hello all, I have been working my way through a new to me 2001 v8. It's been quite a journey but were getting there.

I have a remaining set of issues that I suspect may be related;

- I occasionally get 3 pings (which I understand to be a code being set) after a few minutes of driving. It doesnt reoccur in that trip, and the SES light does not come on. I have a scanguage connected which shows no codes, nor does any other scanner I have tried (5 of them).
- less frequently (twice so far) I have had the SES light come on, but no codes are posted.
- i mentioned I have a scanguage connected, and it reads things like rpm, tps, load etc, but will not read coolant temp. I spent time with the(very helpful) guys at scanguage and we did several diagnostoc commands - the ECU replies that coolant temp is not supported. Not unavailable... not supported.

I have been through all the plugs for the modules in the passenger footwell, assuming Id find corroded connectors. They all look clean, I cleaned them anyway. The only oddity I found under there is a pair pf disconnected green wires, which a google search throws up as being very common, presumably some recall or late modification at the factory.

Has anyone had any experience with the symptoms above? It seems to me that some part of the control systems is not communicating correctly, butI dont want to start swapping parts without something to go on. The vehicle drives fine, no evident symptoms of malfunction outside of the pretending-to-throw-a-code behavior.

ideas?
Brian

 

Potentially an ECU malfunction? I would think no coolant temp would trigger a temp out of range code. Does the dash gauge work? This would indicate that the ECU is seeing the CTS, just not reporting it 100% correctly. Without coolant temp the mixture will not be properly modulated, which should also throw a code. In that you have multiple scenarios that should potentially trigger codes, but none are registering, I would swap an ECU to see what effect that has.

 

Mine does this occasionally too. I don't think the 3 pings necessarily mean that a code is being set. It never seems to cause any issues.
I do get the 3 amigos pop sometimes, so I wonder if the pings might be related to them somehow.

 

Hmmm... think the 3 pings are actually coming from the SLABS unit (air suspension, ABS brakes, Traction Control, Hill Descent Control) and not the engine ECU. I don't think engine ECU pings or beeps when a check engine code is set, does it ?(anyone know)

For your scan gauge issue, I'd just try something else (ultra gauge etc). Should not be tough to get the coolant temp reading via OBD port. If it is...then there's an issue somewhere.

 

I was thinking the same, along with fault T/C switches that could be signaling engagement or disengagement of Low/High.

 

I would concur that it's likely the SLABS. I never had it happen before I upgraded mine to the 2004 version.

 

Interesting, thanks folks

Clarification: my temp guage does work (i know because im chasing it moving up to 3/4 of the white under hard driving), and likely I will fit an additional more accurate/direct one.

interesting that SLABS is the likely cause of the pings, is there a way to debug/diagnose that and see what it has to say?

My understanding is that I cant simply replace the ECU and that I need to pair that with the BCM and guage cluster, or be prepared to find someone willing to do some reprogramming?