Hi All:

Newbie to this forum (and Volvos). My daughter fell in love with this car and bought it, it was fine for awhile then wouldn't start. She had it towed to a shop who diagnosed a loose connector somewhere (although they did not document which one) and said the immobilizer and key had lost commutation. The car started and ran okay for a couple of days and now it's in the crank/no start condition again. I don't know what they did to these parts but I changed the key in the fob (no difference).

There's a schrader valve on the passenger side of the fuel rail and I'm not getting any pressure. I have no idea if the fuel pump is activating or not but there's a noticeable "buzz" from the underhood fuse area (one of the relays?) and I don't know what this means. (It continues for a minute or so after turning the key off.) My cheap scanner only shows two codes (lean idle). Battery voltage is a bit low (12.05) - are these cars sensitive to low voltage? I don't know if the no fuel pressure might be caused because of some sort of immobilizer issue or because of something else. (Edit: I also noticed the tach does not move at all when cranking, not sure if this is valid or not.)

If anyone has any hints or advice for me - I would really appreciate it. I've been reading about bad crank sensors but surely that would show up as a DTC? Anyway, I'm trying to figure out what to do next and really know nothing at all about these things, so please, feel free to school me.

Frank

 

most volvo codes will not show up correctly on a cheap obd scanner if they show anything.
they are very sensitive to low voltage. put on a charger and trickle charge it for a while.
could be
-fuel pump
-fuel pickup assembly (whats the level of fuel in the tank?)
-antenna ring for the immobilizer
-something else entirely.
only pull one thread at a time, focus on that, follow it through to it's logical conclusion then onto the next.

 

Thanks for the advice. I've been trickle charging the battery all night and will try later this morning after it stops raining. Fuel level is 3/8 of a tank. The immobilizer ring was mentioned in the mechanics bill: how do I learn about that? The exact words were: "key fob immobilizer and ring lost commutation. Most likely for the poor battery life. Replacement is suggested." Maybe they meant the 12V battery was low? The alternator was charging at 14.7 vdc when running apparently. Unfortunately I'm not sure what the reference to poor battery life is supposed to mean.

 

Still not starting after charging the battery all night.

Tach not moving either, not sure if that means anything or not.

 

I found out where the immobilizer ring is located: if this goes bad will the car still crank?

 

Go back to original key that came with the car. You can't just make a key and expect it to work in these cars. If you get a new battery be sure it meets the OEM standard for your car. Not just any battery will do. Have you called the shop that did the repair ? Just suggestions. Good luck. There are a lot of these cars still on the road, so it can be fixed.

 

crank no start antenna failure fixed
(HEY ! I KNOW THAT GUY!) immobilizer antenna ring replacement

 

There's two small relays on (what I think is) the CEM - under the dash on driver's side. I can feel the two small relays activating: one seems to be when key on (fuel pump?) and I think the other activates when key in the "start" position (starter?). I'm still not detecting any pressure when depressing the schrader valve on the left side of what I think is the fuel manifold.

If the problem is indeed the immobilizer ring, does the computer cut both ignition and fuel?

Thanks everyone. When it gets a bit dryer I'm preparing to try to find the PEM which I understand may be on top of the fuel tank. The tank itself looks to be in good shape.

 

I fired the car on starting fluid this morning, the issue is definitely that the fuel pump is not being activated. I'm still trying to understand if a bad immobilizer antenna will interfere with fuel pump relay activation.

 

here's what volvo says about the immo, straight from VIDA design and function: ( what look like links here are internal links in VIDA, they won't work here, similarly no images will be shown as it was just a straight copy paste)

36: Immobilizer [img]Images/icon_back.gif[/img]
Error message in the Driver information module (DIM).
The immobilizer system

Function
The immobilizer system
The function of the immobilizer is to make the vehicle unusable unless a genuine Volvo key that belongs to the vehicle is used. When the ignition key is turned to position II, a check is performed electronically to ensure that the correct key is being used. If the key is not approved, the engine will not start. The function of the system will not be noticed by the customer as long as an approved key is used and there are no faults.Deactivation

When the ignition key is turned to position II, the central electronic module (CEM) performs an identity check of the transponder in the key via the antenna ring. In response, the central electronic module (CEM) receives a code from the transponder, which is compared to the codes that are stored in the central electronic module (CEM). If the codes correspond, the key is approved.
At the same time, the central electronic module (CEM) activates the relay for the starter motor and commences an identity check between the central electronic module (CEM) and the engine control module (ECM). The engine control module (ECM) transmits a code to the central electronic module (CEM) and receives a code back. The central electronic module (CEM) also transmits the results of the key check to the engine control module (ECM). If the identity check between the engine control module (ECM) and the central electronic module (CEM) as well as the check on the key are OK, the engine control module (ECM) will transmit a command to the central electronic module (CEM) that the starter motor may be activated. The engine control module (ECM) will then also activate the ignition system.

Note! The engine control module (ECM) allows the starter motor to turn once the identity check between the engine control module (ECM) and the central electronic module (CEM) is complete. The starter motor will not be allowed to operate until the check on the ignition key is complete. Depending on the outcome of these two checks, the engine control module (ECM) will then determine whether the starter motor is to be allowed to operate.
If either of the checks fails, a message will appear in the display on the driver information module (DIM) and the engine will not start.Activation
The immobilizer system is activated when the ignition key is turned to position 0 and the engine stops. The engine control module (ECM) then sends a command to the central electronic module (CEM) that the starter motor is no longer permitted to turn.
The immobilizer system contains safety functions for preventing the system from being activated in the event the engine should stop while the ignition is still switched on. In this case the engine control module (ECM) will wait for a while before a command is sent to the central electronic module (CEM) indicating that the immobilizer is to be activated. If an attempt is made to start the vehicle within this time, there will be no new communication between the engine control module (ECM) and the central electronic module (CEM).
The immobilizer system will neither be activated if the vehicle is still moving when the engine stops. Similarly, the engine will not stop if the engine control module (ECM) conducts an internal restart while driving.
If the ignition key is turned to position 0 but the key is not removed from the ignition switch, the engine control module (ECM) will wait for a while but then send a command to the central electronic module (CEM) to activate the immobilizer, despite the fact that the key has not been removed from the ignition switch.

Error message in the Driver information module (DIM).
Two different error messages may be displayed in the Driver information module (DIM) display for the immobilizer function in the S80/S60/V70/XC70/XC90:

Note! Because the information is sensitive to change the exact wording cannot be written here.

1. Message regarding fault in the system for the immobilizer with reference to the user manual. The message is displayed when a problem has occurred in communication between the Central electronic module (CEM) and the Engine control module (ECM).
2. Message regarding prevented start with new attempt request. The message is displayed if a fault has occurred when reading the transponder in the key.

Note! There are rare cases of faults related to the immobiliser system that do not store any diagnostic trouble codes, no diagnostic trouble code appears in the Driver Information Module (DIM) either.
For further information, see Diagnostic trouble code (DTC) information for the relevant diagnostic trouble codes (DTCs) in the Information manager.

 

here's a really good comprehensive diagnosis tutorial for fuel pump issues

 

Thanks very much for digging all this information up. I stumbled upon this series of videos earlier today and it turns out the problem with my daughter's car is exactly what the Pine Hollow guy experienced. I verified everything he did including powering the fuel pump with a separate battery and it works fine. I took the cover off the PEM and it looked just as bad as his did so I ordered a replacement off ebay. I learned quite a bit about taking this car apart and can see why people like them although I'm glad I don't have to remove any more of the back seat! It looks pretty heavy, lol.

 

i have to take mine all the way out and drop my gas tank
then flush the whole system. lots of fun.
Let me know if you're all fixed up after the PEM

 

Will do - it will probably take a week or so to get it delivered but I will post up with a status report.

 

as an aside, make sure the cars been checked for the fuel pump recall and been serviced for the airbag recall

 

So this took a bit longer to resolve than I had hoped but ultimately the replacement PEM fixed the issue. I had ordered a used module on ebay but the seller was unresponsive (despite his 100% feedback) and after losing a week I got it refunded and bought another one. The car fired right up with the second PEM - so far, so good. Thanks for everyone's help.