Paddy1

Recently purchased a 2012 chevy express van 4.8 2500 71k. Not passing emissions. The CEL does not illuminate on starting whereas all the other warning lights do. So maybe the bulb is burned out, loose wiring, fuse etc. The dmv smog test shows the following codes:1) P0650-malfunfunction indicator lamp short circuit 2) HO2s 12 heater resistance P0054 3) P0496 evaporative emission system high purge flow.

In the test results it shows FAIL under the READINESS section, everything else passed. It also shows the following tests as not complete: 1) EVAP CONTROL 2) O2 SENSOR. I have read some stuff about “drive cycles” and “readiness monitors” and it gets a little complicated for the average car owner, like say someone with little technical knowledge. I was not aware that these things could affect your smog test.

I have experience with obd11 scanners and auto repair. But the last vehicle I worked with was about 15 years older than my van. I plan on keeping the van so to start out I will need a decent obd11 scanner and a set of GM shop manuals.

I like the ELM base platform which works with USB and windows 10 laptop, something that will read PID’S, reset readiness monitors, drive cycles, DTC’S etc. Not Bluetooth or apps, just straight forward windows 10 with laptop. Any suggestions are appreciated.

My questions are: 1) any ideas on the CEL 2) any ideas on the DTC’S showing up 3) How can I pass emissions?

Thank-you

tech2

1 for the cel; buy a subscription to a service information site. identifix is one such service. this will provide diagnostic information and instruction for the fault code p0650. Most likely a bad cluster or a previous owner tampered with the cluster. I have seen vehicles where people desoldered the led for the ses light.

2 check the 02 heater fuses. if they are good...inspect the 02 sensor wiring...they are known to chaff on the frame rails. if ok...replace the sensor

3
do you have any issues starting after refueling?

Paddy1

I checked the fuses both sides, some had to be checked with key on. I was hoping to find the lighter/dlc fuse blown but it was good. I am concerned about a 40 amp fuse nr 45 labeled Engine control module/powertrain because the fuse is actually missing. Any reason for someone to pull this fuse? Could it be the reason my CEL does not illuminate? The van runs well, just need to figure out this fault code p0650.

On a few occasions, I noticed issues starting after refueling, but still started.

I ordered a cd for $14.99 2003-2016 chevy express van dealer service manual, do not waste your money, the cd was almost useless. Very difficult to find area to reference for your vehicle.

Service information site. Identifix was a little pricey. I think I may bight the bullet and purchase the actual shop manual set, ebay has it for $219.I plan on keeping the van long term so why not dish out the dough for the manuals.

Triaged

You mention a smog check so that means you might live in California. California requires the seller of the vehicle to have performed the smog check. There is also a provision for charging the seller for the repairs of any tampered with smog equipment. Normally I am more on the buyer beware side of things. I hooked up a scan tool before buying my van and looked how long ago since the codes have been reset. In my case it matched the time since the previous owner had taken it to the dealer for a recall and he had all the paperwork to back it up. In your case it sounds like the person that sold you that vehicle did some shady stuff and you should use the full extent of the law to make you whole.

Paddy1

Why would someone pull the 40 amp fuse nr 45 labeled Engine control module/powertrain, because the fuse is actually missing. Would this missing fuse disable the CEL light from illuminating? If the fuse is missing and it controls the malfunction indicator lamp circuit, the circuit would not complete itself, therefore no CEL light. Can anyone tell me if the missing ecm/powertrain fuse would cause this?

William Kisselstein

Seems to me the codes tell you what's wrong, there's a short circuit in the wiring to the bulb, which to me would call for removal of the cluster and inspection of it and the wiring.