Code 42 after resetting computer

[TurboTdr3.8]

Yesterday I was going to do some logging and I reset ecm and started car and noticed Check Engine Lite was on , I had the power logger going , went to trouble codes and it said code 42 C3I EST or ByPass Circuit Failure, all I did was cut the car off a couple times and restart and light went back off , has anyone had that to happen , do I have a wiring problem or where do I start to check whats going on , Im having running problems anyway so I thinking this could be my culprit .BTW this is a brand new coil and module with just a very few miles on it .

 

[Front Mount]

Yea, I had a code 42 and 43? Cam sensor failure two weeks ago. Car just died while driving. Would finally restart after lots of cranking with foot to floor clear flood mode. Run a little and die. Went home on a flat bed. Not sure I even had a check engine light. Troubleshooting cam sensor cap looked good. Resistance check between coils was good, 12K or so. checking across each coil or three measurements. Reset computer and still had code 42 and 43 joined after trying to start. Mine was a computer. transferred chip over and everything good to go. Not sure that is your problem. From your mods, you probably know more about these cars then me so hope I'm not insulting.

Other simple things to do, is check computer for signs of water intrusion, and reset chip (with orange wire disconnected). Check plug wires. Running bad maybe try disconnecting MAF and see if it runs limp home mode any better? Power logger, check computer connections, and unfortunately with new coil pack and module it might be suspect. Can you borrow one or have an old one?

From old GNTTYPE.org here is what to check HTH

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 while the ECM monitors the engine speed. When the engine speed exceeds 400 RPM, the ECM sends a BYPASS signal to the ignition module which switches the timing to ECM control. The ECM calculates what the timing should be then "tells" the ignition module via the EST circuit.
An open or ground in the EST circuit will stall the engine and set a Code 42. The engine can be re-started but it will run on ignition module timing.
The conditions for setting this code are:

• System in BYPASS mode but the ignition module is still controlling timing
  - or -
• Engine speed > 600 RPM with no EST pulses (ECM controlled timing) going to the ignition module for 200 msec.

Typical causes for this code include:
1) BYPASS line is open or grounded
2) EST line is open or grounded
3) PROM or CALPACK not seated properly in the ECM
4) Poor connections between ignition module and ECM
5) Poor routing of EST harness and/or poor quality ignition wires (EMI induced electrical noise)
6) Faulty or incorrect ignition module
7) Faulty ECM

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[Front Mount]

Oops, I had code 42 and code 41 came when I tried to start.

 

[TurboTdr3.8]

Run it some more today and checking all the wires at module and ecm , pulling on them and checking for pins not in all the way but have not found nothing , Ran today with no problems or ses light never came back on , must have been a glitch somewhere . Thanks for all the good info Front Mount

 

[TurboBob]

intermittent connection on the PowerLogger can cause this, code 42 is a wierd one. Its usual causes are the connections to the coilpack, or a bad coilpack, but the internal error counters can get confused by bad connections to the PL (direct scan suffered similarly).


Keep an eye on it and let us know if you see it again.

Bob

 

[TurboTdr3.8]

Thanks Bob for the info on the PL .