New ZR-1 Owner, Data Streaming Questions - ZR-1 Net Registry Forums

zig · 08-11-2013

Finally got one of my dream cars. 91Z, red on red with 12,000 miles. I am trying to pull codes and view stream data with an AutoXray 7000 (OBD1, OBD2, ABS capable scanner). Have used it hundreds of times on my 91 Z28 (L98) with OBD1, a 96 Collector Edition (LT1) with OBD2 and a few other OBD1 and OBD2 cars. Never a problem with it and checked it again on the 91 Z28 today. When I use it on the ZR1, I get intermittent communication failures when retrieving codes and can never stream data. I compared the serial data output voltage to my Camaro and the ZR1 shows a little lower (4.5V vice 4.95V) but I don't think that should cause any problems. Car runs fine and I can pull codes and run all the diagnostics in the FSM with successful results. I did pop a Code 44 left O2 sensor lean yesterday which is what started me down this path. Probably a fuel pump or injectors?? I have done:

- measured resistance in all the ECM and CCM wires to the ALDL
- Checked all grounds from the ECM, CCM and ALDL to the battery ground cable
- measured the voltages on ALDL pin B (4.95V) and pin M (4.5V)
- Pinned out the xray 7000 OBD1 connector to make sure it's good

I would think if the CCM or ECM was bad I would be seing other issues when I run manual diagnostics. Am I missing something?

What do you guys use to view the data stream? I have thought about a Moates setup for the 91 Z28 for years but never pulled the trigger. The Xray 7000 was cheap and has been good unitl now.

08-11-2013	#1
zig Join Date: Jul 2013 Location: Ft Worth Posts: 50	New ZR-1 Owner, Data Streaming Questions Finally got one of my dream cars. 91Z, red on red with 12,000 miles. I am trying to pull codes and view stream data with an AutoXray 7000 (OBD1, OBD2, ABS capable scanner). Have used it hundreds of times on my 91 Z28 (L98) with OBD1, a 96 Collector Edition (LT1) with OBD2 and a few other OBD1 and OBD2 cars. Never a problem with it and checked it again on the 91 Z28 today. When I use it on the ZR1, I get intermittent communication failures when retrieving codes and can never stream data. I compared the serial data output voltage to my Camaro and the ZR1 shows a little lower (4.5V vice 4.95V) but I don't think that should cause any problems. Car runs fine and I can pull codes and run all the diagnostics in the FSM with successful results. I did pop a Code 44 left O2 sensor lean yesterday which is what started me down this path. Probably a fuel pump or injectors?? I have done: - measured resistance in all the ECM and CCM wires to the ALDL - Checked all grounds from the ECM, CCM and ALDL to the battery ground cable - measured the voltages on ALDL pin B (4.95V) and pin M (4.5V) - Pinned out the xray 7000 OBD1 connector to make sure it's good I would think if the CCM or ECM was bad I would be seing other issues when I run manual diagnostics. Am I missing something? What do you guys use to view the data stream? I have thought about a Moates setup for the 91 Z28 for years but never pulled the trigger. The Xray 7000 was cheap and has been good unitl now. Last edited by zig; 08-11-2013 at 10:01 PM. Reason: I understand it's an OBD1 car.