97 4Runner Electrical problem
in [Toyota Trucks]
|
Prev: 99 Sienna 12V power aux outlets dead
Next: Toyota asks supplier to cut price 30-40%, switch to cheaper materials and parts
From: Jeff on 26 Dec 2009 21:15 Your reasoning appears sound. Of course, this is the type of problem that may not reappear, leaving you clueless as to whether all the fooling around did any good or not. And, you're probably inadvertently erasing any codes. But, what else can you do? How much more trouble would it have been to include OBDII scan and clear functions in the operating controls of the vehicle (not requiring the acquisition and use of a scan tool)? I say optional ABS, since my '98 Tacoma does NOT have ABS, nor the automatic locking front differential. 4Runners may have had ABS standard. Does the ABS controller store codes? JMc wrote: > I do ABS brakes, though they are factory. But you raise a good point. > I am now thinking the Brake light on the dash is a result rather than a > source indicator. My sense is the electrical interruption is long > enough for the ABS circuitry to sense and it is lighting the dash light > to indicate they are not ready for emergency stopping. > > I am back to tracing the electrical feeds from battery, alternator, > starter and ground. It's pouring rain, melting our snow pack, and even > a dry garage is not a comfortable place for crawling around, but better > than a ditch somewhere. > > Thanks, > Jere > > "Jeff" <Not(a)dot.net> wrote in message > news:4b35a9ea$0$30841$822641b3(a)news.adtechcomputers.com... >> Do you have the optional 4 wheel brake equalizer gadgetry, AntiLock, >> or whatever they call it? "Brake Light" makes ME think BRAKES! I >> never liked the looks of all that plumbing... >> >> Or... the optional automatic locking, i.e., vacuum operated, front >> differential comes to mind. Another plumber's bad dream. >> >> Check your wiring, including grounds? >> >> Yea, I dread those unpredictable power-drops in the middle of nowhere! >> >> Take care, and Good Luck! >
From: JMc on 4 Jan 2010 13:15 There are no codes logged or pending. As an intermittent, it has been very difficult to diagnose, but my brother on holiday visit is convinced it is a crankshaft position sensor. He tells me it is a perfect symptom match on the interruption of ignition, and very easily can explain trouble starting. We (ok he) is not exactly sure of the high-pitch bearing noise, and unfortunately that has not exhibited itself this week. I'll run a tank of gas through after replacement and report back if anyone is interested. Jere "JMc" <mcdonaldjc(a)verizon.net> wrote in message news:hh3m07$7cl$1(a)news.eternal-september.org... > My 1997 4Runner with 203,000 miles has begun exhibiting a strange problem > that seems to be electrical. While driving the engine stumbles, the brake > light on the dash comes on, then in most cases the engine catches again, > the brake light goes out and I drive on. So far it has never actually > stalled the engine entirely, but I've lost power to a dangerous extent. > Often this happens two, three, as many as six times in succession before > it seems to clear. I've noticed a high-pitched small motor bearing noise > from under the hood at about the same time, as though a bearing in perhaps > an alternator or other similar sized unit is wearing out. Ok, I > understand it is an old enough truck that any of these things could be > normal wear and tear, but it is Christmas, and a long weekend till I might > get a chance to have diag codes read. I'm not even sure anything will > have registered. I am most puzzled by the clear connection between the > brake light and the apparent electrical problem. > > Any ideas I might look at tomorrow, any hope that the brake light > indicator is just an indicator that some code is being logged? > > Thanks, > Jere
From: JMc on 6 Jan 2010 13:22 Feels like I can confidently confirm the Crankshaft Positioning Sensor was the source of this problem. A little more obscure than I expected, but at 203k miles, just about anything could be wearing out. This was not cheap, hope to get another 50k miles now. Jere "JMc" <mcdonaldjc(a)verizon.net> wrote in message news:hhtb8o$4jp$1(a)news.eternal-september.org... > There are no codes logged or pending. As an intermittent, it has been > very difficult to diagnose, but my brother on holiday visit is convinced > it is a crankshaft position sensor. He tells me it is a perfect symptom > match on the interruption of ignition, and very easily can explain trouble > starting. We (ok he) is not exactly sure of the high-pitch bearing noise, > and unfortunately that has not exhibited itself this week. I'll run a > tank of gas through after replacement and report back if anyone is > interested. > > Jere > > "JMc" <mcdonaldjc(a)verizon.net> wrote in message > news:hh3m07$7cl$1(a)news.eternal-september.org... >> My 1997 4Runner with 203,000 miles has begun exhibiting a strange problem >> that seems to be electrical. While driving the engine stumbles, the >> brake light on the dash comes on, then in most cases the engine catches >> again, the brake light goes out and I drive on. So far it has never >> actually stalled the engine entirely, but I've lost power to a dangerous >> extent. Often this happens two, three, as many as six times in succession >> before it seems to clear. I've noticed a high-pitched small motor >> bearing noise from under the hood at about the same time, as though a >> bearing in perhaps an alternator or other similar sized unit is wearing >> out. Ok, I understand it is an old enough truck that any of these things >> could be normal wear and tear, but it is Christmas, and a long weekend >> till I might get a chance to have diag codes read. I'm not even sure >> anything will have registered. I am most puzzled by the clear connection >> between the brake light and the apparent electrical problem. >> >> Any ideas I might look at tomorrow, any hope that the brake light >> indicator is just an indicator that some code is being logged? >> >> Thanks, >> Jere >
From: Jeff on 6 Jan 2010 17:09
Thanks for the update! I wonder if a (more readily available) sensor might interchange. A Tacoma is rare in the upullit yards, but a Camry or Lexus are there for the picking. NO error codes! Damn! Any more screaming? JMc wrote: > Feels like I can confidently confirm the Crankshaft Positioning Sensor > was the source of this problem. A little more obscure than I expected, > but at 203k miles, just about anything could be wearing out. This was > not cheap, hope to get another 50k miles now. > > Jere > > "JMc" <mcdonaldjc(a)verizon.net> wrote in message > news:hhtb8o$4jp$1(a)news.eternal-september.org... >> There are no codes logged or pending. As an intermittent, it has been >> very difficult to diagnose, but my brother on holiday visit is >> convinced it is a crankshaft position sensor. He tells me it is a >> perfect symptom match on the interruption of ignition, and very easily >> can explain trouble starting. We (ok he) is not exactly sure of the >> high-pitch bearing noise, and unfortunately that has not exhibited >> itself this week. I'll run a tank of gas through after replacement >> and report back if anyone is interested. >> >> Jere >> >> "JMc" <mcdonaldjc(a)verizon.net> wrote in message >> news:hh3m07$7cl$1(a)news.eternal-september.org... >>> My 1997 4Runner with 203,000 miles has begun exhibiting a strange >>> problem that seems to be electrical. While driving the engine >>> stumbles, the brake light on the dash comes on, then in most cases >>> the engine catches again, the brake light goes out and I drive on. >>> So far it has never actually stalled the engine entirely, but I've >>> lost power to a dangerous extent. Often this happens two, three, as >>> many as six times in succession before it seems to clear. I've >>> noticed a high-pitched small motor bearing noise from under the hood >>> at about the same time, as though a bearing in perhaps an alternator >>> or other similar sized unit is wearing out. Ok, I understand it is >>> an old enough truck that any of these things could be normal wear and >>> tear, but it is Christmas, and a long weekend till I might get a >>> chance to have diag codes read. I'm not even sure anything will have >>> registered. I am most puzzled by the clear connection between the >>> brake light and the apparent electrical problem. >>> >>> Any ideas I might look at tomorrow, any hope that the brake light >>> indicator is just an indicator that some code is being logged? >>> >>> Thanks, >>> Jere >> |