Persistant ECT Code 117
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From: St. Peter
Just an FYI. At my school, I'm being taught that instead of taking a resistance reading, a voltage drop reading is more accurate. So instead of disconnecting the PCM and the ECT and doing a resistance reading, you should leave them connected, turn the meter to volts, and backprobe the wire at the the ECT, and backprobe at the PCM, the reading should be around 0 volts, a reading larger than 0 (say 2 volts) would indicate there is a voltage drop in the wire.
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From: Lewistown, PA
Well, I drove the truck home from work (33 miles) and not once did the CEL light or did the truck try to stall.
When I got home I checked for codes, just to be doubly sure. All good.
I'm not sure if it was corrosion on the PCM pins or the bolt holding the connector in being loose, but issue seems to be resolved now. When I pulled the PCM connector, there was some whitish pasty stuff on the pins. The brake cleaner washed it off.
Thanks for your help pawpaw & R031Kona!
When I got home I checked for codes, just to be doubly sure. All good.
I'm not sure if it was corrosion on the PCM pins or the bolt holding the connector in being loose, but issue seems to be resolved now. When I pulled the PCM connector, there was some whitish pasty stuff on the pins. The brake cleaner washed it off.
Thanks for your help pawpaw & R031Kona!
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Posting Guru
Joined: Apr 2004
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From: Lewistown, PA
Just an FYI. At my school, I'm being taught that instead of taking a resistance reading, a voltage drop reading is more accurate. So instead of disconnecting the PCM and the ECT and doing a resistance reading, you should leave them connected, turn the meter to volts, and backprobe the wire at the the ECT, and backprobe at the PCM, the reading should be around 0 volts, a reading larger than 0 (say 2 volts) would indicate there is a voltage drop in the wire.
Postmaster
Joined: Aug 2003
Posts: 2,873
Likes: 0
From: St. Peter
Just an FYI. At my school, I'm being taught that instead of taking a resistance reading, a voltage drop reading is more accurate. So instead of disconnecting the PCM and the ECT and doing a resistance reading, you should leave them connected, turn the meter to volts, and backprobe the wire at the the ECT, and backprobe at the PCM, the reading should be around 0 volts, a reading larger than 0 (say 2 volts) would indicate there is a voltage drop in the wire.
Also on this note, there must be power running through the circut when doing this. You wont get a reading if there is no current flowing through the circut, so in your case it should be done with the engine running. Or if you are doing voltage drop tests on a battery terminal, you should have the headlights on, or any other load that would make power flow through the battery terminal.
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From: Lewistown, PA
Thanks for the tips Peter94
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