'01 t & c: cluster warning lights 'on'/gauges 'out'

QuestionEdit

QUESTION: Roland,

Same minivan that you helped me with the P0122, P0106 & P1496 5V supply codes last week. Tracked that problem to a short in the leads to the MAP sensor where the wires appear to have been contacting the intake manifold.

ABS/Brake light is still coming on intermittently and my wife and nanny have both had all of the warning lights come on and stay on for anywhere from a few seconds to a few minutes. Brake fluid level appears fine. The minivan continues to run when the warning lights come on.

Doing the key dance the only codes present are the ones from last weeks issue (that I haven't had reset).

Am I looking for another wiring harness issue? If so where? What else could be causing all of the warning lights to come on.

ANSWER: Hi Seth, That is interesting...there is no single wire to the cluster that would cause all the warning lights to go 'on' except possibly the white/violet pci bus (digital data lead) from the diagnostic port pin 5 that is under the dash by the steering column (where you can plug in the code reader) that goes to pin 9 of the instrument cluster plug. It may be due to a fail-safe feature of the cluster which causes all the lights to go on when something goes wrong inside, but if that pci bus wire were 'open' you would also loose the gauge readings. So please list exactly which warning lights come 'on' and which lights don't come on, and which gauges work, and which gauges don't work in this situation. That may give a clue to the possibility that a wire from the powertrain controller or the body computer which also go to the pin 5 at the diagnostic port might be the problem. Another thing to do is a cluster self-test: With the ignition off, press and hold the trip reset button. Hold it pressed until the word "Sof" appears in the odometer window, then release the button. Then watch to see if any 4-digit number replace the "Sof" and if so let me know. If "end" appears, that means those are the fault codes, or there is nothing wrong with the cluster. I haven't heard of this before, so it may be a failure inside the cluster itself. Please 'rate' my answer (see below). Thanks, Roland

---------- FOLLOW-UP ----------

QUESTION: I asked the nanny when I got home. All the warning lights came on. All the gauges including the speedometer went to off scale low.

I haven't had a chance to check the digital data lead, but the cluster self test yielded a ton of codes:

100.0 100.1 100.2 100.3 100.4 100.5 100.6 200.6

AnswerEdit

Hi Seth, Those codes all say that the digital data information from the entire digital data bus 'system' is not being 'seen' at the cluster. It might be the white/violet wire itself is 'open', but more likely I would believe is that the connection between pin 9 of the cluster socket and the circuit board of the cluster have become a 'cold' solder joint (i.e. no connection). I would remove the cluster, open it up and touch the solder joint between the pin 9 connector and the circuit board with the tip of a heated soldering pencil so as to repair the joint. Of course once you get the cluster out you can check that the pin 9 of the plug is connected to pin 5 of the diagnostic port socket which if patent would indicate that the problem is not with the wire between the port and the cluster but rather inside the cluster. Then reheat the solder joint of the cluster's circuit board at pin 9 connection which should repair the problem. To remove the cluster: disconnect the battery - post clamp, remove the over steering column bezel by lifting straight up wit a firm pull, remove 4 screw holing in place cluster bezel, tilt steering column to full down position, pull rearward on the cluster bezel to release and remove it, remove 4 screws holding insturment cluster to instrument panel, rotate top of cluster rearward to gain access to plug, remove plug from cluster, remove cluster from panel. Install is the reverse. Please "rate" my answer. Thanks, Roland