General help with connection loose error.

[ArcticStilo]

so my 2002 1.6 has been doing this thing for a while and it has been getting worse.
sometimes it starts fine and sometimes it just keeps cranking for ages before starting and being in some kind of limp mode, RPM cauge dosent work, engine light comes on and the yellow triangle in the middle of the dash is illuminated, the dash read "connection loose".

i have all ready cleaned and greased the battery terminals against oxidation, i have also replaced the crankshaft position sensor last year and now checked its connection for any funny business.
battery shows a strong current when running and it cant be that bad if it can crank for so long.

so that leads to me suspecting maybe a bad ground? or what could lead to this kind of problem? if its a bad ground which of the grounds could lead to a problem like this.

many thanks in advance to anybody who has any idea!

 

[bugsymike]

so my 2002 1.6 has been doing this thing for a while and it has been getting worse.
sometimes it starts fine and sometimes it just keeps cranking for ages before starting and being in some kind of limp mode, RPM cauge dosent work, engine light comes on and the yellow triangle in the middle of the dash is illuminated, the dash read "connection loose".

i have all ready cleaned and greased the battery terminals against oxidation, i have also replaced the crankshaft position sensor last year and now checked its connection for any funny business.
battery shows a strong current when running and it cant be that bad if it can crank for so long.

so that leads to me suspecting maybe a bad ground? or what could lead to this kind of problem? if its a bad ground which of the grounds could lead to a problem like this.

many thanks in advance to anybody who has any idea!

Others may have more advice , but if engine cranking over but RPM gauge not moving usually indicates the signal from the crank position sensor is at fault, so whether a dodgy sensor or the wiring to it, that is where I would start my checking.

 

[ArcticStilo]

Others may have more advice , but if engine cranking over but RPM gauge not moving usually indicates the signal from the crank position sensor is at fault, so whether a dodgy sensor or the wiring to it, that is where I would start my checking.

the sensor is basicly new so i really hope its not that but i think ill have to follow the wire a bit longer than the socket for the sensor.
hope the car gets me to my workshop atleast today and maybe tomorrow

 

[Ralf S.]

Mine did this and it was literally a loose connection.

Loosen the positive battery terminal so it's a bit loose then use a mallet and a piece of wood to drive it further down onto the battery terminal (that should have a slight chamfer on it) so it becomes tight by being wedged on, rather than because of the screw. Then tighten the screw up.

Also check the battery earth, not just at the battery but at the gearbox (?) end.


Ralf S.

 

[ArcticStilo]

Mine did this and it was literally a loose connection.

Loosen the positive battery terminal so it's a bit loose then use a mallet and a piece of wood to drive it further down onto the battery terminal (that should have a slight chamfer on it) so it becomes tight by being wedged on, rather than because of the screw. Then tighten the screw up.

Also check the battery earth, not just at the battery but at the gearbox (?) end.


Ralf S.

my battery terminals are so god darn tight that you could propably lift the whole battery by them, this has been done in an attempt to make that code go away.
now that its warmer (15-25c) the problem has gotten less common, i am starting to feel that this might just be a condensation building up somewhere type of problem.
really kind off hope that that error might stay dormant for at least 3 days so that i can get the car inspected.

 

[bugsymike]

my battery terminals are so god darn tight that you could propably lift the whole battery by them, this has been done in an attempt to make that code go away.
now that its warmer (15-25c) the problem has gotten less common, i am starting to feel that this might just be a condensation building up somewhere type of problem.
really kind off hope that that error might stay dormant for at least 3 days so that i can get the car inspected.

Personally I an not a fan of too tight battery terminals, as long as the post and clamp are clean I just push them on and nip them up lightly, then if a wiring emergency, electrical fire, etc. and a quick pull and the lead will come off. This approach works fine even starting a 2.8litre diesel van in middle of winter. Hammering terminals on hard can damage the battery internally on the plates inside.
It is quite easy to spread the clamp with a thin screwdriver to drop it on the post and then nip up the nut with no damage.
Going back to the starting issue, if engine cranking well but not starting then not a battery issue, however if rev counter doesn't react when engine will not start , then it indicates a crank position sensor or wiring to it from computer I would have thought.

 

[ArcticStilo]

Personally I an not a fan of too tight battery terminals, as long as the post and clamp are clean I just push them on and nip them up lightly, then if a wiring emergency, electrical fire, etc. and a quick pull and the lead will come off. This approach works fine even starting a 2.8litre diesel van in middle of winter. Hammering terminals on hard can damage the battery internally on the plates inside.
It is quite easy to spread the clamp with a thin screwdriver to drop it on the post and then nip up the nut with no damage.
Going back to the starting issue, if engine cranking well but not starting then not a battery issue, however if rev counter doesn't react when engine will not start , then it indicates a crank position sensor or wiring to it from computer I would have thought.

Currently have the sensor in my hand and trying to get readings from it with multimeter. The resistance is 1207ohms is that too much?
Got an obd2 scanner on loan and its also showing the p0335 errorcode.

 

[bugsymike]

Currently have the sensor in my hand and trying to get readings from it with multimeter. The resistance is 1207ohms is that too much?
Got an obd2 scanner on loan and its also showing the p0335 errorcode.

So it is pointing in that general direction with that error code.
I was thinking a 5 volt supply at plug and I don't usually check the resistance, but this is on the internet as a guide. But I am sure you will know that.
My other thoughts are if the clearance between the sensor and the rotor vane that triggers it is may be wrong or damaged, assuming wiring is in good order.
"When testing the crankshaft position sensor (CKP) plug, you should expect to see specific readings depending on the sensor type and testing method. For inductive sensors, you'll typically find a resistance between 200 and 1,000 ohms. When testing with AC voltage, you should see a low AC voltage signal when the engine is cranking. With Hall-effect sensors, you might see a 5-volt power supply and a signal voltage that varies with engine speed."

 

[aschiuta]

Currently have the sensor in my hand and trying to get readings from it with multimeter. The resistance is 1207ohms is that too much?
Got an obd2 scanner on loan and its also showing the p0335 errorcode.

Disconnect the battery then disconnect the electric couplings from ECU and use spray for electronic contacts for clean the electric contacts from ECU and from ECU connectors. As you see on diagrams the K46 is the rpm ( speed ) sensor.
Use the spray also on K46 connectors. Do not use WD40. It is good ideea to clean also the connectors inside the engine bay fuse box. I use Liqui Moly pn 3110 spray because it contain silicone oil and protect against moisture.