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

cocoli · Post by **cocoli** » 17 Jan 2018, 18:34

Hello everyone,

I need your advice.

2003 XC90 T6 w/ 10.5K miles, it has no click, no cranking, no start issue intermittently. Dash lights come out, AC not start, headlight is on for 1 seconds. No any alerts. Looks like no electric power supply to starter.

I have replaced started and battery, I also clean the small wire terminal between ignition to starter. O'reilly checked the alternator, it is good and battery is full. Battery cables are tight and very clean.

After replaced battery, it worked for half day and I drove for 30 mils. At night, I drove it to Costco to return old battery, when came out from store, could not start it again, tried jump start, not work. Sit inside car to call AAA for joining membership, when AAA asked for detail address, I tried it again, it suddenly started. So after 10 mins, I did not do anything, it worked again.

I suspect the problem is: wires connection, ignition switch, compute boards (ECU).

Any other hints/advice for this issue.

Thanks.

Susan

Post by **FLXC90** » 18 Jan 2018, 19:43

Check to see if this is symptomatic of Central Electronic Module (CEM) failure, otherwise I'd look at starter relay or electrical portion of ignition switch

Post by **RickHaleParker** » 18 Jan 2018, 20:59

We had something like this not to long ago. But the guy had trouble following instructions and never came back with answers.

If it happens again try a self jump start. Lift the small cover on the fuse box, there is a jump start post under it. To do a self jump start, you take the red lead of the jumper cables, hook one end on the positive terminal of the battery, connect the other end of the red lead on the jump start post. If it starts, it is the cable between the battery and the jump start post.

The cable may look good but they can develop problems under the insulation which cannot be seen. They are so long a little damage along the length adds up.

Post by **FLXC90** » 19 Jan 2018, 21:02

RHP- are you talking battery in the vehicle? It is trunk mounted. Or are you suggesting jumper battery to jump post and ground on engine? Or making a "jumper cable" like a jumper wire?

cocoli · Post by **cocoli** » 19 Jan 2018, 23:19

Hi,

Ok, I will try it next time, but it looks like not wire connection problem. This morning, I failed to start on first time, then tried second time immediately with push very hard of key, it started.

RickHaleParker wrote: ↑18 Jan 2018, 20:59 We had something like this not to long ago. But the guy had trouble following instructions and never came back with answers.

If it happens again try a self jump start. Lift the small cover on the fuse box, there is a jump start post under it. To do a self jump start, you take the red lead of the jumper cables, hook one end on the positive terminal of the battery, connect the other end of the red lead on the jump start post. If it starts, it is the cable between the battery and the jump start post.

The cable may look good but they can develop problems under the insulation which cannot be seen. They are so long a little damage along the length adds up.

cocoli · Post by **cocoli** » 19 Jan 2018, 23:19

FLXC90 wrote: ↑18 Jan 2018, 19:43 Check to see if this is symptomatic of Central Electronic Module (CEM) failure, otherwise I'd look at starter relay or electrical portion of ignition switch

Thanks, any idea on how to check central electronic module?

Post by **RickHaleParker** » 20 Jan 2018, 03:41

Or making a "jumper cable" like a jumper wire?

Use the jumper cables as jumper wires.

Post by **RickHaleParker** » 20 Jan 2018, 04:08

This morning, I failed to start on first time, then tried second time immediately with push very hard of key, it started.

No crank and no start are separate issues. However there are somethings that could be a common root cause to both. Ignition switch is one.

Before you go after the Ignition switch, what was your temperature this morning. The "push very hard" indicates the lock may be getting gummed up and cold weather is aggravating it.

Strattec Security's Lock Shot Lubricant might clear that problem, it a lot less work and hassle then going after the Ignition switch mechanics, worth a shot. https://www.ebay.com/itm/Strattec-Secur ... 2519670444

cocoli · Post by **cocoli** » 20 Jan 2018, 20:32

RickHaleParker wrote: ↑20 Jan 2018, 04:08 This morning, I failed to start on first time, then tried second time immediately with push very hard of key, it started.

No crank and no start are separate issues. However there are somethings that could be a common root cause to both. Ignition switch is one.

Before you go after the Ignition switch, what was your temperature this morning. The "push very hard" indicates the lock may be getting gummed up and cold weather is aggravating it.

Strattec Security's Lock Shot Lubricant might clear that problem, it a lot less work and hassle then going after the Ignition switch mechanics, worth a shot. https://www.ebay.com/itm/Strattec-Secur ... 2519670444

Hi,

I am on West coast, temperature is around 40-50F.

Today I planed to hiking, I could not start my car again at home driveway, I tried to use primary key first, it was failure. Tried to use backup key, still failure. Then I used jump wire to connect start relay pin #87 & #30, car was started. After hiking, I used backup key to start my car, it worked. Stopped at grocery store, used backup key again, worked.

Arrived at home, showed my friend (he is handy man, did lots of troubleshooting for his old Audi) the problem, started it with primary key, did not work. Switched over to backup key, still not work. I will try to use backup for next a couple of days to see I can start my car or not.

Cheers.

Post by **RickHaleParker** » 20 Jan 2018, 23:35

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.