OBD Scanners Cannot Establish Communication Link

I have a 2001 DC and got a CEL about a week ago. I took my truck to Autozone and they couldn't establish a comm link with two of their scanners. The OBD port powers the scanner on, but it searches forever then times out. I then brought it over to Advanced Auto Parts, their scanner had the same issue. I own a BAFX OBDII scanner myself, same issue. Lights on the scanner turn on, Torque cannot establish a link.

I've checked the OBD 7.5amp and EFI 20amp fuses, both appear okay and have continuity. I was getting 12.54V on Pin 16 with the key turned to 'On' and with the key out. I was getting 8.something V on Pin 7 with the key turn to 'On' and nothing with it out. I'm getting audible continuity on pins 4 and 5 although the reading started at 4ohms and settled at 0.0 (continues to make noise at 0.0). Cigar lighter and AUX ports are all working fine.

The truck was inspected in MA last October so I have to assume it was working at that time. The only change I've made since then is replacing the factory radio with a single din JVC with a wiring harness. The JVC was spliced to the harness, no factory wires were touched.

I'm at my wits end here, anything else I can check before taking it to a shop? Thanks!

 

there is a thread on the 2nd gen forum with exactly your issue but with no resolution. In this thread he mentions that one shop WAS able to get it to communicate, was this BS just to make him go away, dont know. If it were me I would disconnecct the battery for 10 minutes then one by one unplug the connectors from the PCM and slide them back on reconnect the battery and recheck. This other thread mentions that the dealer said that there is a possibility of the aftermarket radios power being tapped off of a power feed to the PCM... seems far fetched to me but I was not there to witness it.

I do not know what the difference is between the DLC (data link connector) that is on the motor and the OBDII plug in the cab.

 

Disconnected the fuse the radio uses, no improvement. Can you jump the E1 and TE1 pins in the DLC diagnostic box for this generation? Unhooking the battery for 15 mins cleared the CEL, would I have to wait for it to come back on to try jumping the pins? I'm assuming the code was cleared when I disconnected the battery.

 

We have a very expensive scanner at the body shop I work in. I have an ABS light on and our scanner won't read it. I called the company who we got the scanner from and they let me know that there is a process to use some jumper leads and a test light to find out what the issue is. I'm not going to get into all that mess so I just plan on taking it to the stealership eventually.
The problem is the software in the truck, not the scanner.

 

Might just be dirt or corrosion on the vehicle side.

I have this happen all the time I venture from new there is a cover that was long gone till I got my Truck.

Go with the simple first.

 

Brought it into Toyota after exhausting what I had available to me. They said the ECU isn't salvageable and will need to be replaced. I'll be looking to find a used ECU, swap it out and hope the OBD port works then. Thanks for the suggestions guys!

 

get the part number off yours and reply i have a PCM out of one of my JDM motor swaps... might be japan only PCM but it it worth a shot.

 

89661-04821

 

at lunch atm, will check when I get home.


Mine 89661-26700... Maybe someone can see what mine came out of for a cross reference.

I re googled mine ... GRANVIA/GRAND HIACE looks like a Japan only Van PCM.

 

Did you figure it out.

My scanguage gives me all the correct info but the OBDII will not make connection with the Toyota dealership gauge, that makes no sense to me.