14CUX diagnostics-Good news/bad news.

**PhilipA** · 29th December 2007, 05:32 PM

Since I installed my o2 sensors , I was curious whether it was also possible to use the USA RRC code reader, which came as standard on all 14CUX USA RRC.
I contacted "Car Cannibal" and paid what they asked by USD cheque (USD50 plus freight of30) ,as they didn't have Paypal or credit cards! After a month or so I followed up. Oops, will fix, sorry.
After about three months, while I was overseas in December the code reader arrived.

I installed it today and it works! When I first connected it there was nothing, so I didn't know if it was working. Brilliant idea, disconnect the MAF. Immediately an "02" Maf error came on.

The bad news is that there is no wiring in the ECU plug of the OZ spec RRC or Disco. I had to add wires and plugs at terminal 30 and 38. The other 2 wires to the reader are 12v and earth so I was able to just wire up a cig lighter plug. I was able to work out which was which from the wiring diagram, and I am happy to advise if anyone buys one.

If you are very confident of your ability to not stuff up wiring your ECU plug, then this is a worthwhile thing to do, especially if you have a problem you cannot Identify.
If you have o2 sensors , the diagnostics are very powerful, down to ID of which bank has a miss, but even without, it will identify sensor problems and other electronic problems.
My car has no codes!!!!!! so its as good as its going to be now.
Regards Philip A

**Utemad** · 14th July 2008, 08:47 AM

Well my PRC7067 code reader arrived today

$16 delivered within the US and came home via economy class today.

Just had a quick look in the RAVE CD and the wiring appears to be

1 +ve ign (black/white)
2 Ground (brown/orange)
3 ECU 30 (brown/white)
4 No connection
5 ECU 38 (pink)

Does this match the connections you made Philip?

**PhilipA** · 14th July 2008, 09:27 AM

No that is not correct.
There are only 4 wires to the 7067.
BS =black grey/white= earth
NO=12v (brown /orange)
NK=38 (brown/pink)
K=30 (pink)
The five wires go to a dealer diagnostic screen which is different.

Look at the diagram on my oxygen sensor project
Regards Philip A

**Utemad** · 14th July 2008, 10:02 AM

Thanks Philip.

The connector (C380) that I'm talking about is the same one you are talking about.
There are only 4 wires but the connector has 5 pins. Well 4 pins and an empty hole.

Your wiring is correct. Which since yours works is fairly obvious

I read the info from the RAVE CD but made the silly mistake of reading the connector diagram in RAVE to be the connector I was looking at. However RAVE has the loom connector and I have the unit connector. So of course what I wrote above is for the loom not the unit.
I thought something was wrong when it said the black/white wire was +ve.

**PhilipA** · 14th July 2008, 10:56 AM

Justin
I just fitted 2 wires ( the pink and brown pink signal wires) to the ECU plug and ran the power and earth into a cigarette lighter plug.
My ecu plug is pretty crowded with the coaxs for the o2 sensors.
Regards Philip A

**Utemad** · 14th July 2008, 11:05 AM

I plan to hard wire mine in as I know it will get lost damaged otherwise.
To clear the faults it says you have to unplug it so I plan to put in a switch. Do you know which wire/s have to be cut to clear the code?
I'll figure it out by trial and error soon enough.

**Utemad** · 14th July 2008, 05:26 PM

I have connected it up. Wasn't going to but there you go.

It was blank when first connected. So I disconnected the MAF and started the engine. It came up with a 12 which is for the MAF so all is well. However now I cannot clear the fault code. I know the MAF is reconnected but it shouldn't matter if it wasn't.

The procedure according to here
Rover 14CUX Hot Wire Mass Flow EFI: Service and Troubleshooting

Use this procedure to clear faults:
1. Switch "on" the ignition.
2. Disconnect the serial link mating plug, wait five seconds, and reconnect.
3. Switch "off" the ignition, and wait several seconds.
4. Switch "on" the ignition. The display should now reset.
Note: It should either show a lower priority fault code or appear dark.

How have you been clearing the codes?

**PhilipA** · 15th July 2008, 08:00 AM

A14CUX should clear the code next time it is started if the fault has gone. I would check your MAF connections again.
Mine cleared the MAF code next time it was started.
AFAIR I just turned it off with the reader attached and next time I started it didn't show a fault
BTW the ECU will be in limp home mode if it still shows MAF fault.
Regards Philip A

**Utemad** · 15th July 2008, 09:28 PM

Thanks Philip. I've been playing with it tonight and still can't clear the code. The MAF is definitely ok as there is a big difference between when the MAF is connected and disconnected.

I've put a post up on Discoweb to see how they do it. The procedure should be common knowledge over there I'd think.

**GrahamH** · 15th July 2008, 10:46 PM

Guys,

I found this info on the Mark Thompson's website at the URL Fuel injection

ECU urban myths.
Over the years various myths have risen up about this ECU, and not all of them are true.

Examples are:

You need to drive for 20 minutes to stablise the mixture after a ECU reset.
Untrue- it takes place in about 15 seconds at tick over.

You need to reset the stepper motor if you remove it.
Untrue. The stepper is reset every time the ignition is cycled off, but sending 200 pulses into a 180 step motor, so it will always reach "home".

You need an ECU reset to clear fault codes and reset the mixture.
True - The ECU contains no volatile memory, so a 30 second power off (as in unplug it or disconnect the battery ) will remove any fault codes, and any stored fuel base settings. These will be re established once then engine is running at tick over.

I think that might be your answer - try giving the ECU a 30+sec power down reset to remove the fault code.

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