Ob2 port won't read codes, personal reader and store reader - 99 s70 na Topic is solved

[smacknab]

Check the voltage from 16 to a chassis ground to see if pin 16 has battery voltage

Pin 16 to the frame near the driver's side door hinge read about 2 mV

I'll check the under dash fuses when it stops hailing, but thanks to everyone for chiming in. To be honest it's a little over my head at the moment but I'll check the fuses soon and report back what I find

[abscate]

If I plug an OBD READERinto a 1999 am I reading on the K line or CAN BUS?

Will it depend on the protocol of the scanner, perhaps?

[smacknab]

Someone suggested I check that it's plugged in, looks good to me.

Still waiting for dry weather to check the lower fuses

[jimmy57]

K line is what Generic readers use. K line is used by VIDA (and some others I suppose) to tell the CDM (inst cluster) to open the gateway and connect high speed CAN wires.
If the scan tool came on, display was on, but wouldn't communicate then K line issue is likely. If the tool did not come on then the pin 16 wire or ground is suspect.

[smacknab]

K line is what Generic readers use. K line is used by VIDA (and some others I suppose) to tell the CDM (inst cluster) to open the gateway and connect high speed CAN wires.
If the scan tool came on, display was on, but wouldn't communicate then K line issue is likely. If the tool did not come on then the pin 16 wire or ground is suspect.

No display came on. I'm going to get some contact spray and try that. When you say ground, does that mean any ground in the car? I did just take the head off and reassemble the car, so possibly i missed a ground wire in the engine bay on reassembly?

[abscate]

You’ve got no voltage on pin 16 on the OBD

Start tracing backwards from that pin to see where you lose the 12 volts

That’s the systematic approach

[RickHaleParker]

11A/6 & 11C/5 fuses under hood.

24/2A Connector Green 12-pin (male- female)
Engine compartment cable harness - Firewall cable harness

24/7B Connector Natural10-pin (male- female)
Firewall cable harness- Tunnel cable harness

EM2.png

[smacknab]

Found it! Fuse 11c/5 was blown. Ob2 is scanning again. Thanks everyone for the hand holding, I didn't know that the fuses had different designations based on their location!

[abscate]

Excellent. There is one weakness with the incredibly well-done Volvo wiring diagrams

Sometimes, you want to know everything that is on a circuit so you can figure out what is making the fuse blow.

1 You can famously RTFM and read the fuse systems in the manual (Volvo manuals are all online for free)

2 You can look at the back of the fuse and color/mechanically trace the wire

3 You can hunt through all the wiring diagrams and look for references to the (example above 11C/5) fuse designation.

SM - for the 11C/5 I think this circuit feeds:

Engine cooling fan
ECC climate control
MCC climate control
Diagnostics

so if it blows again, that's the list of things to check

[RickHaleParker]

11C/5

• Engine cooling fan (FC)
  Diagnostics (OBD pin #16)
  Standard heater
  Manual climate control (MCC)
  Electronic climate control (ECC)