2003 XC90 T6 won't start intermittently w/ new starter & battery

[cocoli]

Your Immobilizer Antenna maybe on the fritz. It may not be reading the key security codes reliably.
You might try holding the plastic part of one key right next to the antenna ring as you turn with the other key.

Today, I measure the voltage on ignition switch output Y-W cable, which is connected to CEM, it is 14.2v when starting (failure). Then I measure two control sports for starter relay, one is always 0, one is sometime 14.2v, most of time is 0.

See attachment wiring diagram of 2003 xc90 starter. Sounds CEM has problem.

[RickHaleParker]

IF 1(86) does not follow 3/31 pin 7 religiously. You got an intermittent open in 15/31, C14:6, GN-R or 54/3LC.

Place the positive lead of the voltmeter at 3/31 pin 7, the negative lead at 1(86). Crank, the voltage should be 0V if it jumps to 14.2V you got a intermittent open.

Most probable cause is the junction of Electrical distribution 15/31 and Connector C14:6.

[cocoli]

I did check based on xc90 wiring document, ignition switch is fine (output voltage is 14.2), but fuse box Gn-R voltage is 0, sounds CEM or ECM problem.

Can Vida Disc reset/reload CEM ? If yes, I would like to pay $60 on ebay to get it.

[RickHaleParker]

There is more then one Gn-R at the fuse box. One going to the starter relay from the CEM and one from the starter relay to the starter.

Pull the starter relay at the fuse box. Clean the connections. If that does not work, swap the starter relay with one of the others that is the same. This might disable another circuit but it can tell you the starter relay is bad.

Vida-DiCE is always a good investment if your going to do any of your own work.

[cocoli]

There is more then one Gn-R at the fuse box. One going to the starter relay from the CEM and one from the starter relay to the starter.

Pull the starter relay at the fuse box. Clean the connections. If that does not work, swap the starter relay with one of the others that is the same. This might disable another circuit but it can tell you the starter relay is bad.

Vida-DiCE is always a good investment if your going to do any of your own work.

Starter relay is good and clean. Today I removed the CEM, it looks good, no corrosion on board, only little bit corrosion on relays, I cleaned the relays and put them back.

I borrowed Vida dice 2014A, I did not find any alarms/alerts of CEM. I am disappointed that it has not calibrate CCM function, only pragramming CCM option, and it does not really calibration.

The Volvo gave me too much trouble, and I decided to sell or trade in it, so I don't want to invest money on it, only need to fix start failure issue.

Regards.

[cocoli]

It is weird , I installed 2014D today, but I still have not see CCM calibration option. From youtube, I saw other people have 6 options on 'Advance' tab, but I only have 4. Is it normal for 2003 XC90?