2000 Ex P1668 No Start
Thread Starter
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Cross-Country
Joined: Jan 2021
Posts: 60
Likes: 5
From: South Florida
2000 Ex P1668 No Start
The truck is usually our road tripper to haul the kids and dogs. We hadn’t driven it in a few weeks so I was going to take it to work to run it and I got a crank no start and the SES light came on.
I hooked up forscan when I got home from work and I got the P1668 code. I did the following:
- unplugged the fuel heater - nothing
- swapped the relays around with the blower/horn- all of them worked.
-fuses under the hood were good.
-no injectors buzzing on the buzz test- Tac was jumping though during the test
- I ended up fussing with the fuse under the steering column, it was not blown, but I pulled it and re set it and did another buzz test that was successful, cleared the codes, no codes. And she started up.
fast forward 5 days. I did an oil change this morning, went to start after and nothing. P1668 code again. Swapped the inside fuse that cured me last time and still nothing. no injectors buzzing on the buzz test- Tac was jumping though during the test. IDM is less than a year old.
Am I expecting it to be the PCM? If the PCM were bad, would I have more codes (or a failure to read completely?)
EDIT: I did comb through other threads, Including the most recent one on page one with no luck.
I hooked up forscan when I got home from work and I got the P1668 code. I did the following:
- unplugged the fuel heater - nothing
- swapped the relays around with the blower/horn- all of them worked.
-fuses under the hood were good.
-no injectors buzzing on the buzz test- Tac was jumping though during the test
- I ended up fussing with the fuse under the steering column, it was not blown, but I pulled it and re set it and did another buzz test that was successful, cleared the codes, no codes. And she started up.
fast forward 5 days. I did an oil change this morning, went to start after and nothing. P1668 code again. Swapped the inside fuse that cured me last time and still nothing. no injectors buzzing on the buzz test- Tac was jumping though during the test. IDM is less than a year old.
Am I expecting it to be the PCM? If the PCM were bad, would I have more codes (or a failure to read completely?)
EDIT: I did comb through other threads, Including the most recent one on page one with no luck.
It's a Van Gogh
Joined: Feb 2010
Posts: 7,812
Likes: 1,335
From: Elk Grove, CA
So same symptoms and code. Which fuse # fixed it last time?
Per the DTC list: P1668 PCM-IDM diagnostic communication error, Open/shorted EF or FDCS, open IDM ground.
Slap in a new fuse for starters. Maybe the fuse holder is weak, not gripping the fuse well?
Might as well look at the harness under the 42 pin connector for shorts.
Per the DTC list: P1668 PCM-IDM diagnostic communication error, Open/shorted EF or FDCS, open IDM ground.
Slap in a new fuse for starters. Maybe the fuse holder is weak, not gripping the fuse well?
Might as well look at the harness under the 42 pin connector for shorts.
Fleet Owner
Joined: Jun 2004
Posts: 25,090
Likes: 1,112
From: Rio Rico, AZ.
The truck is usually our road tripper to haul the kids and dogs. We hadn’t driven it in a few weeks so I was going to take it to work to run it and I got a crank no start and the SES light came on.
I hooked up forscan when I got home from work and I got the P1668 code. I did the following:
- unplugged the fuel heater - nothing
- swapped the relays around with the blower/horn- all of them worked.
-fuses under the hood were good.
-no injectors buzzing on the buzz test- Tac was jumping though during the test
- I ended up fussing with the fuse under the steering column, it was not blown, but I pulled it and re set it and did another buzz test that was successful, cleared the codes, no codes. And she started up.
fast forward 5 days. I did an oil change this morning, went to start after and nothing. P1668 code again. Swapped the inside fuse that cured me last time and still nothing. no injectors buzzing on the buzz test- Tac was jumping though during the test. IDM is less than a year old.
Am I expecting it to be the PCM? If the PCM were bad, would I have more codes (or a failure to read completely?)
EDIT: I did comb through other threads, Including the most recent one on page one with no luck.
I hooked up forscan when I got home from work and I got the P1668 code. I did the following:
- unplugged the fuel heater - nothing
- swapped the relays around with the blower/horn- all of them worked.
-fuses under the hood were good.
-no injectors buzzing on the buzz test- Tac was jumping though during the test
- I ended up fussing with the fuse under the steering column, it was not blown, but I pulled it and re set it and did another buzz test that was successful, cleared the codes, no codes. And she started up.
fast forward 5 days. I did an oil change this morning, went to start after and nothing. P1668 code again. Swapped the inside fuse that cured me last time and still nothing. no injectors buzzing on the buzz test- Tac was jumping though during the test. IDM is less than a year old.
Am I expecting it to be the PCM? If the PCM were bad, would I have more codes (or a failure to read completely?)
EDIT: I did comb through other threads, Including the most recent one on page one with no luck.
Thread Starter
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Cross-Country
Joined: Jan 2021
Posts: 60
Likes: 5
From: South Florida
Thanks for the advice all. Sorry for the break in updates. I was able to get a working IDM to check if it was that and it started right up and the codes are cleared.
This would make the 3rd IDM since I’ve owned it. The original that was in it when I got it that I changed at 370,000.
This one made it 5,000 miles. Cardone Re-man.
When the first one went out, I was getting the P1316 code and lost power to half the injectors. This time it was the P1668 and no start at all with the IDM fried.
I am going to look through the harness to see if there are any shorts either way, but could it just be bad luck that I got a crappy IDM? Or should I expect a short is zapping them somewhere?
This would make the 3rd IDM since I’ve owned it. The original that was in it when I got it that I changed at 370,000.
This one made it 5,000 miles. Cardone Re-man.
When the first one went out, I was getting the P1316 code and lost power to half the injectors. This time it was the P1668 and no start at all with the IDM fried.
I am going to look through the harness to see if there are any shorts either way, but could it just be bad luck that I got a crappy IDM? Or should I expect a short is zapping them somewhere?
FTE Leadership Emeritus
Joined: May 2014
Posts: 27,351
Likes: 5,945
From: Lake Hartwell, GA
You likely just received a typical unreliable remanufactured IDM. I would suggest Jonathan at DTC (https://www.dieseltechchatt.com) for your next IDM. He also does repairs on faulty units if you have time.
A visual inspection of the harness is a good idea.
Good luck to you!
A visual inspection of the harness is a good idea.
Good luck to you!
Thread Starter
|
Cross-Country
Joined: Jan 2021
Posts: 60
Likes: 5
From: South Florida
You likely just received a typical unreliable remanufactured IDM. I would suggest Jonathan at DTC (https://www.dieseltechchatt.com) for your next IDM. He also does repairs on faulty units if you have time.
A visual inspection of the harness is a good idea.
Good luck to you!
A visual inspection of the harness is a good idea.
Good luck to you!
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