I have been getting a Fail Safe Engine Mode message intermittently. That has been alternating with a check engine light. Code reader gives three codes; P0443 - Evaporative Emission Control System Purge Valve Control Circuit; P1642 - CAN Link Circuit and P1000. Fail Safe message goes out after car is shut off and may or may not come on when engine is started, but usually not until engine warms up. The Fail Safe mode does not seem to affect performance. I cleaned engine ground strap connections on both ends and cleaned and reapplied silicone di-electric grease at the connectors for the throttle body. Suggestions on where to look next?

 

I tried a hard reset, but that had little effect.

 

a p1000 means either a reset/battery disconnect/ and/or the pcm did not go through its full evaluation- probably because of the 443 code- p1000 means nothing ( except when someone tows a car in in desperation- please do NOT CLEAR CODES before going to the dealer ) OK- I am better now. I would estimate 80% of the time a 443 is a faulty canister purge valve...18 % wiring damage- 2% pcm, change the valve and be happy

 

What causes the P1642? I have no idea what a CAN circuit is.

 

Mike:
CAN is Controller Area Network and is a Bosch developed network for robust, point to point networking. It is how the various modules talk to each other. The fault you have can also be triggered by connecting (and, I assume, disconnecting) the OBD reader. I THINK the way to tell if it vestigial to connecting the reader is to notice if the CEL comes on after the reader connects, assuming no other code.

I think the dash panel is the bus controller from the faults described, but I am certainly not sure. In any case, troubleshooting the bus is done be using the dealer level software and interrogating each bus node to see how many CAN faults are stored.

I find it interesting that you say RP does not seem to affect performance. I thought it would limit the rpms to 3000 when active.

Any number of things can trigger RP, check the archives for many long and painful stories running it down, and some do not trigger a "generic" OBD fault. Some do. I would be suprised if your purge code was the source of RP, because RP is a strategy for the car to protect itself, and purge would not seem to be in that catagory.

On the other hand, your CAN fault might well be real, and the RP is done because the tranny controller and the engine have lost sync.

Only other thought- Are you running a full time OBD scan like a "Real Gauge?".

 

I am using an Actron OBDII Reader to check codes.


I can rev past 5500 rpm on hard acceleration with the fault showing on the Odometer, I also thought RPM would be limited. It is the times past that Restricted performance was indicated.


There isn't a shop in the greater Lafayette Area that could run the more sophisticated tests you describe. I hate to have to take it to Baton Rouge to the Jag Dealer.

 

What is CEL?

 

I am not getting Restricted Performance alternating with the Fail Safe Engine Mode.

 

Hmmh.
Sorry, I did not notice your specific symptom report, and I assumed the RP came with the Fail Safe. No doubt, that might be significant, but I don't know what it means.
CEL is check engine light.
Good luck.

 

I swapped out my brake light switch and this fixed my fail safe error.

 

Ross asked if you were running with a reader plugged in. That in itself could cause the P1797 due to poor sync.

 

I did run the engine with the code reader plugged in after a half dozen times of the problem showing up. But car was in park when I read codes with the engine running. I initially got codes off the reader with the key on but engine off when I started this thread. Same codes throughout every time I would check. Reader will not function without the key turned on, at least with the Actron unit I am using.


I am intrigued by changing the brake light switch making the problem go away for one of the posters. Were there any other problems with the brakes that would explain what prompted the replacement of the switch? Why would the brake light switch cause Fail Safe Engine Mode? I don't understand the science.


I also picked up on the connection between the trans and the ECM being a possible cause. I cleaned the connector contacts at the connector at the top of the bell housing mounted on the same bracket as the O2 sensor connectors. The weather took a turn for the worst, so I will have to wait several days before cleaning the round connector on the transmission.

 

Change the purge valve. Search for threads on that issue.

If your cruise control is working, prob not brake switch.

I run with the actron connected all the time, no problems, lets me read fuel trims real time and accurate coolant temp.

 

I had check engine light first after filling with gas, then fail Safe Engine Mode, but lately check engine light has been off, but fail safe engine mode comes on.


These inconsistencies are what got me wondering if any codes were different if checked with the engine running, but I only get the P1642 and P0443. I will check the codes again to see if I still get the P0443 or just the P1642. I will report back tomorrow

 

Mike,

These cars are glitchy. I don't know why I'd get chk engine some times, cruise working on and off, fail safe engine mode, and occasional other problems. The one most aggravating was turning the key on and getting nothing. I'd have to turn it off and try again at least 3 times and it would crank.

The brake light switch seems to have been the culprit. I've been error free for the last 2 days. Car cranks 1st time every time. It must tie several circuits together including the cruise.

I got it from Ebay for $45.

 

I got curious this morning on the way to work and checked codes after I stopped on the way after the Fail safe light came on. Only codes were the P0443 and P1000. As usual Fail Safe light was out when I restarted. I had not used the cruise control in a few months due to a short commute. It would not set.


When I arrived at work, I shut engine off and kept key on and noticed that with car in park and key on, brake lights were still on. After turning the key off, brake lights went out. Started the car in park and the brake lights were still out.


So, in addition to the purge valve code, there does seem to be a brake light switch issue. I ordered a switch and have a spare purge valve. Once the weather gets cooperative (no rain) I will swap both out, starting with the brake light switch. I will drive the car and see if the Fail Safe Engine Mode comes back. After a day or so, I'll swap out the purge valve.


I will report what I find. I did not even realize I was having a brake light problem.

 

Well, I installed a new brake light switch and it cured the problem.


Switch consists of two micro switches actuated by a rotating cam. Cam moves by a pin welded to the brake pedal.


Check engine light was solved by replacing the check valve under the hood(bonnet)

 

Thanks for getting back, but what is the check valve under the hood that you replaced?

 

Evaporative valve (?) might have nomenclature wrong. Perhaps Purge Valve?


Notice that the newly installed valve has a pressure valve where as the original removed did not.

 

This is the 3rd time in a short period that I read the brake light switch solves these problems.
Surely something to consider for others getting these faults.
Glad u solved it.