No connection to ECU

223vmax

2009 1.6 HDI Citroen C4 GP.

ELM 327 connected to ECU port in car, Torque app running on Android phone.

ELM 327 lights up when connected to the car. Phones bluetooth connects to ELM327. ELM 327 can not connect to car ECU.

I tried an ANCEL AD410 OBD II. Hald held light up but cant get connection to car ECU.

Anyone have any experience with these cars and no connection to ECU please?

Is it worth getting PP2000 & Lexia 3???

223vmax

Any ideas anyone???

biko

Maybe if you trying using even more question marks?????

ELM327 is not the device, it's the command protocol
So what device is it? Name and model?
Did you try the device in another car to confirm it works?
Is the error message exactly "cannot connect to ECU"?
You need to figure out if it is the app, the port, or the EU that's giving you trouble.

And now the actual question - why do you need to connect at all? What is wrong with the car?

gctest50

biko wrote: »

Maybe if you trying using even more question marks?????

ELM327 is not the device, it's the command protocol

......

ELM327 is a chip, made by ELM electronics

biko

It's a microprocessor and the protocol, I just wanted to clarify it's not the device.
Can you help OP?

gctest50

biko wrote: »

It's a microprocessor and the protocol , I just wanted to clarify it's not the device.

ELM327 is a OBD to RS232 Interpreter


SAE J1850 PWM
SAE J1850 VPW
ISO 9141-2
ISO14230-4
ISO15765-4

223vmax

EML is on. Yes, ECU socket via elm to Bluetooth works on other cars. I use the Torque app on android.

biko

Hmm, ok so it seems everything works up to the ECU.
In this case it's probably best to try with equipment from a local mech/dealer, unless you have access to more diagnostic tools?

223vmax

Brought it to a garage this evening. Can't connect to ECU.

biko

Why do you need to connect?
Is there a problem with the car?

TomOnBoard

223vmax wrote: »

Brought it to a garage this evening. Can't connect to ECU.

Did they do anything to try and resolve why they couldn't connect? Did they offer any insight?

TallGlass

Vaguely remember a YouTube review saying an adaptor for certain cars. Even though it looks like normal OBD. Check if it's compatable.

TomOnBoard

TallGlass wrote: »

Vaguely remember a YouTube review saying an adaptor for certain cars. Even though it looks like normal OBD. Check if it's compatable.

Clearly, there's an issue with the OBD port, wiring or the ECU itself if the garage's diagnostics couldn't connect either.

TallGlass

TomOnBoard wrote: »

Clearly, there's an issue with the OBD port, wiring or the ECU itself if the garage's diagnostics couldn't connect either.

Yes and it won't if you don't use the correct connection. Did you not read my post? The connection looks like a normal OBD connection but there's a similar adaptor for it.

TomOnBoard

TallGlass wrote: »

Yes and it won't if you don't use the correct connection. Did you not read my post? The connection looks like a normal OBD connection but there's a similar adaptor for it.

Yeah, I read your post. The precision of "Vaguely remember a YouTube review saying an adaptor for certain cars" left me slightly un-convinced...

Jimmy.

Car needs to be plugged in to see what’s wrong.

TallGlass

TomOnBoard wrote: »

Yeah, I read your post. The precision of "Vaguely remember a YouTube review saying an adaptor for certain cars" left me slightly un-convinced...

I agree. Sorry on mobile here. I sound like a dick. Anyway. I would see if there are adaptors or if the OP knows someone with same car, test the equipment on it see what results are achieved.

Is possible connection is toast, maybe water damaged it or something. Just baseline equipment first see if it works against another model before buying another unit and maybe having same results.

Gregor Samsa

Jimmy. wrote: »

Car needs to be plugged in to see what’s wrong.

Gregor Samsa

TallGlass wrote: »

Vaguely remember a YouTube review saying an adaptor for certain cars. Even though it looks like normal OBD. Check if it's compatable.

Older cars had various proprietary diagnostic ports. Peugeot/Citroen had a 30 pin plug. You can get an adapter for that to connect to a regular OBDII 16 pin device

http://www.kds-online.com/Shop6a/catalog/product_info.php/obd-adapter-cable-peugeotcitroen-30pol-psa-auf-obd-p-2391?language=en

But since the early 2000s, all cars are required to have a standard OBDII port, with the pinouts defined by standard SAE J1962.

There's 2 variations, 12v vehicles and 24v vehicles have slightly different notches to stop you plugging a 12v device into a 24v vehicle.

A 2006 C4 is going to have a standard 12v OBDII port like almost every other car, so there must be a physical issue with the port, the wiring or the ECU.

OP, have you tried spraying a bit of contact cleaner into the OBDII port? (disconnect the battery first)

Stoolbend

I had a problem with a grand Picasso once where there was a 12v supply missing from the diagnostic socket in the car.

I had to bridge 2 pins at the back of the socket to communicate with the car. Can’t remember which 2 but I’m sure a bit of googling you should be able to find it.

Pkiernan

Similar issue in my wife's car was blown fuse to OBD port.
Other symptom was that the headlights couldn't be turned off when ignition was on.

TomOnBoard

Pkiernan wrote: »

Similar issue in my wife's car was blown fuse to OBD port.
Other symptom was that the headlights couldn't be turned off when ignition was on.

Blown fuse would certainly be a possibility. However, I'd be surprised if the garage didnt test that when they plugged in and failed to connect.

Anyway, OP said the ELM dongle lit up when it was plugged in which would suggest that its getting a +12v from the connector. To be sure, check Pin16 on the connector for +12v.

The fact that the EML is on, and that neither O.P. nor the garage can connect would worry me that something on the CANbus may be problematic. For now, we're only guessing as OP hasnt been back since Sunday.

Stoolbend

There should be power in pin 1 and pin 16.

TomOnBoard

Stoolbend wrote: »

There should be power in pin 1 and pin 16.

The Pin16 check would be for establishing whether the OBD connector is receiving battery voltage via the fused circuit which is what the previous poster had raised as a possible cause. AFAIK, pin 1 would not be coming from the fused circuit, but from ignition.

223vmax

After a bit of digging I have +12V on pin 16, GND on pin 4 & 5 of the socket. Researching other forums I think that there is possibility that the wiring loom could be damaged at the back of the battery compartment. I came on this post in another forum (http://c4owners.org/plugins/forum/forum_viewtopic.php?171576) so will check the wiring and report back. Thanks for your posts though!;)

Row

As above check for a good 12 volts on pin 16 of the obd connector ... Have seen a few of these with no coms due to this.

Irish Steve

Nowhere in the thread have we established that the vehicle is running/mobile, or if it's been parked up for a while due to an issue.

If it's not been moving for a while, or if the battery is getting old and not holding charge as well as it should there is a possibility that the ECU has gone into economy mode, and if that happens, the ECU can't be read. There are some other issues with Citroen C4's,(I've recently got one, and I'm finding out about them as I go along). The Economy mode is strange, I need to read up more, but it seems that even the Lexia (Citroen proprietary software) can't talk to it in economy mode, and it's battery voltage related, so a way round it is to connect a stabilised power supply (not a normal battery charger) to the vehicle so that it sees a high enough voltage to get it out of economy. Mine was parked up for 6 months (no working clutch) and it was only when it was put back into regular use that it stopped dropping into economy mode.

TomOnBoard

Irish Steve wrote: »

Nowhere in the thread have we established that the vehicle is running/mobile, or if it's been parked up for a while due to an issue.

If it's not been moving for a while, or if the battery is getting old and not holding charge as well as it should there is a possibility that the ECU has gone into economy mode, and if that happens, the ECU can't be read. There are some other issues with Citroen C4's,(I've recently got one, and I'm finding out about them as I go along). The Economy mode is strange, I need to read up more, but it seems that even the Lexia (Citroen proprietary software) can't talk to it in economy mode, and it's battery voltage related, so a way round it is to connect a stabilised power supply (not a normal battery charger) to the vehicle so that it sees a high enough voltage to get it out of economy. Mine was parked up for 6 months (no working clutch) and it was only when it was put back into regular use that it stopped dropping into economy mode.

OP said a week ago: "Brought it to a garage this evening.". That suggests its mobile.

223vmax

Car runs and drives ok and has not been laid up for any length of time, but EML light is on. As I said before

"After a bit of digging I have +12V on pin 16, GND on pin 4 & 5 of the socket."

I'll check wiring loom behind battery and report back.

223vmax

I checked the wiring loom at the back of the battery compartment, and someone had already done some work on the wiring loom and all looked good. Where could I find ECU pin out/layout wiring diagram for OBD port?

MrMusician18

223vmax wrote: »

I checked the wiring loom at the back of the battery compartment, and someone had already done some work on the wiring loom and all looked good. Where could I find ECU pin out/layout wiring diagram for OBD port?

Did the garage you brought it to have lexia?
Some cars can be fussy with multimake obd readers, as I found out with a Renault I had.

223vmax

I got this connected to Lexia. I have fault "U1208 - Fault in communication with the engine management ECU or with the drive train interface ECU" It also advised ECU incoherent, although Lexia and Diagbox was able to read faults/status of the different systems. I also checked CAN bus resistance and got 63 ohms which I think is good. Deplhi and cheap hand held don't communicate with the ECU at all. Other than checking connections on BSI & ECU not sure where to go.

scannerd

Time to break out a scope and see what the data steam looks like on can hi and can low, the resistance check not that helpful

The will be a number of ecu's on the can bus, if you get communication with some then the network is ok but you have an issue with talking to 1 of the 2 mentioned.

quick and dirty - find and unplug 1 of the ecu's above and then see if you can talk to the other with the code reader, that can confirm if is just one causing the problem.