I pulled the ignition module and cleaned the brass cams in August, clearing up my check engine light. Last week, I hit a bump in the freeway and the light came on. Now she is backfiring and running like crap. I'm showing codes P0440 History and Current, and a number of loss comm codes (u1096, 1064, 1016). This points to the ignition module that I rebuilt in Aug.

My question is, do I repair it again or should I replace the whole module? If the answer is the latter, what sort of $$ am I looking at (I'll do labor).

TY

 

I'll definitely take a look at that this weekend. It would be awesome if I didn't have to pull the whole dash again.

 

I took a look at the door wires and they all looked good. The contacts were all clean and everything felt seated. Now I'm looking at replacing the ignition module completely. Does anyone have any links to a new one? Advice is always welcomed as well. TX

 

What does the P0440 code refer to? I looked in my 98 factory service manual and it's not listed, then I looked at 97vette dot com under the 97-00 codes and it's not listed there either.

 

to tell you the truth, I do not know for sure. If I remember correctly from last time I had this problem, it has to do with the fuel system. The numerous loss comms are whats pointing me to the ignition module as the codes are identical as the last time. I did the freebee fix on the copper cams, but I would not be surprised if they failed again. Time to just replace the module.

 

DTC P0440
Description
The EVAP large leak test applies vacuum to the evaporative emission (EVAP) system and monitors vacuum decay. The control module monitors the fuel tank pressure (FTP) sensor signal to determine the vacuum decay rate. At an appropriate time, the control module turns the EVAP canister purge valve ON (open) and the EVAP vent valve ON (closed). This allows the engine to draw a vacuum on the EVAP system. At a calibrated time, or vacuum level, the control module turns the purge valve OFF (closed), sealing the system, and monitors the FTP sensor input in order to determine EVAP system vacuum. If the system is unable to achieve the calibrated vacuum level, or the vacuum level decreases too rapidly, DTC P0440 will set.

Conditions for Running the DTC
DTC P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0125, P0443, P0449, P0452, P0453, P1106, P1107, P1112, P1114, P1115, P1120, P1220, or P1221 are not set.
The ignition voltage is between 10-18 volts.
The barometric pressure is more than 75 kPa.
The fuel level is between 15-85 percent.
The engine coolant temperature (ECT) is between 4-30°C (39-86°F).
The intake air temperature (IAT) is between 4-30°C (39-86°F).
The start up ECT and IAT are within 9°C (16°F) of each other.
The vehicle speed sensor (VSS) is less than 121 km/h (75 mph).
Conditions For Setting the DTC
The EVAP system is not able to achieve or maintain vacuum during the diagnostic test.

Action Taken When the DTC Sets
The control module will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test ran and failed.
The control module will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.
Conditions for Clearing the MIL/DTC
The control module will turn the malfunction indicator lamp (MIL) OFF during the first trip in which the diagnostic has been run and passed.
A last test failed (current DTC) clears when the control module turns OFF the MIL.
The history DTC will clear after the control module runs and passes 40 consecutive warm up cycles with no failure.
The DTC can be cleared by using a scan tool.
Diagnostic Aids
Use the EVAP pressure/purge diagnostic station in order to pressurize the EVAP system to aid in locating intermittent leaks. Move all EVAP components while testing with the J 41416 Ultrasonic Leak Detector.
A temporary blockage in the EVAP canister purge valve, purge pipe or EVAP canister could cause an intermittent condition. To repair a blockage in the EVAP system refer to Evaporative Emission (EVAP) System Cleaning
Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.

 

Hmm, backfiring and running like crap? Fits perfectly with a large vacuum leak. I would start with the easy stuff like behind the intake manifold for a good connection of the vacuum line at the MAP sensor area, then check below the battery behind the PCM for damage to the vacuum lines in that area. I believe these are the most common sources of vacuum leaks. I would guess you hit the bump and a vacuum line came loose, good luck pinning it down.

 

I'll check again for vacuum leaks. I did Not check under the battery so it is possible that might be my problem. For the record, I still believe it to be the Ignition Module as I had relatively the same symptoms last time.

 

When you say "Ignition Module" are you referring to the ignition switch?

 

From another thread:

Quote:
Originally Posted by 87SAM
Not really.

Condition/Concern:
DTCs U1016, U1064 and U1096 may be present when scrolling through the onboard diagnostics via the instrument cluster Driver Information Center (DIC).

Recommendation/Instructions:
This is a normal software function as long as the DTCs have a history status upon ignition cycling. No repair attempts should be made.

As a further explanation the modules on the serial data bus communicate with each other. They send out State of Health (SOH) messages to each other on a frequent basis. Sometimes the receiving module doesn't actually receive the message or its response to the message doesn't get back to the requesting module. When that happens you get the Ucodes. Sometimes it is nothing more than electrical noise on the bus that stops the message other times it could be the bus is too busy. If the message gets through the next time the system goes happily on its way. If the message continually fails to ge through you may see the No Comm message.

Bill

 

Yes.

 

Ok, so I went through the vette this weekend and there are no vacuum leaks present. I am going to replace the ignition switch, however I would like any advice on where to get one (besides dealer)

 

Ecklers. I had one on backorder last year but then decided to try Bill Curlee's cleaning technique. I cleaned the contacts per his instructions and cancelled my order.

 

Call Fichtner Chev @ 1-800-234-5284 They are a long time forum vendor. Ask for Bob in parts dept and be sure to tell him you are a Corvetteforum member.

HTH

 

Sweet, TY guys.

 

I replaced the ignition switch module and it did NOT fix the problem.
The car wants to run right, but something is causing too much fuel to be injected, therefore making it run extremely rich. I'm thinking stuck open fuel injector. Any other ideas?

 

Is this something I can diagnose myself? I don't want to, but I'll take it to the shop if I have to.