Engine Management Light On, Obd Code P1161 And P2101

[Peterv]

Has happened twice now, can turn it of with my OBD reader but seems to be a problem with the throttlebody!?

Any ideas of what is wrong?

 

Car is from 2004 with 70hp 1.4 gasoline engine.

 

regards

Peter

Edited November 24, 2014 by Peterv

[paul.h]

Welcome to the forum.

 

An internet search on P1161 suggests it may be a problem with a 4 pin wiring connector in the passenger compartment from the accelerator pedal to the throttle body that looks like the one on the pedal and is used on right hand drive cars. The suggestion is to remove the connector and solder the wires. Whether or not this is the cause of the fault code I do not know, but if you can find the connector it is worth checking the pins are clean and it is not loose as well as at the pedal and throttle body ends. Failing that it may be the throttle body - but I would clean this out with carb cleaner first to remove any build up of carbon in the body and plate which could cause sticking and tickover problems.

 

A search on P2101 has come up with the same answer.

 

If your car is left hand drive (just noticed you are in Sweden) then check the wiring connectors at the pedal and throttle body.

[Peterv]

Thanks, i have checked and cleaned the connectors but did not think of the throttlebody and plate. Will give it a clean aswell.:-)

 

I checked the voltage of the battery with engine off and it shows only 11,93v!? I'm thinking that this might cause the MIL light to go on?

I think it's the original battery so it's pretty old.

Edited November 26, 2014 by Peterv

[paul.h]

If you are only doing short journeys the battery may benefit with charging up off the car, otherwise I would consider replacing it. The original one can be replaced with one with a much higher Ah capacity and this will help with starting, especially when the outside temperature drops in the winter which lowers the battery voltage. At below 12 volts you are lucky the car started.

 

Low voltage should not cause the MIL to come on but on starting you may get a warning bleep, our 2003 C3 with the same engine used to do that.

[Peterv]

The car starts easy with the battery, only thing I have noticed is that the idle is a bit rough the first couple of minutes.

Will buy a new battery tomorrow and I'll check the alternator too.:-)

[paul.h]

'The car starts easy with the battery'

 

This does not tie up with the measured voltage, I would have thought it would be slow turning over on the starter motor. Is the voltage being measured on the battery terminals, if not then there is usually a voltage loss through the car or if a door or something has just been opened the car electrics/bsi will be doing things that cause a drop. I find it best to lift the bonnet and wait a few minutes for everything to shut down before checking the voltage. To check the alternator, again measure the voltage on the battery terminals with the engine running and you should get about 14.3 volts if it is ok.

 

If your code reader does live data you could check the engine sensor temperatures. Before starting with a cold engine, the engine should be ambient temp so about 10°C, similarly the air inlet temp (AIT). The engine will then go up to about 96°C when the engine fan will start but the AIT will remain about ambient or a bit higher. 

[Peterv]

I did measure on the battery terminals, I had started the car, driven it out of the garage and parked it on the driveway. after about 15-25 min I checked the battery voltage.

 

My code reader(Torque on my Android phone with a bluetooth OBD unit) does do live readings but why check those temperatures?

[paul.h]

If the temperature sensors are giving wrong information the air/fuel ratio could be wrong and hence a possible reason for the rough idle. The engine coolant temperature sensor has been noted  a few times on here as failing (not just on the C3) but it is often found by indicating a high temperature whilst the engine is still cold.

[Peterv]

Well it happened yesterday again but it's probably not the battery. Car had been standing at work fo 8 hours, when I got out it started fine but the idle was a teeny weeny rough. Reversed out of the parking spot and drove of, got about 10 meters and the MIL came on and car went back to idle. When pressing the accelerator nothing happens, it just keeps idling or maybe it went up 50-100 rpm.

 

I forgot to check the temp sensors but will do today, have checked the throttlebody plate but it was nice and clean so no stickiness there.

Charged the battery over night and this morning I disconnected the charger, disconnected the + cable and checked the voltage which was 12,7v. Left the car standing for an hour or two and checked the voltage again and it was 12,5v. Temperature was and is around zero degrees celcius.

 

Also checked the alternator yesterday evening and was a bit worried at first. On idle with lights on I only got 13,3v, with lights out 14v. Tried this mornig again but reved the car to around 13-1500 rpm and got 14,24v so alternator seems fine to me.

[Peterv]

Forgot to mention that yesterday when the MIL came on the warning light for passengerairbag disabled came on!? I could only turn it off by using the key by first turning it off with key and aneble it again.

 

So bought a new battery today, the old one was alot smaller so wasn't the OEM battery. The new one is 60ah and fitted right in.

Fingers crossed!:-)

Edited November 27, 2014 by Peterv

[paul.h]

If the passenger air bag disabled light comes back on, you could check that its electrical connector is not loose and that its pins are clean and not bent. I vaguely remember something like this before so it is worth a check, but do it with the key out of the ignition for maybe 30 minutes so the air bag system is powered down.

 

In the Citroens we have had, the original batteries seem to be Varta ones. Hopefully the new battery will solve the problems. In a recent Car Mechanics magazine where a Ford was not doing anything when the accelerator was pressed, a suggestion was that a low battery voltage could be the cause but I do not know if this would apply to a Citroen.

[Peterv]

So far no fault codes but....

 

On idle(around 7-800rpm) the voltage is 13,2v, if i rev it over 1000 rpm the voltage is 14,1-14,2v.

Is that normal or is the alternator on it's way out?

[paul.h]

Something is not right. When I have ever checked a battery on any car on idle, the voltage has been about 14.3 volts but that is without the lights or other things switched on.

 

You could check the alternator connection, the battery terminals, earth points and engine earth point are all clean and the cables in good condition and that the alternator drive belt is in good condition and not slipping (from the Haynes manual, if it has the manual adjuster there should be 5 mm free play at the bottom run between the crank pulley and air con compressor). Then consider if the alternator needs replacing. You can get its internal parts but they can cost as much as a replacement alternator. It may also be possible somebody has replaced the alternator in the past and not put the right one on - a member had this on a C5 recently where a lower amp one was supplied than needed.

[Peterv]

The voltage is pretty constant 14,1v but on idle it it drops to 12,8-13,5v. As soon as I rev it above 1000rpm it goes to 14,1v.

So my guess is to take it off and check the brushes and as you said all connections.