'97 Eagle Talon - No Communication, SES won't Light

[deadFRED]

Trying to help one of the students in my high school auto tech class get a '97 Eagle Talon 2.0L running right.

Little back ground:
Vehicle came into shop with second computer on passenger seat.
Has instrument cluster with factory turbo gauge (don't believe this is normal for a N.A. 2.0L)

The main issue I am trying to address with him is the no communication issue with the scan tool. The check engine light does not light up when key is turned on either. We checked pins 4, 5, and 16 for on the OBD II DLC. Pin 4 had 0.1ohms, Pin 5 had 0.1ohms, and Pin 16 had 12.16V so they all checked out.

Not sure what to check on the OBD I DLC (has both connectors right next to each other) requires Mitsu-1 splitter to connect to our Snap-On Verus scan tool.

Vehicle seems to be running fine minus running rich (missing air box and suspect other vacuum leaks we will have to address once we can monitor STFT).

 

[Diamond Star Werks]

Use the obdII split mitsu connector or a generic scanner. If it's non turbo the gauge isn't the same. You need to swap for a non'turbo gauge cluster to have all the lights work properly. The obdII is powered by the cigar fuse(cig light). Non turbo runs off the map sensor. Having no intake pipe won't affect the way it runs much. You need to check the fuel trims when you get communication. If it has a vacuum leak that will make it run lean not rich.

 

[asexton6969]

If you have an oscilloscope, check pin #14 at the DLC. See if it is shorted to ground or to voltage. If you don't have an oscilloscope, disconnect the instrument cluster and see if BUS functionality returns. Report back.

 

[deadFRED]

Use the obdII split mitsu connector or a generic scanner. If it's non turbo the gauge isn't the same. You need to swap for a non'turbo gauge cluster to have all the lights work properly. The obdII is powered by the cigar fuse(cig light). Non turbo runs off the map sensor. Having no intake pipe won't affect the way it runs much. You need to check the fuel trims when you get communication. If it has a vacuum leak that will make it run lean not rich.

Was referring to it smelling rich. I understand that un-metered air causes a lean condition which in turn causes the ECM to increase fuel.

 

[deadFRED]

If you have an oscilloscope, check pin #14 at the DLC. See if it is shorted to ground or to voltage. If you don't have an oscilloscope, disconnect the instrument cluster and see if BUS functionality returns. Report back.

Awesome! This was the type of pointer I was looking for! Will report back tomorrow.

 

[deadFRED]

If you have an oscilloscope, check pin #14 at the DLC. See if it is shorted to ground or to voltage. If you don't have an oscilloscope, disconnect the instrument cluster and see if BUS functionality returns. Report back.

Pin 14 on the DLC spiked to 5V when key was turned on but immediately fell to 0.14V and stayed there. Disconnecting the instrument cluster had no affect on BUS functionality or scope readings.

 

[asexton6969]

Ok, I double checked the wiring diagram and looks like I read it incorrectly. My apologies, at the DLC check pin #7 (pink) for communication. Then on the Mitsu connector check pin #5 (DB/BK) for communication as well. These are the SCI transmit and receive wires. I could certainly see the instrument cluster causing an issue but I have seen plenty of PCM's go out as well. Should have 5 volts at key on and start pulsing when communicating.

P.S. sorry for the late response..

 

[deadFRED]

Ok, I double checked the wiring diagram and looks like I read it incorrectly. My apologies, at the DLC check pin #7 (pink) for communication. Then on the Mitsu connector check pin #5 (DB/BK) for communication as well. These are the SCI transmit and receive wires. I could certainly see the instrument cluster causing an issue but I have seen plenty of PCM's go out as well. Should have 5 volts at key on and start pulsing when communicating.

P.S. sorry for the late response..

No problem appreciate you getting back at all. Students are on Christmas break but will be sure to have the student check those values when we get back.