1999 v70xc P1550 won't start

ajr2820 · Post by **ajr2820** » 20 Jul 2015, 18:03

I gave my stepson my 99 V70XC a couple of months ago. Today, he said the motor started shaking and it quit on him. I could get it to run for 5 seconds at best and there is a vibration. The only code was a Volvo specific P1550. This is an ABS code, so I'm unsure how this relates to the no-start condition. Any ideas? Unrelated or not? Simply looking for suggestions on a place to start. As an aside, the ABS and traction control lights had intermittently come on and gone away last September when the car was still my daily ride, but it never adversely affected my travels.

Post by **Ozark Lee** » 20 Jul 2015, 19:37

The P1550 is specifically a speed sensor code but you are correct in that it points to the ABS module since that is where the speed sensor signal is generated. It can cause the car to run bad and the transmission to act up but, as you indicated, it will not cause the car to not start and run.

Have you checked the fuel pressure?

Low or no fuel pressure won't set a code but it will keep the car from running.

...Lee

ajr2820 · Post by **ajr2820** » 21 Jul 2015, 05:10

Thanks. I thought as much. Just wanted to be sure. It's in a parking lot where he works. Didn't have my pressure gage with me. Fuel pressure was going to be the first thing I looked at.

ajr2820 · Post by **ajr2820** » 21 Jul 2015, 16:47

OK. So I got her started. Ran real rough. Stalled a couple of times and was hard to start back up. In park, the engine stumbles before gaining RPMs, then it holds the RPMs and has a very slight shudder. Tried disconnecting the MAF and it immediately stalled. It then took a few tries and I got it to start with the MAF disconnected, but it acted the same. Reconnected the MAF while running and it made no difference. It threw a code while the MAF was disconnected (probably the MAF code, but being away from home I did not have my scanner). Having my rollback from work drag her to the house in the morning so I can work on her at home. Also, I hear an intermittent, brief, but regular hiss when the engine runs. Seems to be coming from the back of the engine i.e near the firewall. Does all this sound like head gasket issues? No oil in the coolant or coolant in the oil. Any ideas on where to start?

Post by **FLXC90** » 21 Jul 2015, 16:56

check all the air lines to and from turbo first. Unregulated air will confuse computer. Doesn't sound like HG to me. Need leakdown or similar tests for that diagnosis though.

ajr2820 · Post by **ajr2820** » 22 Jul 2015, 05:22

Thanks. I'll check that first.

ajr2820 · Post by **ajr2820** » 22 Jul 2015, 16:06

I finally got the car home. Now there is a P0302 code. Went to swap #1 & #2 coils to see if it was simply the coil. No dice. In fact #2 plug well was filled with oil. I guess the kid can't put a quart in without spilling 1/2 a qt. The former #2 coil worked perfectly in the #1 slot. So, I'm kinda stumped as to where to look next. What would cause this? I checked the wiring leading to the coil.All looks fine.

ajr2820 · Post by **ajr2820** » 22 Jul 2015, 16:33

Nevermind...I went back to the basics. Got out the compression gage...#2 has zero compression!! How difficult is it to yank the heads of these things?

Post by **abscate** » 21 Oct 2015, 08:07

Just adding to this thread

My 1999 through this code which my AUTEL reports as Boost Pressure Variance or something like that.

Given I just worked on my right front WB and my ABS light is on (And the AUTEL reports that the right front ABS sensor isn't present) I call AUTEL SOFTWARE fail.

Post by **Ozark Lee** » 21 Oct 2015, 16:24

ajr2820 wrote:Nevermind...I went back to the basics. Got out the compression gage...#2 has zero compression!! How difficult is it to yank the heads of these things?

It is doable by mere mortals. The Tracy's True Soaps guide is pretty much the gold standard and your process will be identical with a bit more work to replace the burned valve(s).

Volvo 5-cylinder: How to Replace the Head Gasket

...Lee