360 Limp mode after refuelling

You need a code reader, not a generic OBD2, but something like the Thinkdiag or AP200. Reading the code can really help get an idea of what could be going on.

 

What do you mean by limp mode? What are your dash indications? CHECK ENGINE light? SLOW DOWN?

 

Sounds like throttle body trouble to me. Check your OBDII codes for clues. Unfortunately, new throttle bodies are unavailable so you'll have to be creative if this is the problem. A generic code reader should be good enough if that's all you have.

@Qavion - Limp mode in the 360 is when the throttle only response to 20% input. The engine will still rev up a bit but essentially, you're idling along. It's very frustrating when it happens and resetting the ECU with the cutoff switch only solves the problem for a mile or two before vomiting out a couple codes and calling it quits.

I believe limp mode (the kind without a check engine light) is caused when a mismatch between the throttle bodies that can't be corrected by the ECU occurs. The bad thing about throttle body failure is it can take out the primary ECU by drawing too much current through the H bridge powering the throttle bodies. That causes the solder to melt and bad, bad, really bad, things to happen.

 

Drive it more?

 

I always thought that the solenoid in the vapor canister was bad if a car only stumbled after a fill up.

 

Maybe it is an environmental issue due to the seasonality of the fuel in your location?

In the US, we have "winter" and "summer" gasoline blends. The main difference is the Reid Vapor Pressure (RVP) spec. RVP is higher in winter to ensure prompt starting; and conversely lower in summer to avoid vapor lock. Perhaps you have lots of "winter" gasoline remaining in your tank and the ECU is at its adjustment limits trying to make the desired adjustments?

 

For me this sounds like you have a fuel shut off valve failure saturating the charcoal canister with raw fuel then when the engine management system request purging the engine is over whelmed with unwelcomed fuel or oversaturated vapors causing a over rich condition.
1-Like mentioned above get a code reader that will give you a clear perspective what the engine management system is complaining about.
2-If codes point to fuel adaptation challenge remove charcoal canister and inspect for over saturated signs, typically when this happens the canister is unusually heavy.
3-Some of the better scanners can perform a fuel tank test which test the integrity of the entire system. Large leak to small leak.
4-Just for the record when you disconnect the battery what you are doing is resetting fuel adaptation to base value which may explain why it runs so good afterwards until the system can not adapt any more for the over rich condition.

I drive my 430 very little also with no fuel stabilizer.

Good Luck.

 

If you have a code, here is the official Ferrari 360 decoding chart:

 

All active codes will be shown.


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If the throttle bodies are the problem, you may not see any codes at all, especially if you've recently reset the ECU with the cutoff switch. I chased TB problems for nearly a year before nailing that down as the problem.

There are three ways I know of to "fix" throttle body limp mode problems:
1. Replace your existing throttle bodies with used ones from a breaker. Unfortunately, this is a hit and miss unless you can buy two from the same working car.
2. Rebuild the throttle bodies with parts from a donor throttle body. This is an excellent solution if you're DIY and very careful.
3. Purchase a kit that allows your car to use cheap Porsche throttle bodies.

I wrote several articles on the throttle body issue.

https://www.ferrari360.org/2020/07/bosch-throttle-body-replacement.html

Testing a TB: https://www.ferrari360.org/2022/12/make-bosch-throttle-body-tester.html

Throttle body adapter: https://www.ferrari360.org/2022/03/ferrari-360-throttle-body-adapters.html

 

When in a limp mode scenario (after your re-fueling event), I would first check to see what my fuel pumps are doing.
Have you checked the fuel pressures on either side? Maybe you're running on one pump only.

I also agree with FB242, "... For me this sounds like you have a fuel shut off valve failure saturating the charcoal canister with raw fuel then when the engine management system request purging the engine is over whelmed with unwelcomed fuel or oversaturated vapors causing a over rich condition..."

 

Right. The solenoid in the vapor canister is bad.

 

We may need more info on your "limp mode".

Are the engine rpms limited to, say, 1500rpm, or is the engine just running poorly? If the rpms are limited to a specific value, then the throttle bodies could be the issue. If the engine is just running poorly, then it could be a vapour canister issue.

 

In "limp" mode, the rpm's don't appear to be limited. It's the throttle that's limited to 20%. If you wait long enough, you can get going up to speed, but a Yugo running on two cylinders is going to pass you and flip the bird.

If the throttle position is checked with an OBD tool, you can see it's limited to 20% no matter where the pedal position actually is.

 

What happens if you drive same distance to gas station (no gas), turn the car off for 5 min and restart it?

 

Is this from personal observation, John? I was looking through the manual and couldn't find any reference to "limp" mode. There was a "recovery position" which I assumed to be the same. That mentioned 1500rpm, but now I see that only 8%.

 

Yes, personal experience. I did read about it somewhere, maybe the newer version of the WSM? It might have been a Bosch publication.

When viewing the live data for the throttle pots, the value stops at 20% no matter where the pedal is beyond that. 20% is damn little throttle too. Just a touch and 20% is hit. This limp mode produces no CEL. Sometimes it won't even throw a code right away. Eventually, it does, usually two codes:
P1189 - Pedal Position Potentiometer Signal
P1149 - Pedal Position Potentiometer Signal 1
Sometimes others...

Naturally, these codes are misleading and typically cause the owner to buy a $400 part that does nothing to change the situation. It's a lot cheaper than two TB's, is easy to replace, so that's what is usually done first. The problem may even appear to be resolved, only to rear its ugly head at just about the time the owner is starting to feel cocky about fixing it.

 

Thanks for the hint. I found a Bosch publication and "Limp Home" mode is mentioned 191 times. The publication itself is gibberish to the average human, however, especially on a Sunday morning. This is Trevor-level stuff.

There seems to be a limitation on torque during limp home mode, so you are probably right about there being no fixed rpm limit. Unfortunately, there seems to be a number of triggers for limp mode, not just the throttle bodies. "Speed sensor" is mentioned as one cause.

We need some codes.

 

Ian, im not hinting for you to do it but Would it be to difficult to make a list of items that would make a car go into limp mode out of that article?

 

A loose fuel cap can cause this. Check the seal on the cap.

It's a quick check to rule one possible cause off of the list.

 

It's a 1,327 page document full of acronyms and flow charts, but I think I've narrowed it down to the following three (or four? or five?)...

Engine speed sensor
Phase synchronization (cam sensor?)
Throttle valve position (E DK) and "main load sensor" (E_DM)

Here is some of the text:

NLPH 5.20 limp-home for phase synchronization
FDEF NLPH 5.20 Function definition
The section NLPH describes the checking of the synchronization by means of the correctly operating phase sensors given in the
system. The cylinder counter zzyl is initialized from the phase information during the synchronization in %GGDPG. With defective
phase sensor (PG) and not defective phase sensor 2 (PG2) (SY PGRAD2 > 0 and B phsok2) the latter is used for the synchronization
(SYNPH2). If the PG2 signal also lies above the reference mark (SY PH2OFST = 0), then it is possible to synchronize directly to
PG2 with defective PG. Otherwise always PG is synchronized to and in the cycle R synph2 PG2 is used to check for correct
synchronization and to trigger a new synchronization (SYNPH1) if necessary. If no PG2 is given or if it is also defective the
cylinder counter is initialized from the virtual engine position, provided the run-on position is valid (B ale = 1).
At not clear phase position it is optionally possible to cause a double ignition output and by means of injection cut-out misfiring
can be stimulated, by the evaluation of which the correct phase position can be determined and possibly a new synchronization is
started (SYNMD).

APP NLPH 5.20 Application hint
With double ignition output it may be necessary to decrease the maximum engine speed (NMAXDZ) in order to protect components.
Allocation of CWNLPH (condition: respective bit = 1):
0. Bit: not occupied
1. Bit: run-on detection permissible
2. Bit: limp-home via double ignition (NLPH 5.10)
3. Bit: new synchronization after detection by means of cylinder cut-out permissible
The remaining bits are still free.
The cylinder cut-out can be disabled by a limitation of the operating map.
Typical Values:
---------------
ANZEAUS: 5 Number of injections to be cut-out
NPHERKMN: 2000 rpm Minimum engine speed for phase search
NPHERKMX: 4000 rpm Maximum engine speed for phase search
NPHINVMN: 2520 rpm Minimum engine speed for new synchronization
NPHINVMX: 3520 rpm Maximum engine speed for new synchronization
RLPHERKMN: 40 % Minimum load for phase search
RLPHERKMX: 60 % Maximum load for phase search
TPHERKMN: 80 C Minimum engine temperature for phase search
TPHSABSP: 10 s Blocking time for the phase search, if the appropriate operating range was exited
(should not be chosen too high!)
TPHSSP: 60 s Blocking time for phase search after unsuccessful search
ZYLEAUS: 0 Cylinder to be cut-out
The number of injections to be cut-out is to be limited between 4 to 7.
For ZYLEAUS a 0 is to be entered for the 1st cylinder and so on until n-1 for the nth cylinder.
Adjustable variables in other functions for NLPH:
%NMAXMD NMAXDZ Half the maximum engine speed, e.g. 3400 rpm for systems with single-spark coils
Maximum engine speed, e.g. 6800 rpm for systems with twin-spark coils
DNMADZ 10 corresponds to a ramp of 1000 rpm
%GGDPG DZZSTNLP 116 corresponds to 2 engine revolutions

There are ambiguous lines like:

Pedal-travel sensor limp-home operation
Throttle-valve actuator limp-home operation

Is pedal travel sensor data failure a cause for limp-home, or is this a limp-home mode using available pedal travel data?

"CWKRNLR FW = code word for limp home in case of 1 out of 2 knock sensors fails"

Is this another cause or does it concern a subsequent failure during limp-home mode?

 

That makes perfect sense.... but not a single mention of it in the Bosch document

 

I once got a SLOW DOWN light (Cat temp related) and a code which threw the car into the granny mode.
On the next exit ramp which went uphill I could barely make it up. Shut the car down, waited 5 minutes and it drove as if nothing happened for the entire trip