1999 V70XC 160k miles Similar to safe mode?

[Frogerelli]

I have had three incidents within the past week. I don't believe the first is related to the later two.

This is a vehicle that my daughter drives. Last week, it began running roughly and check engine light came on. Took it to auto parts store to use OBD II. Code 303, generic misfire, 3rd cylinder. Came home, looked on MVS, went back to auto parts store, bought and installed new coil for 3rd cylinder. Ran fine for the weekend. Monday afternoon, another call from daughter. Car barely moved, fortunately only about 1/4 mile from destination. I went to check it out. Engine fired, but ran in what seemed to be Safe Mode: barely 1000 rpm, ABS, traction control, and SRS lights illuminated. Couldn't make it back up slight hill to where it had been parked. Tried to start car, no juice. Pulled battery, back to auto parts store. Determined bad battery. New battery, installed and good to go. No lights, ran normally. This afternoon, daughter called again, saying same symptoms. Had to park the car on the side of the road. Friend picked her up. I got there about an hour later, car started fine and ran normally for about 1/3 mile then began hesitating and then into "safe mode" type behavior. Car tiptoed back to where my other car was parked. Tried to start car, no juice. Will go back later to see if battery has regained strength.

Thoughts? No light from alternator saying there is a problem. Alternator was replaced about 2 years ago with one from salvage yard.

[jblackburn]

This sounds like the positive battery cable to the fuse box near the windshield has gone bad. As it heats up, it will slowly choke off current flow and the car's electrical systems will start shutting down. You may also want to check the alternator to battery cable as well.

There are some Torx screws around the edges to the fuse panel; remove those and have a look inside to see if the connector is all corroded up. If there's no visible corrosion there or at the battery terminal connector, I would look into changing that cable altogether.

[osman]

Could be fuel relay as well or even ETM or PNP sensor. You need to determine whether spark or fuel are present when the car will not run.

[precopster]

Most likely culprit here is electrical supply interruption such as battery cable as jblackburn states. The 99 model uses the same ignition switch as earlier 850s and these were very troublesome especially with the later Canbus cars.

They changed the switch in the 2000 MY due to this.