Yes to both. Will open it back up but do you now which wires specifically am I looking at?
And thanks again for all the responses.

 

OK, first let’s do a voltage drop check across the 2 PCM fuses…fuse 16 and fuse 23 (PCM B)…PCM B also is the 12 volt feed for the cam and crank sensor…connect positive lead of DVOM to battery positive and with negative lead touch it to one of the 2 fuse test points on top of the fuse to fuse 23…hot at all times so it comes from the battery…should read zero…now turn the ignition switch to on or crank the engine (preferred) and do the same of fuse 16..we are just checking for voltage drop across ignition switch…if voltage drop let’s say reads 4 volts that means out of 12 volts only 8 are going to that component !!…if both good you need to access the PCM to check voltage there…pins 20 and 57 on the C1 connector gets power from fuse 23 (PCM B)…see if you have system voltage at those 2 pins…now check pin 19 on the C1 connector (pink wire)…should be hot in on or start…I like cranking the engine over to verify making sure voltage is good and not dropping.

Now for grounds: on C1
pin1 and pin 40 (black/white)

On C2
pins 40 (black/white)

You will need a back probe or something like a safety pin to push up into the pin to check the power and grounds…you can use a 12 volt test light connected to battery positive to check the grounds !!…PCM are numbered 1-20, 21-40, 41-60 and 61-80 !!

 

Just the first test - ignition OFF - no voltage from battery to 23. Then ignition ON, voltage ONLY .04 on fuse 16 test points.
Need friend, tomorrow, to test cranking engine.

 

Can you check fuse 23 (hot at all times) with just the voltmeter and see how many volts you have...0.1 or 0.2 are good numbers for the “switched” ignition circuit…did you mean fuse 16 and not 23 ??..also what does your battery voltage drop down to during starting ??…just hook up DVOM to battery terminals and read it if you can ??..record before starting and during starting voltage.

 

Fuse 23 shows .01.
Fuse 16 shows 12v off, .04 on, .07-.08 when cranking, and .28 when running.
Wires on connectors:
C1 - 20 & 57 have 12v; 19 has 12v when on

C1 - 1 & 40 are grounded
C2 - 40 is grounded

FYI - PCM connectors are numbered "reverse" of the diagram in that 1-20 and 21-40 are on the top. Wiring is as you laid out.

 

Off battery at 12.3v, drops to as low as 11v for split second during start.
Immediately charges to 14v after starting.

 

OK, so that’s not an issue !!…power and grounds look good…can you just check again fuse 23 just to make sure there is good battery voltage there ??…when I reread my testing to you I realized that you can’t do a voltage drop on a circuit that is hot at all times…you have to remember there is “no voltage drop if there is no current flow”…rookie mistake on my end !!..can you clear the codes turn the key off now just turn the key on without starting…let’s see what codes it is setting with just the key on.Could you remove the MAF connector and with key on see if there is 5 volts on the yellow wire…I’m grasping for straws here and running out of ideas…LOL !!…for future testing get yourself some DVOM leads that have 4mm banana jacks on the end…and get yourself some back probes !!

 

Threads like this are Awesome. SOLID advice is being given and it is only a matter of time before this individuals car is fixed.

 

When u get the right surgent things get done right.

 

Ignition off fuse 23 shows 0.
With ignition on, shows .01 and .02 on the test points.

 

Can you just do a voltage check on fuse 23 and NOT a voltage drop !!…black lead on negative battery and red lead on both fuse test points.

 

Getting full voltage at fuse 23 test points.

Using Harbor Freight's best scantool Zurich ZR15 with latest firmware and database.
Eror codes - erased, scanned, erased, re-scanned - different codes(???)

101 108 117 118 125 131 132 133 134 135 137 138 140 141 151 152 153 154 155 157 158 160 161 171 172 174 175 200 230
300 325 327 331 332 335 336 341 342 343 410 412

101 108 112 113 117 118 125 131 132 133 134 135 137 138 140 141 151 152 153 154 155 157 158 160 161 171 172 174 175 200 230 231
325 327 332 335 336 341 342 343

Ignition ON, MAF yellow wire showing 5V.

 

which DTC’s ????…all of these ??..is it the first group or 2nd group ??…I’ve never seen these many before ??..and they are all current codes ??

 

Nothing shows current in DIC.

These are all red "P0XXX" codes appearing in the scan tool.
This is what comes up when the tool first connect.


Then run a scan of all modules and get 40 DTC's in red "P0101(1/40) Not Passed SC" and then a decription. The one's I listed are the result of a scan, then an erase
of all DTC's, then anotherr scan with different DTC's returned..
Since this is all about a misfire when the car is warm and nothing appears in the DIC, I've been using the scantool for information. The different scan results makes me
question the scantool and led me to post here. That's why the firmware and database were updated yesterday.

 

Right now you’re in Global OBD 2 it looks like !!…in Global you don’t have to put in the cars manufacturer, make, model, year, etc…what do you see when you go into “enhanced “ or “factory” OBD2 ??… in the picture upper left is the IM Status…these are the tests the car performs so you can pass inspection…if you erase the codes or disconnect the battery all the monitors will show incomplete or red in the pic…we just have to make sure you are looking at the right stuff…is this your first scan tool ??…can you take a few pictures of some of those codes in enhanced if there are any ??..you say you have all these DTC’s but pic says no codes stored ??…maybe you are just looking at a list of P codes but not what’s stored ??…if codes are erased try using the cars code reader and see what it says !!’

 

I am new to scantools (but not computers), and this is a borrowed tool. I undersand that the car has to go through a drive cycle for I/M Status to reflect reality.
But that is what I am tryoing to determine - which of the 40 DTC's may be related to an incomplete drive cycle and which maybe pointing to the misfire.
The first photo is the summary result of selecting the System Menu from the I/M Status screen (start screen), then selecting "All Module Scan". You can then
scroll through the individual DTC's. When you select the "OEM Enhanced" prompted for vehicle, enter and then presented with "Chevrolet OEM Enhanced."
When you select "Chevrolet OEM Enhanced" you don't get the scan summary, just immediately start with the detail of the first DTC.
And it shows that the first is 1 of 40.

DIC is showing just P0161 from the PCM as current.


This is the summary I get when select "Scan All Modules"

Here is the Chevrolet module. I've already selected 2000 Corvette.

Run the Chevrolet module and first screen returned is the individual DTC detail. There are 39 othes.

 

This guy has Zurich made by Innova…I thought they looked similar and these are his codes !!..look similar ??..looks like we were on a wild chase with these codes !!!…someone asked and he’s using a ZR8..somebody said that is a list of DTC’s that can be set and not what you have…somebody with an Innova sent his back because it said “not passed SC”…Innova never saw that message and he will be returning it !!…so for now we will concentrate on the P0161 and the misfires…I wouldn’t use this scan tool anymore and maybe invest in a good scan tool depending on your budget…China makes these and must have stole the software from Innova !!…let us know if you want to tackle the P0161…bank 2 sensor 2 (downstream sensor) heater circuit.,,easy to diagnose !!…won’t cause a misfire though !!
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Discussion Starter · #1 · Jan 16, 2020I have a 2001 Chevy Silverado 5.3l LS and it has a bunch of check engine code most being related to the circuit. If someone could help me figure out why I have all the codes that would be great. The truck runs fine and shows no issues whatsoever. No check engine light either.
here are the codes
P0101 MAF sensor performance
P0102 MAF sensor circuit low frequency
P0103 MAF sensor circuit high frequency
P0106 MAP sensor performance
P0108 MAP sensor circuit high voltage
P0112 IAT sensor circuit low voltage
P0113 IAT sensor circuit high voltage
P0117 ECT sensor circuit low voltage
P0118 ECT sensor circuit high voltage
P0121 throttle position sensor circuit insufficient activity
P0125 ECT insufficient for closed loop fuel control
P0128 coolant thermostat
P0131 HO2s circuit low voltage bank 1 sensor 1
P0132 HO2S circuit high voltage bank 1 sensor 1
P0133 HO2S slow response bank 1 sensor 1
P0134 HO2S circuit insufficient activity bank 1 sensor 1
P0135 HO2S heater performance bank 1 sensor 1
P0137 HO2S circuit low voltage bank 1 sensor 2
P0138 HO2S circuit high voltage bank 1 sensor 2
P0140 HO2S circuit insufficient activity bank 1 sensor 2
P0141 HO2S Heater performance bank 1 sensor 2
P0151 HO2S circuit low voltage bank 2 sensor 1
P0152 HO2S circuit high voltage bank 2 sensor 1
P0152 HO2S slow response bank 2 sensor 1
P0154 HO2S circuit insufficient activity bank 2 sensor 1
P0155 HO2S heated performance bank 2 sensor 1
P0157 HO2S circuit low voltage bank 2 sensor 2
P0158 HO2S circuit high voltage bank 2 sensor 2
P0160 HO2S circuit insufficient activity bank 2 sensor 2
P0161 HO2S Heater performance bank 2 sensor 2
P0171 fuel trim system lean bank 1
P0172 fuel trim system rich bank 1
P0174 fuel trim system lean bank 2
P0175 fuel trim system rich bank 2
P0200 injector control circuit
P0230 fuel pump relay control circuit
P0300 engine misfire detected
P0325 OCM knock sensor circuit
P0327 knock sensor circuit low voltage
P0332 knock sensor 2 circuit low voltage bank 2

 

Wtf???
Try another scantool? Check until the 0161??

 

YEP…WTF !!…we can try another scan tool to confirm the P0161 and having one would be useful to see if the O2 heater circuit is heating up while looking at live data…did one down here in Florida not to long ago on a Forum members C5 !!

 

Finally found bluetooth OBDII adapter. Connected with Torque app. Shows only the P0161.