P0601and ECM

[Richard A]

I have a Chinese MGTF 135 (2010). Recently a yellow MIL has appeared, the engine image. My local garage has diagnosed the code as P0601 being an internal module memory check sum error with a possible cause being a faulty engine control module. He thought another symptom was that the battery could run down quickly which coincidentally did happen to this car during the winter.
Any advice or info will be gratefully received. Pray I do not need to replace the ECM. Richard, Newbury.

[ArntyR]

Hi Richard A. Yeah I've had one of these PO601 codes and I think you're heading for ecu replacement, sorry to say...

It occurred with my newly-acquired 2010 Chinese TF 135, that gave loads of problems from day 1, a couple of years ago.

I've since seen it in a significant number of Chinese TFs and formed my own opinion that they may be a little 'fragile' with their ecu/electronics. Many seem to have been remapped and I gather the ecu of choice to remap might be the sturdier MGR unit (my remap was via the Rover NNN100743 ecu - originally my SAIC TF had Continental NNN000830).

After mine was tested to be faulty in Sep 2018 I solved my problem the only way I knew how by buying a remapped stand-alone Rover NNN10043 ecu - which proved to be the most expensive way in my case. But it solved all my problems .

A pal on this forum (hi mark vrs) has very recently discovered that a used TF-mapped MEMS3 ecu could be synch'd to his (check-sum errored) Chinese TF (or even SAWS-remapped) using the 'learn EMS' option in PScan and I've recently 'gone the other way' by buying a new Continental ecu and synch'ing it (without the check-sum error, sensitive engine fan/hot running and the slightly frantic tick-over that I experienced with the faulty unit) to run perfectly w/out any fault codes in order to get back to 'stock' - again using PScan diagnostics. I now have a 'spare'

There are a few used Chinese ecus about that are for sale but they tend to include the scu and key fobs in the package in order to avoid diagnostic synch'ing and seem to be twice the price of my new SAIC unit that I used PScan to synch.

From what I've learned very recently, a good used MGR unit remapped* with a TF map (google 'Technozen', he's my go-to person for ecu stuff...) will be the most cost-effective solution to your SAIC 'check-sum woes' and may well solve those other uncomfortable issues that many of us have been experiencing. If you have a pal close by with PScan (or T4) you'll be sussed - but I gather the unit can be 'standaloned' at the same time as the remap/TF map check.

ps I'm not certain that the (used) NNN100730 ecu doesn't contain a generic map that'll 'feed' your TF - but imo it'd be wise to send it to be checked...unless anybody with more knowledge and experience can suggest otherwise. (I'd certainly be inquisitive enough to try synch'ing it raw if I had one of these ecus spare...)

pps *We think we've found out that SAIC units can't be remapped through the OBDII port and I feel they might respond to attempted scan by defaulting to check sum error - but I'll be happy to be corrected

Hope this helps.

[talkingcars]

Hi and welcome to the forum Richard

I am sorry to hear you are having problems.

As per ArntyR above check out www.technozen-electronics.co.uk and www.pscan.uk
There is a pscan forum on www.the-t-bar.com

Let us know how you get on

James

[markvrs]

Hi Richard A,

To give you some hope, I also had that code/MIL when I changed the battery. Used P-scan to reset it and it never came back. If it is running OK and no other applicable codes then I would be putting it down to low voltage issue. If it is only a pending code so may only have happened once and now be ok and ECU is waiting to see what happens.

I also had a checksum error without a MIL light after a remap. Has the car been remapped. Often re-mappers offer MIL light delete to prevent this issue on a remap when ECU is non standard and can throw an error.

(Also on Chinese MG TF)

Cheers Mark

[ArntyR]

Lightbulb moment (thanks markvrs...)

My SAIC TF 135 had been fitted with a new battery just before I took delivery . Checksum error was a pending fault but it kept reappearing and this is why I sent the ecu away to be tested. It was described as faulty but couldn't be fixed because an access code to the ecu internals wasn't available. I wonder if the act of attempting to apply an access code triggers 'checksum error'?

I also seem to remember at this time that a different remap specialist told me that my original SAIC ecu 'may have been damaged due to an unsuccessful attempt at a remap' - and we now know that Continental ecus are very different to MGR ecus, especially with the realization that they can't be remapped in the same way (or at all(?), wrt current SAIC revelations)

Interesting comparisons...

[Richard A]

Many thanks to ArntyR, James and Mark for your helpful replies.
It is frustrating that the SAIC units seem so unreliable when it comes to remapping and accessing the ECM. At the moment it looks like my simplest, most reliable, but most expensive route is to buy a remapped MGR ECM from someone like K Map who appear to be able to leave the SCU settings and key fobs as they are.
I will have a chat with my local garage mechanic, another Mark, who is very interested as he has a Lotus Elise with the same engine. Maybe I can persuade him to get a PScan.
I keep coming back to my dead battery problem at the end of 2020. The battery was less than 3 years old and had been left without a charger attached for about 2 months. I could not find a drain path but the battery was so dead it could not be revived. So a new battery was fitted and has been kept on a conditioner when car not in use. However MIL light started after this episode. It raises the chicken and egg question. Did the ECU cause a battery drain or did the dead battery cause the MIL light?
Many thanks, Richard.

[ArntyR]

Hmm...could it be that dreaded loom on the lhs by the boot hinge that might be causing your charge leak problems, I wonder?

I presume you've tried reconnecting the battery a few times and/or Mark's advice to try resetting the error code but if you decide to completely replace your SAIC/Continental ecu, and it's hanging around useless, I'd be grateful for an opportunity to try my PScan on it. I'm just curious about their foibles. I wish I'd kept mine that was originally diagnosed as broken - but I didn't have the experience of PScan/scu stuff then. Hey-ho, isn't hindsight wonderful?

ps tried substituting your battery with your Lotus pal's? A long shot but it's not unknown for a new battery to be faulty...
pps With 3 possible similarities I'm becoming more strongly suspicious that a really flattened battery might cause the checksum error code to be defaulted in SAIC ecus. I also know that ecu fault codes can be cleared in the SAIC when I had recent defective cam-sensor issue (I replaced it with a new one, cleared it and it didn't return...)

[ArntyR]

Hi Richard A. When I had your problem 2.5yrs ago the only way I could solve it was the same way you're planning. I got a remap tho'

Things have changed - eg If you had this

Genuine MG TF MGTF 1.8 Engine Management ECU NNN100743 E08D
Be the first to write a review.
Condition:Used
Price:
£55.00

and a pal in your area with a PScan (or T4/T5?) you could be buzzing around back on the road w/out massive cost.

And if you also wanted to go down the remap route, due to a very recent PScan application you would have the opportunity to remap your ecu through your OBDII port w/out sending it away. Check out the SAWS website.

This is the option that wasn't available at the time to solve my dilemma.

Also if you can get into the PScan 'arena' you can reset that pesky SAIC service interval light and synch a (NEW only) remote if you need a spare.

[Richard A]

Thanks ArntyR, I will try the battery connect disconnect a few times and check any current drain at the same time. It would be great if that works.

The local garage reset the error code and it returned immediately, however, they were using a general purpose code reader not Pscan so do not know if that makes a difference. Must admit that Pscan is probably beyond my technical ability, without a guidance manual written for a simpleton.

If above fails then heading towards a replacement with MGR ECM as available from Kmap but am curious why you did not stick to this solution since then, or are you just ensuring you have a back-up.

[ArntyR]

Yep, good if the reconnection idea works. I must say I hadn't heard too much about it but that's the beauty of sharing on these forums.

I use both TorquePro and PScan and I've found that they're not selective with error codes - they report all, sorry to say. PScan doesn't have a manual, and is still developing it seems, but it's easy to 'get' the basics and ask about specifics on the PScan/Tbar forum. I became a convert when I knew it could cancel that pesky oil service reminder and 'LE500/SAIC' was included. (It was only a matter of time for me after that.) Glad I did, tho' because I wouldn't have been able to experience 'synching' ecus etc in my own case - and following markvrs' journey, which was refreshingly pioneering...

I feel I originally did the KMaps standalone replacement all wrong and spent hugely since there wasn't a(ny) better v-f-m option at the time. I was happy with the better drivability of the remap and the 'stronger' hardware, but that insurance 'no modification' question unsettled me. My car went like a sick pig on the way home after I took delivery. Plugs, filter, binding brakes, constant fan, racing idle, hot running...and I took it off the road to 'sort it' whilst finding out about the checksum error and sending the ecu away, renewing coolant sensor, plugs, freeing calipers, fitting discs + pads etc etc. I was desperate to get it going and saw the expensive standalone (I now feel that it might have been replaced by an MGR remap more cheaply to the same effect) as my panacea.

So, recently armed with the confidence of PScan and a similarly-curious forum pal I took a gamble by buying synching a brand new SAIC NNN00830 for ~£100 to get back to 'standard' and satisfy my curiosity about whether the SAIC should have a 'sensitive' fan, higher tickover run warmer as widely reported (but with checksum error in all cases). I'm pleased to report that tickover, fan, temperature are all absolutely normal again which has made me think that the act of applying an 'access code' and/or remap might serve to trigger 'checksum error'...we also verified that the NNN100743 (there are the option of different part numbers for TF 135 it seems) was an option that 'worked' for SAIC remap - and perhaps without remap (...need verification of this to see if the map is generic to all Rover 25/45/1.4/1.6/1.8 or specific to TF 135 etc...)

I feel it'd be safest to replace like-with-like tho' - and if I had a used standard MGR TF 135 NNN100743 MEMS3 ecu I'd certainly be curious to see if it worked ok on my SAIC TF.

The new SAIC ecu route is another v-f-m option for you - but remap is a worthwhile upgrade, too if the price works for you.

ps lurve your colour/wheel combination!!! Haven't seen it before but then I don't see many SAICS about...

[Richard A]

Many thanks. A friend is having some work done on his SAIC TF next week and the mechanic has said he can read my EMU hopefully with a Pscan. So will drive my TF over and see what can be done. Will let you know the outcome.

[ArntyR]

If your pal's got a SAIC too it'd be really easy to swap ecus over and see if your car replicates it's problem on his ecu? You can use an OBD reader to cancel the code when you replace it...

[Richard A]

Pscan showed fault with the camshaft position (speed sensor) which could account for check sum error and MIL light. Uneven tickover also. Next step is sensor replacement and re Pscan.

[ArntyR]

Yes I've recently had to replace this camshaft position sensor. It didn't throw checksum or MIL on my SAIC ecu, though.

Imo these 'let go' after a while. Like yours, mine lasted ~10years; they're not much than a small, weak, plastic-covered magnet living in a hot oily environment.

I gather uneven TF tickover is often raised by re-mappers due to lumpy TF cams.

Sorry but imo the cam sensor might be a red herring. SAIC TF 'checksum error' seems to be a hysterical reaction to some kind of an upset. -I'd really like to know what causes it. It doesn't seem to happen with earlier MGR ecus (favoured by re- mappers apparently) and it hasn't happened with my (recently brand-new) SAIC ecu. (Nearly 3 years ago my 'broken' SAIC ecu was accompanied by 'checksum error', hot running, frantic tick-over and a 'fragile' cooling fan than was almost constantly running. Some or all of these symptoms seem to have been experienced by other SAIC owners - over a very small sample range.)

Keep us posted, though...

[Richard A]

Will from Custom MG came and fitted a new camshaft sensor today. Pscan showed it to be connected ok but could not run car and see if MIL stays off. Why? Spotted that the 3 way connector for heater, as shown in ArntyR photos on previous thread re cooling system connection April 2020, is cracked and leaking. Now trying to source a PER000150 3 way Connector which is proving difficult. Should be metal not plastic. However, feel lucky to have spotted it before a sudden loss of coolant and consequences. MG Obsession list the part but their photo is of the 4 way connector so keeping fingers crossed.

[ArntyR]

Yep your cam sensor's a good, easy outcome. That 3-way connector seems a bit fragile tho. I wonder if it's a another SAIC 'upgrade'?

Some earlier MGR parts can be more substantial (I know driver door lock barrel is one...) and there are breakers who value their reputation that can supply good used parts. Personally I'd take a punt on the likes of MGObs/MGFsnTFs/Martin Smith and others to provide something good/used at a fraction of 'new' cost.

Glad the photos helped out

Hope you're back in action soon - my feeling is that the MIL will be sorted too. (I wonder if it was an over-heating reaction, which would explain the frequency of the fan?)

I've played more with ecus and PScan and managed to run my SAIC perfectly well on a 'stock' TF135 (NNN100743). Actually not too surprising since my prof remap was one of these that had been 'tweaked' a bit. Seems to be an answer to 'checksum' + 'fragile fan' if that still happens...and/or the basis for an upgrade remap (keeping the original as a spare) from one of the professionals - like markvrs has done.

(I'm back with my working SAIC atm, so the stock ecu's a spare now, as is my upgrade ecu...)

[Richard A]

Thanks for responding. Never had a problem with the fan or hot running. Original problem was just MIL illuminated. Tickover not fast just slightly uneven. Re the 3 way heater connector this is a LE500 and late TF hose part and hose layout, hence sourcing difficulties. Would be very reluctant to fit a used plastic connector as could be brittle. Funny how one problem leads to another.

[ArntyR]

Hmm...I think F3eng1911 sussed his around a year ago?

I wonder how he did it or where he got it from?

Uneven tick-over generally seems due to TF cams, I gather. Is 'checksum error' still a fault code on yours?

Funny how one problem leads to another. Yep but when it's sorted and the sun's out...

[Richard A]

Cannot run engine until broken 3 way connector replaced. So will hopefully know if checksum error still there when repaired in about a week.

[Richard A]

Update. The cam sensor replacement solved the problem of the MIL light and checksum error. Car runs fine and it seems that the acceleration is better although that could be my imagination. All due to Will of Custom MG who also sourced a 3-way T in brass to replace the cracked plastic one, which on close examination after removal is very fragile.