutral and back to1st had it working. No codes then.Where do I start ?Bobb

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Posted (edited) · Report post

Dealer.

Only ever, as a last resort. Edited by Huronlad

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Could possibly be just a bad connection. Do you still have your original battery in the car, could be a voltage issue.

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Could possibly be just a bad connection. Do you still have your original battery in the car, could be a voltage issue.

...........Not sure if original. Maybe be. Scangauge shows voltage running 13.6-14.0.

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When the fault occurred were you braking?

.....................No. My wife started the car and it was there [the engine light]. She shut off and restarted but still there. She drove home with it on. Shifts fine. It was raining [as it was the other 2 times it happened]Bobb

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It could be a wet / corroded connection at the transmission, likely the best place to begin.

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I'm going to place this in a few different threads, as the cars age it sure seems a lot of connector issues are showing up.A general note, for any connector subject to corrosion, heat, vibration, high current or very low current (sensors and communication links in general are subject to false readings due to a tiny bit of oxidation), a product called Noalox works well. It's a conductive paste of fine zinc powder in an anti-oxidant base, prevents oxidation and improves conductivity. It's primary use is on aluminum wiring connections where it is required by electrical codes, but it works very well on all connections. There are other brands, Noalox is the most commonly available. All electrical wholesalers, many hardware shops (Home Depot has it), electronic supplies, probably some automotive shops. Dielectric grease is NOT what you want. Anti-seize compound also helps, Noalox is better. Be sure to wipe any excess off, for multiple connectors apply very carefully as it is conductive and if you bridge outside the connection itself or between adjacent pins on a multiple connector bad things will happen.

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DANGER DANGER Will Robinson.

In the late 80's BMW had a problem with the speedos (not the bathing suits) on their motorcycles.

All kidding aside.

This was very cautiously cured by the service technicians under a TSB in the same manner on that connector. I would be real judicious in this application because you could FUBAR the entire car and have no way to undo this treatment. In other words...

if it ain't broke, don't do this.(I can't post this warning along with all the other posts you said you were going add)

post-6582-1277311747_thumb.jpg

Edited by gordo.bernard

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Could be the shifter motor giving issues - check the connections to it and if you haven't already - lube the clutch actuator - it can make a world of difference (i.e. the shifter has to wait on the clutch - which if is too long can make the computer wonder what is up with the shifter).I would stay away from conductive grease simply because you can't control where it will wind up - i.e. if it gets into the base of a connector and arcs - a good clean up with a dentist probe and some regular grease is a better idea - have had a lot of practice with marine connectors (and you think cars are fun - add salt water to a electrical system!).Cheers,Cameron

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An excellent contact cleaner is Molyslip Combat. It brought a Bosch Motronic brainbox back from a thorough drowning in water. Good stuff!

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Good cautions on conductive grease, it is probably a good idea to stay away on the small multi-pin connectors. IF you get it well applied on and only on the pins in a very small amount, it will work well, but just one glob in the wrong spot...For regular, large 2-8 pin connectors, no worries, use sparingly, apply carefully, disconnect again and inspect with good light and you'll be fine. Once applied properly the stuff works very well indeed.

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Forgot to add - make sure you disconnect the battery before doing cleaning etc. with metal objects (See Bil's current avatar).One thing I find not so great is the smart doesn't use weather proof connectors - half of them the back end is open to the elements - if you are servicing the connectors once you get the clean and greased and back together - give any points that water can get in a coat of liquid electrical tape goop - not too much on the actual joint but the butt ends would be good. Cheers,Cameron

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One thing I find not so great is the smart doesn't use weather proof connectors - half of them the back end is open to the elements

This has always been a... wtf item... for me. Do you know if the 451's connectors are any better, or did they cheap out on them too?Living in the Okanagan, we don't often suffer from failure of these... vulnerable... connectors, but WHAT were they thinking, sending a car to Canada like this!?B :senile:

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The transmission connectors looked shiny and clean. The new battery didn't help. Now I have no radio [didn't get code from previous owner].Interestingly the engine light has gone out [car in garage out of rain] although the P0702 still comes up in Scanguage and can not be removed [well it can but it immediately comes back]The car does shift fine despite the code but it looks like a trip to the Oakville dealer for me. I can also get the radio code and remove the stupid safe modeBobb

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So I went to my appointment at Oakville MB today.The service advisor told me after exhaustive tests they couldn't find anything wrong. Interestingly the Scangauge error message is gone also.Surprisingly I found out my warranty didn't run out last month as my records show. It ends tomorrow !! Therefore bill was zero.I pointed out to him that the engine light and issues only occur when the car is wet but of course the free wash didn't show up any issues.Still waiting on my radio code as it hadn't arrived by the time I left and he didn't email it to me as he said he would.He said he would hold it open for a week so with my luck we will get no rain.Bobb

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It was probably a wet transmission sensor connection. You mentioned it was raining. Mine used to do it all the time. I sealed the wired that had become separated from the plug with liquid electrical tape. You paint it on and let it dry and it seals all of the entry points that water could get into. The sensor is located on the transmission housing under the car and its exposed. Ices up really bad in the winter and it will throw that code.

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I have a P0702 Error code on my smart....I check the actuator connector and lubricate it, but no change.... The clutch stop grabing at 1200rpm, like it return to neutral....Help please..

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Why has this become a common problem in the past 12 months or so?David, it's possible the actuator is kaput. But more likely you have a short or an open circuit in one of the wires from the engine harness -- the bigger plug off the ECU to the actuator, gear sensor and clutch sensor. Unplug all the connections around the gear box, cut the tie wraps and chassis connectors and bring the whole harness up on top (easier to work). Remove the plastic tubing on the wire bundles and look very carefully at every millimetre of every wire. Repair anything that looks wrong.

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Good, that's an easy repair.

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Good, that's an easy repair.

Yeah, but not a lot of room to repair the wire !Everyone should check that when changing tire. Easy to see. Edited by David_18

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If you don't get all the connections off and the clutch actuator harness on top, remove the rear panels (this makes it very easy to remove the plastic fender liner) and you can reach most of the wires from the side. That is how I did the initial fix of mine. When it warms up in a couple of weeks I will take out the whole engine harness and go over it again.Glad you found the problem!

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