KOER Code 18/ Low Idle
#1
KOER Code 18/ Low Idle
I've got a 1991 F150 with the 4.9. I recently bought a code reader and checked for koeo codes. I found one for egr and o2 so I fixed those 2 issues now then got the code 11 for system ok. Then I ran the KOER test and got a code 18 r for the spout. So I replaced the tfi and I took it down the road, ran pretty except for slight hesitation when taking off and a choppy low idle about 700 rpm. It's still throwing the code 18 and the spout is connected. Wondering what the next thing to check would be?
Last edited by Antrim1992; 06-13-2018 at 07:35 PM.
#2
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Scanners for these trucks are notoriously UNreliable - they frequently display spurious codes & vague or irrelevant definitions. I recommend you return it for refund, and use a simple jumper wire, as shown here:
(phone app link)
Don't pick a word or part name out of a code definition. When you post a code, post the whole number and the COMPLETE definition. Codes do NOT mean to replace parts - they only indicate where to BEGIN diagnosis. The diagnostic procedure for this fault is in Haynes Ch.5, Sec.5 or 7 (depending on which edition you get). It requires a digital multimeter, some jumper wires, pierce probes, and patience.
(phone app link)
Since you now know that the ICM wasn't the problem, I recommend you put the original back. It's probably higher-quality than the new one (which you might still be able to return for refund).
(phone app link)
Don't pick a word or part name out of a code definition. When you post a code, post the whole number and the COMPLETE definition. Codes do NOT mean to replace parts - they only indicate where to BEGIN diagnosis. The diagnostic procedure for this fault is in Haynes Ch.5, Sec.5 or 7 (depending on which edition you get). It requires a digital multimeter, some jumper wires, pierce probes, and patience.
(phone app link)
Since you now know that the ICM wasn't the problem, I recommend you put the original back. It's probably higher-quality than the new one (which you might still be able to return for refund).
#3
The old tfi looked pretty nasty on the inside. Looked like it had gotten some moisture in it because the board had rust in several points. The one I swapped for it came off of a parts truck that I have with lower miles and same year. Parts truck was a great investment lol. I'll try out the jumper method to see if I yield different results. If not Ive got a Haynes laying around and a multimeter. I'll post my results asap.