Fault Code B1845

[recce245]

Can anyone offer any help or advice, my explorer wont start have put it on a code reader and code B1845 has come up, cant find any reference to this fault anywhere even ford are saying dont know, its to do with a Ignition Tamper Circuit Failure, can anyone offer an ideas of how to reset or bpass so we can get car to start, it turns over but wont fire, also can anyone offer a long term fix as this seems to have started as an occasional fault that cleared if car was left to sit for a while but know wont sart even after disconecting battery, my mechanic has tried all he can think of Please HELP

 

[Arrecife45]

Have a 99 XLS and had a similar problem except I could not get ANY codes. A computer car guy checked it and recommended it be taken to the shop for further analysis, the car computer had to be rebuilt and the problem was solved.

 

[recce245]

Have a 99 XLS and had a similar problem except I could not get ANY codes. A computer car guy checked it and recommended it be taken to the shop for further analysis, the car computer had to be rebuilt and the problem was solved.

Thanks for that could you explain a bit more what rebuild the computer means, did they put in a new one or just plug new bits into system thanks in advance

 

[SoNic67]

Sounds like is a PATS issue...

 

[1998Exp]

As far as I understand, there is no such thing as 'Ignition Tamper Circuit Failure' in a 2nd Gen PATS-equipped Explorer. As you've already discovered, B1845 appears to be a 'phantom code'. My 1998 service manual does not even list such thing. I recall reading somewhere that there was a TSB on the subject, albeit not for Explorers, advising to ignore it. So you may have a different problem. One possibility is a defective PATS controller (a little box behind the passenger side of the dash). Another one is that the PCM may have lost the code and does not recognize the keys.
Incidentally, most people do not know that the PCM ('computer') does not have any direct connection to the PATS system, and it only 'talks' to the PATS controller over the shared data link. Thus, it's highly unlikely that a hardware failure in the PCM is causing this problem. Assuming that the PATS controller is OK, reprogramming the PCM may be the solution. If you can put your hands on a known-good PCM from the same model and year, including the matching keys and lock cylinders (for the driver's door and ignition) this may be another option.

Can anyone offer any help or advice, my explorer wont start have put it on a code reader and code B1845 has come up, cant find any reference to this fault anywhere even ford are saying dont know, its to do with a Ignition Tamper Circuit Failure, can anyone offer an ideas of how to reset or bpass so we can get car to start, it turns over but wont fire, also can anyone offer a long term fix as this seems to have started as an occasional fault that cleared if car was left to sit for a while but know wont sart even after disconecting battery, my mechanic has tried all he can think of Please HELP

 

[recce245]

thank you

MAny thanks for your help having read everything available and getting your information as well am going to get the PCM done first, a
mta

As far as I understand, there is no such thing as 'Ignition Tamper Circuit Failure' in a 2nd Gen PATS-equipped Explorer. As you've already discovered, B1845 appears to be a 'phantom code'. My 1998 service manual does not even list such thing. I recall reading somewhere that there was a TSB on the subject, albeit not for Explorers, advising to ignore it. So you may have a different problem. One possibility is a defective PATS controller (a little box behind the passenger side of the dash). Another one is that the PCM may have lost the code and does not recognize the keys.
Incidentally, most people do not know that the PCM ('computer') does not have any direct connection to the PATS system, and it only 'talks' to the PATS controller over the shared data link. Thus, it's highly unlikely that a hardware failure in the PCM is causing this problem. Assuming that the PATS controller is OK, reprogramming the PCM may be the solution. If you can put your hands on a known-good PCM from the same model and year, including the matching keys and lock cylinders (for the driver's door and ignition) this may be another option.

 

[recce245]

update

THanks for all your help having spoken to Mechanic he not sure what unit he is looking for as there a quite a few under the bonnet in the assmbly that holds them can you offer any guidence please

As far as I understand, there is no such thing as 'Ignition Tamper Circuit Failure' in a 2nd Gen PATS-equipped Explorer. As you've already discovered, B1845 appears to be a 'phantom code'. My 1998 service manual does not even list such thing. I recall reading somewhere that there was a TSB on the subject, albeit not for Explorers, advising to ignore it. So you may have a different problem. One possibility is a defective PATS controller (a little box behind the passenger side of the dash). Another one is that the PCM may have lost the code and does not recognize the keys.
Incidentally, most people do not know that the PCM ('computer') does not have any direct connection to the PATS system, and it only 'talks' to the PATS controller over the shared data link. Thus, it's highly unlikely that a hardware failure in the PCM is causing this problem. Assuming that the PATS controller is OK, reprogramming the PCM may be the solution. If you can put your hands on a known-good PCM from the same model and year, including the matching keys and lock cylinders (for the driver's door and ignition) this may be another option.

 

[1998Exp]

Disclaimer: until seeing your 'bonnet' (engine hood on this side of the pond), I did not realize that you were in the UK. If this is indeed a European export model, the PATS system is likely to be different from domestic.
Not sure what you/your mechanic are looking for. The PCM is easily recognizable by a large rectangular connector at the top of the firewall. In this country, the location is slightly off-center towards the passenger side. After disconnecting the wire harness, it's just two screws, and the PCM box pops out.
The PATS controller is a fairly small box under the dash. In this country it's behind the glove box and clearly marked as made by Siemens. Pictures of this box have been posted on this site not a long time ago -- search and you'll find them.

THanks for all your help having spoken to Mechanic he not sure what unit he is looking for as there a quite a few under the bonnet in the assmbly that holds them can you offer any guidence please

 

[recce245]

Man thanks for your help the car is same as US version which is why Ford UK dont like helping the cars were built in Eire by ford using all parts from US just converted to RHD so you discription fits whats under the Hood will pass this info onto him. his a petrol head but somewhat in aware of the Jeep as he not used to working on 4ltr v6 cars

 

[recce245]

Thank you

Would like to offer my thanks for all the help and advice I have been given over this fault, your advice has helped our Mechanic sort the issue on our Explorer, and get back on the road, Ford UK and Europe could learn a lot from from all of you over the advice and help you have offered