• Background:
  1999 Volvo S70 2.4L (Non Turbo) 137K (bought used at 48K 2003) Generally reliable for yrs, expensive last year and a half. Seen the old ChkEng Light too much, too many trips to Dealer. Never sure whether I am getting honest info. Never sure the Dealer really knows what they are doing, or actually did work billed, since several problems reoccurred. Bought OBD2 device to read codes (DTC's) on my PC.

TWO WEEKS AGO
Car runs fine but ChkEng Light comes on. OBD2 DTC's = (8)
P1057 (Not sure? - Possible TCM Fault- Possibly involving Throttle Module - opinions & sources vary)
P1081 (Immobilizer Communication?),
P0600 (Serial Communication Link Malfunction),
P0722 (Transmission Speed Sensor Missing or Output Speed Sensor Circuit -No Signal),
P0562 (Low voltage)
P1021 (???????)
P1025 (???????)
P1054 (Speed Signal)

I erase all codes and turn off ChkEng Light with OBD2 device & computer.


YESTERDAY (10-12 miles later)
ChkEng Light come on again. I hook up OBD2 device and PC to car to read codes and monitor and record vehicle operation and sensor data while driving. OBD2 DTC's = (4) The same four DTC's as before.
P0600 (reported by sensor # 122)
P1057 (reported by sensor # 122)
P1081 (reported by Sensor # 122)
P0722 (reported by sensor # 31)
DTC's are reported in the order listed.
See definitions of DTC's above - (as far as I can determine definitions)
A minute or two later, the (lighted) upward pointing ARROW starts flashing continuously in the instrument panel window where the ChkEng Light and other warning lights are located. Car still in PARK. (This lighted arrow usually only appears when the vehicle is in a gear below D, and then it stays on {not flasing} until the shifter is moved up to D. Engine still ran smooth, so I took the car for a short drive hooked up to the computer, and recorded operational data.
A mile or two later, while on the highway, the ABS and BRAKE lights came on then turned off, and repeated this cycle intermittently throughout the drive. The speedometer also stopped working (or dropped to zero while driving 60MPH) and the odometer reading turned into a line of dashes, then both came back on, and repeated a cycle of intermittent malfunction throughout the drive. Please NOTE, the vehicle continued to operate normally and the brakes worked fine.
SO NOW WHAT SHOULD I DO?
I won't be fixing it myself, but I hate to take it to the dealer for another expensive round of repairs that may, or may not, all be necessary and may, or may not, actually fix the car.
I have an honest local mechanic with some, but not lots of diagnostic equipment. He will competently do what I ask him to do, but it is better to know what work needs to be done or parts replaced. Then he will do what I asked for a fair price.
Any constructive advice or suggested solutions would be appreciated, hopefully from guys (or women) who know what they are talking about.
Thanks.

 

I solve all this problems replacing ABS module. Thank's.....

 

Wow, nice. Sorry no one here had an answer for you. Was your ABS light on?

 

Dear SRPI, yes the ABS light was on.
Now I have hesitated situation, probably is the fuel filter???? RPM goes up and down. What do you think??? There is a pending code P 1021, P 1025; but there is no light going on the dash, like a “check engine” I really don’t know about those codes????

 

I have similar problems with volvo s70 1999 FWD as fernan942.
I read many blogs trying to ind solution. Finnally could find that the issue is die to Immobilizer antenna ring not sending signals properly. Replacing the antenna ring will solve the problem. I will be doiing the same in next coming couples of days and will let you knwo if that fixed the problem.

 

Could be ABS, but you might have a weak battery also. Do the Hard Battery Reset. and go from their.