Hello and welcome to Just Answer!
So, when you turn the key to the start position, the starter doesn't engage and crank the engine over is that correct?
Can you remove the starter relay from the fuse box in the engine compartment and jump terminal 30 to 87 and see if the starter cranks the engine over. Do this with transmission in park and key off. The cover should show the location of the starter relay.
The relay terminals are numbered on the terminal side.
yes it cranks over. excuse the delay. i am on a home pc and car is at different location
No problem! I am having site issues, so if I don't respond it is because of the site.
Did the vehicle quit on the road and not re-start or did it just not start one day?
Did it start and stall three times and now not turn over?
i was at a garage and i took out a spark plug that i have had problems with fouling out due to oil laying on top of it. i took the plug out then turned it over to blow the oil out and it turned over then wouldnt.. i replace the plug and wire then tried to start it and it would not crank. thought it was the starter so replaced it and found it was not. has never occurred in past. have 140k miles on car and do service and most repairs myself.
With the relay removed, can you use a test light(not a multimeter) and test terminal 85 and 86 for power, while someone holds the key in the start position. There should be power at one, it doesn't matter which one. Mark the one that has power. If there is power, I need you to hook your test light alligator clip to the positive battery terminal and test the terminal that didn't have power. This is testing the ground side of the relay control.
Test this wire with the key on and let me know what you find!
i did as you instructed and there was neither power or ground in either 85 nor 86 when the key was held in start position. i checked the test light and found power at 30 also
i have power in the yellow wire when the key is engaged. i do not have when it is not.
That wire does not change color. The yellow wire from the switch feeds the starter relay terminal 85 or 86, it can be either one. There is no fuse in between!
There is a connector in between the switch and relay and you could check for power there. The connector is under the dash and is white. There are 2 connectors side by side that connect your instrument panel wiring to the engine compartment wiring.
Check to make sure there is nothing spliced into the yellow wire under the dash.
If you have a break in the wire, we will have to find the break, by tracing that yellow wire.
I would turn the fuse box upside down and inspect the yellow wire. Make sure it isn't pushed out of the box.
Let me know, once you test this and I will try and help you isolate the problem.
Can you tell me if the round red security led in the cluster stays on after the key has been on for 10 seconds, or flashes?
It sounds like you have a problem with the sentry key immobilizer system or the PCM.
If the PCM doesn't see a valid message from the SKIM after 6 times trying to start the vehicle, it will disable the starter relay ground driver until the problem is repaired.
Let me know!
Fault code P0688 is a fault for the auto shut down relay circuit. This code has nothing to do with the no crank condition.
How did you get the code, do you have a code reader or did you read it off the odometer with the key cycle method?
Can you check fuse # XXXXX(20 amp) in the fuse box in the engine compartment?
Click this link for the diagram. http://senduit.com/97acb7
It sounds like you have a bad PCM!
I guess the next step would be to verify we have power and ground to the PCM.
Can you disconnect the PCM connectors and test some terminals for me.
I can let you know, which ones to test if you want to do this!
Click this link to download the PCM pinouts http://senduit.com/786247
When testing insert a small paper clip into the terminals so you don't spread them with your test light probe. Test all the wires that have battery and ignition power and all grounds. To test the ground just hook your test light to the positive battery cable and test the ground terminals.
Battery power is live at all times and the fused ignition power needs to have the key turned on.
Let me know if you have any questions, I will be online for quite awhile tonight.