Next Up! Invisible CEL

Mr. Detail · Post by **Mr. Detail** » 26 Jul 2018, 11:16

Not sure what to do here. Just went out at lunch to my local auto parts store and asked them to pull what I assumed would be a code or two. My "Check Engine" light is illuminated and has been for almost a week.
The guy hooked up his code reader but then proceeded to tell me there are NO codes. What's up with that?

Post by **jimmy57** » 26 Jul 2018, 11:52

Transmission can ask for CEL and some readers don't get the TCM request for CEL to ECM DTC.

Mr. Detail · Post by **Mr. Detail** » 26 Jul 2018, 12:06

jimmy57, I don't like that response "transmission". So I guess I will need to go back to my mechanic with his $10k reader.

equiprx · Post by **equiprx** » 26 Jul 2018, 13:32

Some of our codes can appear then if the ECU does not detect it after a few miles it erases it.
I'm told that it's the way it's supposed to work.

Post by **abscate** » 26 Jul 2018, 14:44

Clear it and drive it. Its a robust system but not perfect. You can actually have pending codes which are stored but do not trigger the CEL, too.

Mr. Detail · Post by **Mr. Detail** » 26 Jul 2018, 15:23

Damn, I have had these wheels only 2 weeks and all it seems like I am doing is clearing codes. Looks like I will need to invest in a good code reader for the garage.

Post by **mrbrian200** » 26 Jul 2018, 17:52

Been there, done that...first Volvo.. shopping without a VIDA or some other professional level scanner is a game of roulette. The (majority) of good ones with zero issues get snapped up by friends or relatives. We all think we're going to find the exception... 'a perfectly good one with zero issues that nobody wanted'. There is no such thing.

Hopefully you'll get lucky like I did with an issue that doesn't require major work. Chances are somebody else looked at it previously and gave up for whatever reason, either too costly or couldn't figure out what the problem was. I recommend setting yourself up with the VIDA-DICE clone. 'better scanners' in the $150-300 range still aren't professional/dealer level. Which you'll probably need, and VIDA-DICE is. Or take it to a dealer or independent Volvo specialist and see what they say.

Georgeandkira · Post by **Georgeandkira** » 27 Jul 2018, 05:18

If you're ever near Hackensack, New Jersey (your neighbor) give me a shout and we can plug in my BSR-PPC reader.
Nothing like VIDA but it does pull "real" Volvo nomenclature codes. I have no idea if it reads pending codes.

Mr. Detail · Post by **Mr. Detail** » 27 Jul 2018, 05:45

OK, thanks guys for the suggestions. I went to Pep Boys (Ugghh) last night for another chance to pull any codes. They pulled two (2) codes for me. Actually the same two codes as 10 days ago. Here they are but not sure what to fix next.

A code P0442 most likely means one or more of the following has happened: A loose or improperly affixed gas cap. A non-conforming gas cap (i.e. not factory/original brand) A small leak/hole in a fuel vapor hose/tube. Other small leak in EVAP system. (I just replaced the gas cap with a new Volvo one.)

What causes the P0012 code?
* The variable camshaft timing (VCT) oil control valve (OCV) stuck in the open position.
* The camshaft phaser is damaged and stuck in the retarded position.
* Oil flow problems to the VCT piston and phaser.

Post by **RickHaleParker** » 31 Jul 2018, 15:33

P0012 = ECM-640F Camshaft reset valve. Faulty signal

Diagnostic trouble code (DTC) information

Condition
If the engine is hot when the ignition is switched on, an adaptation of the reset valve (Continuous variable valve timing) takes place. The control engine control module (ECM) then checks that the continuous variable valve timing (CVVT) limit position is reached. If this limit position is not reached, the engine control module (ECM) registers this as a fault and stores diagnostic trouble code (DTC) ECM-640F.

Substitute value
none.

Possible source

Incorrect signal:
incorrect base setting of the timing belt.

Fault symptoms
Malfunction indicator light (MIL), on
uneven idle
poor performance.