Good day Volvo Forum members,

I am new to this forum, and have an issue with my 2004 Volvo XC90 2.5. It cranks but does not start. Here are the details:

• Took it to the Volvo Dealership and was diagnosed for a Catalytic Converter, O2 Sensors, Camshaft Position Sensor, and Crankshaft Position Sensor
• Got those replaced at a local mechanic (minus the O2 Sensors as the mechanic cleaned them and said they were okay)
• Was able to start the vehicle and drive it home
• Took it back for an oil change since it looked dark
• Drove it back home
• Now it will not start
• Check Engine light blinks
• Oil Pressure light turns on

Additionally:

• The battery is new
• The alternator is about 1 1/2 years old
• I am not sure about the fuel pump

My thoughts:

• Maybe the alternator has gone bad early? (I could not test it yet without pulling it or towing it to a shop)
• I had water in the driver side floor board, and maybe it is affecting the CEM? (I pulled the CEM and found no corrosion)
• Maybe I am having random ECM issues?

Any thoughts or insight on this would be much appreciated.

 

start by rechecking for CEL codes - I assume they were cleared after the new parts were thrown in. If the car cranks then you don't have a battery issue and probably not an alternator issue. A quick check with a volt meter can confirm - 12.6 to 12.8 V across the battery terminals with engine off is typical, 14V+ when the engine running. I think looking in the CEM is a good next step - a full feature scan tool (like the VIDA/DICE set up dealers use) can test/diagnose CEM vs ECM issues. As to the oil pressure light - that is just saying the light works :-) you won't register pressure until the engine starts up and gets to a steady idle, but this may also be an indication of an electrical issue so check fuses/relays as well.

 

Thank you for this quick reply, and for breaking this down. I will be sure to look into those items. I am also leaning toward a fuel pump, as I have seen others with similar situations who fixed them with a fuel pump swap. I will update this thread with any progress that is made.

 

As an update:

• I removed the CEM
• I noticed a little bit of corrosion, mainly at the bottom behind and on two of the relays
• I also noticed some corrosion on the part that is plugged in directly behind the 10mm nut/bolt
• The sunroof drain hose leaked for months during last year's rains resulting in water above the carpet. (It has all been vacuumed out and the Drain Hose Valve has now been replaced)

My questions:

• Based on anyone's experience, has the CEM been affected heavily requiring replacement by XeMODex?

Here are a few images below with captions below them:


Some corrosion in the CEM Relay area (technically at the bottom where the fuel pump relay goes)


Some minor corrosion on the connector near the 10mm nut/bolt.


Some visible corrosion on the relays (One of the two on the right was in the fuel pump relay plug.)

Below is a photo of the Sunroof Drain Hose with the new valve added on:


The sunroof drain hose valve was previously broken, causing inches of water to build up in the floorboard and above the carpet.