QuestionThe dealer has replaced the TCM and the PCM. I replaced the speed sensors and the harness and completed the instrument panel check. The P0500 and P1698 codes are fresh. The problem is so intermittant, that the dealer has not been able to repeat it and run the DRB check, it clears by the time they get me in. I am getting the codes from a code reader. Could this be a ground wire problem?
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-----Question-----
On our 99 Breeze the transmission will shift into low range with the shift indicator lights on all gears at the instrument panel and the speedometer goes to "0". This happens very infrequently. It will come back to "normal" as suddenly while driving or you will have to shut off and re-start to clear the problem. We have changed the TCM, the PCM, the speed sensors, the wiring harness from the transmission to the TCM, checked the instrument panel with the self diagnostic check and the problem remains. Weather and temperature do not have an effect on the problem. The check engine light gives the following codes: P0500, P1698, and P1739. Please help.
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Hi Mike,
That intermittant must be disconcerting. You certainly have changed all the major suspect parts. I wonder if the codes are fresh or stale? You might want to disconnect the battery for a few minutes to be sure and then watch for the return of new codes. Disconnecting the battery will generate a P1684 so ignore that one. Then see of the 0500 and 1698 return after the next malfunction.
The 0500 is for the speed sensor and the 1698 is for an absence of the bus messages from either trans or the engine computer on the bus. I can't find what the 1739 means.
It certainly seems like the speed sensor or its signal is getting lost, if the code is fresh. And the 1698 would indicate a problem with communication on the bus, and if the harness is good then some analysis using the DRB III might yield some info on why there is a failure on the bus.
Has the DRB III been put on the vehicle at a dealership? Has the dealership done all the parts replacements or are the do-it-yourself projects? Sometimes the modules need to have data input for them to match with the vehicle.
It may be that you will have to await a more permanent collapse when the DRB can look at the vehicle in the malfunction condition.
Those are my thoughts on the situation. Let me know the answers to my questions and we'll work on it some more.
Roland
AnswerHi Mike,
If they are getting the code for the tps voltage being out of the normal range then that may be relevant because both the engine and the trans need that signal to operate properly. The only caveat I have is that according to a mid-90's trans manual that code shouldn't cause a limp in, but maybe the protocol was modified later in the 90's to put the trans into limp-in with that fault. The TPS is very easy to replace, it is just screwed into the throttle body so the labor should be minimal as should the part. So I would authorize the repair and see what happens. Or you could buy the TPS and replace it yourself. I'll be interested to know how this works out.
Roland
Hi Mike,
Well we are on the same page on this. I wonder about the 1739, have you been able to find anything? I would have expected to find it in one of my manuals.
On the ground wire: there are two grounds for the systems in question, one is on the left strut tower, the other is on the driver's side kick panel, just in front of the door opening. So you might want to remove, clean, and tighten those. Other than watchful waiting about, the only other approach would be to flex the harnesses while a helper watches the dash for any warning lights.
The 0500 and loss of speedo signal is interesting: you might wonder if the replacement output speed sensor is faulty. Or better yet, check the wiring between the sensor and the tcm plug (dark blue/brown to pin 13, light green/violet to pin 14) and maybe flex the harness while you check the continuity.
Please let me know when you figure out why this is happening.
Roland
