Folks,
I'm seeing some issues/symptoms.

Mods on 02 Z w/31000 miles:
- 224/224 cam
- Stainless Works headers
- Shaner
- Vortex airbox

Problem:
I'm wondering if the "10 PCM 02 Sensor" codes described below are triggering the "60 IPC Loss of PCM/DCM/IPC Communication" codes below.

Symptoms:
-- Last couple of weeks at least... some times burning smell on start up, and then tonight, buring smell returned briefly for 30 sec or so. Had local quickie lube change oil two weeks ago, w/my oil and filter... Can't remember precisely if I smelled this previous to oil change.
-- 8-10 codes over the past couple of 2-4 weeks, the 10 PCM codes
-- The "60 IPC" codes have never appeared w/o the "10 PCM" codes

Circumstances:
-- AC has been on in all instances.
-- I've had Stainless Work headers on for the past year and I'm using 02 sims in the back two slots on the headers. Was not seeing any codes until the last 3 months or so.
-- I drive the car 2-3 times a week: airport and back, then maybe to block buster.
-- Outside temps ranging from 77 to 102
-- Ran HPTuner scan/log on the car for 60 min and saw nothing unusual. I did not get any codes during this time.
-- The "10 PCM" codes some time on start up, usually if I romp on it, some times not all.

Codes:
10 PCM HC (Heated O2 Sensor--heater circuit banks 1 and 2, Sensor 2-B)
P0161
P0141 (Get this one WAY less often... 2 time in last 3 month)
60-IPC H C (Communication Loss errors-- PCM, DCM, and IPC)
U1016
U1064
U1040
U1176
U1088
80 Radio H C (Communication Loss errors-- PCM, DCM, and IPC)
U1096
U1064
U1016
28TCS (on start up, only. Maybe 2 in last month)
Service system
ABS warm up

Thanks in advance for any help.
Doug

 

I'm willing to bet your battery is getting weak.

 

P0141 and P0161 are usually bad O2 sensors or sims in your case. O2 sensor codes can also occur if the harness is damaged.

The 'U' codes often are triggered for some reason when you throw other codes and can be ignored if they can be reset.

Can't tell you anything about the 28TCS related codes as you did not post them

 

The U 1000 series codes indicate that you have a battery issue. The reserve capacity of your battery is low. When you turn the key and the starter kicks in, it draws 250-300 amps. Battery voltage is inversly proportional to current, in that the battery voltage will go low whrn current goes high. If your battery is weak, it will allow the voltage available to all of your computers (PCM, BCM, LDCM, RDCM, SDM, SCM, ect ect ) to drop below 9 VDC for a fraction of a second. As soon as the engine starts the voltage returns to normal the codes go to History!

I would drop a new battery in and that may solve a lot of your issues.

Bill C

 

Fix the other codes and the U codes will most likely go away.

 

Fix the other codes and reset and the 'U' codes will most likely not return

 

That is absolutely not true, why would faulty O2 sensors cause communication problems between the modules

 

From the service manual for all 'u' codes under diagnostic aids: "Communication DTCs do not necessarily indicate a malfunction. These DTCs are only intended as an aid in diagnosing an intermittent communication malfunction that is accompanied by a symtom. If the vehicle does not experience a symtom related to a communication malfunction, these DTCs can be disregarded."

 

Take it from LOT's of EXPIERENCE!!! For the most part U series codes resulting from weak or defective batteriees is VERY common!!

""Communication DTCs do not necessarily indicate a malfunction. These DTCs are only intended as an aid in diagnosing an intermittent communication malfunction that is accompanied by a symtom."

Loss of power or power droping below the cut off voltage of the module is a malfunction and a symptom of a bad battery.

Hell,, my 02 Z06 started getting U codes for the SCM while it as under warrenty. Took it in and the dealer had to replace the Seat Control Module. It was having intermittant comms problems from the module it self.

It just a suggestion and a troubleshotting aid. When I get frequent U codes, I always check the condition of the battery and electical system (i.e. battery cables, grounds, and battery charge state.)

Yes you can get random U codes and I just reset them. If you get U codes that set history codes immediately after you start the car, my bet is the battery is the cause.

Just my 2 cents.

Bill C

 

Hey Guys,
I have not responded as I have been out of town. Thanks for all the replies.

I replaced the battery, last Monday, and did not get a chance to drive it until today. Good news: not communication codes popped. Bad news: Still getting the 02 codes from my 02 sims. I'm going to try disabling the codes and getting the car into the air this weekend to check wiring and such.

will keep you posted.

Thanks,
Doug

 

I was under the impression the "LOSS OF COMMUNICATION" is,was a common problem to these cars. I to have had these issues but not near as many as you have. Bill has helped many here. My tuner would not install my full tune because of the lack of logging that had appeared on a few runs. Still need to get it done. I too just reset the codes and I am good for quite a while.
Matt

 

Yes and no

I get an occasional loss of communication between the radio and maybe one of the door modules but when you get the loss of communication to the PCM or BCM and especially when you get as many as DrMitchell then it's time to start trying to figure out why and most times it's a weak battery or a bad ground causing the voltage to dip during starting that cause the module to show a loss of comm.