'Check' light illuminated

[Rapidair65]

The 'check' light on our 2004 2 litre illuminated this morning.'No probs' I thought, open the diagnostics plug, test with voltmeter per the fact sheet, sorted. Unfortunately not, as the diagnostics plug bears no relation to the layout shown in the fact sheet. Does anyone have a diagram for the later models showing which terminals to bridge with the voltmeter?

[g8dhe]

There mounted upside down, normally, unless they have changed it in the very latest models.

[Rapidair65]

Geoff,
I can orientate the plug no problem but there are terminals missing or moved. Looking at the fact sheet diagram, FEN is not there.On the second row, FSC is missing but there is an extra terminal next to FBS. On the third row TSC is missing but there is an extra terminal next to TBS. On the fourth row TAB is missing.

[g8dhe]

What is fitted will depend on what options are fitted to the vehicle and the particular ECU sometimes (I think), having looked briefly at several ECU's for the same engine types some clearly have a lot more onboard which makes me think that the PCM and TCM may have been combined but still having the same sockets, but only one output to the diagnostic panel. This is only assumptions, as I have decided not to go down the route of drawing out the various boards, as in most cases people are not going to be repairing them and the code on all the ones I've seen are in masked ROM so little chance of changing anything even if your able to read out the program memory itself.

[Rapidair65]

I think I may have sorted the problem by checking each engine sensor. We have had a mis reading temp gauge for some time and I have just checked the resistance across the sensor and it is way lower than it should be with a cold engine. Correct reading at 20 degrees =2.2 -2.7 KOhm,mine is reading 0.67 KOhm. I'll replace the sensor and see if the check light extinguishes. The engine starts and runs OK with a steady idle which may rule out crank or cam sensors and the MAF sensor. as an aside, has anyone carried out the temp gauge modification with the shorting link and resistor on a late model Bongo? I modified the gauge on our '98 V6 no problem but I read somewhere that the later bongos had a different instrument panel.

[Simon Jones]

I've got a Mason alarm on my '02 V6 which includes the same type of mod as you are planning. I had one on a previous '98 diesel & that worked the same.

The later instrument panels are slightly different in terms of the addition of a gear selector indicator round about 1999, but the instruments themselves are identical as far as I'm aware.

[Rapidair65]

Thanks Simon, I have just tried the fault code reset procedure per the fact sheet and the check light has gone out. The temp sensor is still reading 0.9 kohm with the ambient temp less than 20 degrees C so it looks like the sensor is duff. I have a part number JE151851X which appears to be the same for the V6.

[Rapidair65]

Still having problems with the 'Check' light. Replaced the engine temp sensor as the temp gauge was erratic. The light still illuminated after 5 seconds. Reset procedure puts it out but it comes back on virtually immediately. Is there a suitable diagnostic reader and adaptor to enable interrogation of the ECU and production of a fault code? I can find readers on Amazon which state 'suitable for Asian vehicles after 1998. OBD2, OBD-II' and Mazda adaptor leads but I do not want to spend money on on a machine which will not work. I have exhausted all the options for shorting out the terminals in the diagnostic plug, none of them give me a flashing 'Check' light.I do not want to go through replacing each engine sensor in turn hoping it will fix the fault and I do not want to drive the van in case the problem causes damage elsewhere.

[rita]

Thanks Simon, I have just tried the fault code reset procedure per the fact sheet and the check light has gone out. The temp sensor is still reading 0.9 kohm with the ambient temp less than 20 degrees C so it looks like the sensor is duff. I have a part number JE151851X which appears to be the same for the V6.

The temp sensor (ECT)is ....B59318840a The gauge sensor is..JE151851X

Might be worth having check.

[Northern Bongolow]

thats what i would go for too rita, one is just for the dash temp reading only and is not connected to the ecu. the engine temp sensor is.

[Rapidair65]

Many thanks for all the help and advice so far. I'm hoping to get a fault code reader so I can pin down exactly which component is causing the engine management light to come on. The engine coolant sensor was a stab in the dark as it was cheap and easy to get at!

[Rapidair65]

Received the code reader today. Plugged in using the Mazda adaptor, nothing. Checked the diagnostic plug 30 amp supply terminal, nothing. Checked footwell fuse 15A,OK. Checked under bonnet 30A fuse, OK. Does the diagnostic supply come from the ECU or direct from the fuse box?

[g8dhe]

I don't think there are any wiring diagrams for 2004 vehicles so its a bit of a guess, but all the other earlier versions are as below;

[Rapidair65]

Thanks Geoff,
Looking at the switch top right, am I correct in assuming that power only goes to the diagnostic if the ignition is set to 'on'? I have had a reply on Facebook stating that you need a separate power supply but my plug has the B/W wire from the switch.

[g8dhe]

Yes its switched by the Ignition switch, when on the second & third positions, i.e. beyond Ancillaries position.