OBD II scanner has no connection to data port

DIESEL357

MEMBER
2010 NISSAN SENTRA
2.0L
4 CYL
2WD
AUTOMATIC
102,548 MILES

This is for the car listed above automatic transaxle 4 door vehicle without turbo.

{OBD II scanner has no connection to data port}

First,
OBD II scanner not reading or connecting to data port under dash to pull codes. All fuses are okay under the driver's dash and under the hood. Battery is reading 11.74 volts, starter cranks but engine not engaging after finding out a burnt wire to the starter shunt was bad (it has been replaced and power is flowing to that wire).

Now,
the A/C fans constantly run while ignition is in the "on position". Crankshaft and Throttle position sensors have been replaced; all warning lights on the dashboard comes on with the following :
(1)Service engine soon light,
(2) PS red warning light is on
(3) Temperature gauge stuck at "c" not in between Hot/Cold ; which tells me the customer ran out of coolant at some point. While, continuous driving and tried to fill it up after the car overheated or began jerking after adding gas. Which could possibly blown the fuel pump and other stuff.
Note: tried ether starting fluid to the MAF sensor(same results; crank but not starting. Disconnected the fuel rail line and fuel is running back to the fuel pump with line at the fuel pump being disconnected. Starting to hear metal on metal (which tells me the timing is off or the firing order 1-3-2-4 is offset; timing belt could be off track or slipped as well. But haven't went into further detail until OBD II/III scan tool can connect first).
(4) Upper bank 02 sensors are dirty
(5) Spark plugs has been replaced along with ignition coils
(6) Customer had oil changed recently _about 2 months ago_
(7) Valve cover gasket is fine from a visual inspection after removing the cover
(8) Crankcase housing smells burnt of oil and sludge build-up; Camshaft lob is super hard to move manually
(9) Head gasket seems to be burnt/warped after a loud misfire (engine was immediately shut-down to prevent further damage and cause of fire, harm or injury).

What other steps can be taken to rectify the issue to get the vehicle at least reading the OBD II/III scanner or just the vehicle to stay cranked at normal operating temperature and speed? Thanks.

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

I don't think we are going to solve any of these issues until we figure out the scan tool issue. If you are plugging in the scanner and it is not connecting to the PCM then that is a communication network issue.

So we need to check voltage at the DLC and make sure it is correct.

Basically the CAN network is a communication network that the modules use to communicate with each other.

Here is a guide that will help with this:

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Once we know what the voltage is on these two wires we will have a better idea as to what the issue could be.

So use this guide to help with checking voltage on both pins 6 and 14 to ground. So that means 6 and ground. Then 14 and ground with the key in the run position.

https://www.2carpros.com/articles/how-to-check-wiring

Below you will find the wiring diagram that will show the circuits that we need to find out what the voltage is.

Then has this scanner every connected to this vehicle and communicated with the PCM before? If not, then the vehicle may be fine and this could be a scan tool not being compatible with the vehicle.

Let's start with this and go from there.

Thanks

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