Code 42. Engine turns over but won't start.

Hi. My name is Richard. I live in Utah. I'm retired on soc sec. I own a '93 Geo Metro 4dr with 153,000 miles. The charging light came on about a week ago and I continued to drive it home (about 5 or 6 miles). Upon inspection under the hood, I found the alternator/water pump belt missing. I put a new belt on and cleaned the battery terminals at the same time. They were getting corroded. The battery voltage was still good (12.8 V). The car started and ran fine. I drove it about 20 miles after that. As I was pulling into my driveway and parking, the "Check Engine" light came on. Now when I try to restart it, it will turn over, but not start. I checked the code stored in the ECM and it flashed 42. I can't see any problems, but I am completely lost as what to look for. Please help. Thanks.

CODE 42

Trouble Code 42 indicates that there may be a malfunction in the Electronic Spark Timing (EST) system. During cranking, the timing is controlled by the ignition module and the ECM grounds the EST line. It expects to see no activity on this line at this time. When the ECM enters EST mode, it applies +5 volts to the BYPASS line and expects to see voltage variations on the EST line.

Reasons for the ECM to set Code 42:

- System in BYPASS mode (i.e. EST line supposedly grounded) but activity sensed on EST line

- System in EST mode (i.e. BYPASS line driven with +5 volts) but no activity seen on the EST line

Possible causes include:

1) BYPASS line is open or grounded

2) EST line is open or grounded

3) Poor connections between ignition module and ECM

4) Poor routing of EST harness and/or poor quality ignition wires (EMI induced electrical noise

5) Faulty or incorrect ignition module

6) Faulty ECM

Actually I have a geo 93 metro too. I have a 3 cylinder and there is no ignition module. A code 42 on a 3 banger means no signal from the camshaft sensor for more then 2 seconds.

The precedure to test the cam senor is to unplug the sensor and then hook your meter up to the sensor and monitor A/C voltage from the sensor while cranking (should be between .2 and .4 volts). The sensor is nothing more then 2 small magnets but it costs $150 new :O. So DieInterm has the right idea on looking at a bone yard for a replacement.

Thanks for the replies. They give me some things to look at. I have a little bit of time this afternoon, so I'll let you know what I find.

I was able to look at it this afternoon and I pulled the distributer cap off. I had an assistant (my wife:grinno: ) crank it over and discovered that the rotor wasn't turning. I then watched the crankshaft pulley while it was cranked and it turned OK. I pulled the top three bolts of the timing belt cover and by lightly flexing the cover back I found that my timing belt has broken. I wonder why the code 42? Is there anybody in the SLC UT area that would be willing to change it for me (for a fee, of course)? I don't feel up to the task and I'm sure the stealer (Ooops! I mean dealer) would charge me a lot more than I can afford to pay.
:banghead:

About the ignition module located in the distributor, why does it read, "do not remove"? Does it have so be alligned carefully? What would happen if were removed and then reinstalled by a non-proffesional? :wink:

Jai

:rofl:
Followup on original post of this thread:
I checked with dealer on price to do this job (Replace broken timing belt in '93 1.0L Metro). $345!!!! I called a local mechanic shop that I have used in the past: $250!!!! I couldn't really afford either option, so I went to Checker Auto Parts and bought a Goodyear timing belt for $21.00. Then I dedicated Sunday to doing the job myself. Cleaned out my garage, lit my propane heater (temperature here was 26 degrees when I started the job), pushed the little bugger into the garage and went for it. It took me 3 hours to complete, but I saved at least $225 by doing it myself. I figure $75/hr ain't bad wages! I started the engine before putting the timing belt cover & other belts back on. It started immediately and sounded GREAT! The hardest job for me was getting the tensioner pulley back on with the "ear" of the bracket in the tensioner hole. Had it off & on 4 times before I got it right. After putting everything back on it started right up. I took it for a 4 or 5 mile test drive & I'm SURE it runs better now than before. Sorry for the long post, but I'm proud of the job that I did. I'm 66 yrs old and have arthritis in my knees and back so bad that sometimes I have a hard time walking. This forum is invaluable for people who want to keep their cars on the road.

Congrates on your repair VCR :)



About the ignition module located in the distributor, why does it read, "do not remove"? Does it have so be alligned carefully? What would happen if were removed and then reinstalled by a non-proffesional? :wink:

Jai


The "do not remove" refers to the black cap on the sensor. You can pop it off but you really don't want to unless you pull the sensor off first. Secondly - yes, this sensor is one that must be aligned, I believe the spec is that the tab on the sensor must be .2mm (.04in?) from the pegs on the distributor.

Yeah, those tensioners are a pain in the ass. It took me a long time, trying several ways to get it to go. In the end, I used a large slotted scredriver to lever the belt onto the tensioner. Not the best way, but you start to lose patience doing that kind of stuff.

Good for you for doing it yourself!

Jai

I replaced my timing belt myself this last summer.

No problem whatsoever. Was EASY. I'm 62.

How tight should the tensioner pully be?

Do the tensioner pully bearings ever go bad?

DoctorBill

PS - I allowed the cam shaft pully to rotate while the belt was off
and got REALLY scared that I 'screwed the pooch.'

I lined up the two marks on the cam shaft pully and the main engine
belt pully and the engine worked. Scared the crap out of me though!

I hope I did it right. The engine worked. I never went back in there
to see if the belt stayed tight nor slipped. I should though, huh?

If it slipped you'd know because the cam timing would be screwed and the car would run like sh**, if at all. The tensioner is supposed to be pushed, by hand, into the belt and then you let it relax into position and tighten it down at that position. The spring determines how hard it holds the belt (not much).