Sunload Sensor failure?

[Guest wally888]

Code 115 set(current), BD 32 data -22(never varies). OAT sensor seems ok.<BR> Resistance of sensor drops as it is heated.<BR> ( I installed new sensor, no change from above)<BR> Black/purple wire is grounded.(pulled, jiggled, cleaned etc, wires, connections)<BR> I cannot locate lt. blue/yellow wire at BCM<BR>or any other place?<BR> Next step??<BR><P>------------------<BR> A recent report said,"Humans only use 20% of their brain." Think what it be like if we used the other 60%!

[Guest Stan Leslie]

Don't know what year you have but I will assume they are about the same. If diagnostic readout for input BD32 stays at -22, this indicates high resistance. If you have access to sensor (top of dash area), remove the sensor and jumper the two pins at the plug. This should cause the BD32 reading to go very high (+120?). If nothing happens and the reading stays low, then the problem is in the wiring between the sensor and the BCM. I think, based on my 91 service manual that the wire goes through a junction block and may change color. It could be a corroded terminal.

[Guest wally888]

Car is 89 and wiring diagram, if I'm reading correctly, shows light blue wire w/ yellow stripe goes from sensor, thru ip/dash connector, to BCM w/o changing color?<BR> Anyone have any idea where junction, IP to Dash, is?

[Guest Stan Leslie]

Sounds like you have a service manual, so it may be easier to locate and get at the BCM than the IP harness junction. By checking an open circuit versus grounding this terminal at the BCM, it would further narrow down whether the problem is the BCM itself or the wiring. If the BCM checks OK, you could check the wire itself from the BCM to the sensor. At that point it might be easier to just run a new wire, bypassing the IP harness.<p>[This message has been edited by Stan Leslie (edited 10-25-2000).]

[Guest wally888]

Stan,<BR> Sounds like a good idea-running new wire-but I can't find the light blue/yellow wire at the BCM!<BR> Does this wire(At the sensor,lt. blue/ yellow), change color before reaching BCM or am I not looking at BCM?<BR> I see box w/ about 100 wires, about 4 plug in's---are there wires on back or top sides also?

[Guest Stan Leslie]

Not sure what you are looking at or where it is your looking. My 91 service manual shows the plug configurations for the BCM with every pin identified. Although I haven't looked, it should also tell you where the BCM is located, so you don't confuse with one of the other computers. Will try to check my manual for more detail when I get time.

[Guest Stan Leslie]

Here's the details for a 91. I suggest you verify in an 89 service manual before proceding. 91 manual, page 8A-50-4, the BCM is located behind the glove box with three large connectors. #1 and # 2 are brown, #3 is red. THe sunload sensor input is in connector #3, position D8 and the wire color is Lt. Blue/Black and does not change color. THe ground side of the sensor is Black/Pink, serves several sensors and also feeds back to the BCM, connector #2, position A1.

[Guest wally888]

Thanks Stan,<BR> Will review 89 manual. My wire color is different than 91 and indicates it doesn't change color. Back to drawing board. Will let you know here where I goofed.

[Guest wally888]

Stan,<BR> Ran new wire, all is O. K.!<BR> The whole endeaver was a learning experience!<BR> I had to make tools to remove Def. Grille and Dash Pad to avoid breaking as, I understand, most of the time they break.<BR> Then I ordered the wrong sensor. Then got the right sensor only to find out the old sensor was good.<BR> Biggest mistake was my looking for wire at ECM not BCM. <BR> The 89 wires are a different color than 91-lt. blue/ yellow from sensor to BCM.<BR> Thanks for help, would never realized my ECM/ BCM mixup if you hadn't answered and would never thought of running new wire either.<BR> WILL DO ELECTRICAL WORK CHEAP!

[Guest Stan Leslie]

Now that you are up and working again, you might want to explore the service manual for the location of that IP harness connector. If that was the source of the problem, it has many more connections which may start dying soon, if it is in an area where it has gotten damp and started to corrode.