Hello all,
Trying to find out if a p1607 code that keeps recurring is definitely an ecu that needs to be replaced, or if there’s a chance that it just needs to be cleared.

If weather is cold, when the car is started, it’s in limp mode. If it sits running, or I drive it, after 15 minutes or so, I can shut it off, remove key, restart and it runs fine. If I shut off and it sits for a half hour, it wilts start and run fine. If it sits long enough to get cold, it’s back to limp mode.
In the summer, it went for weeks and was fine…. If it drops below 40 overnight, it’s back to limp mode.

Appreciate any advice. Car is an 01 Spa that I’ve had for 18 years and put 130,000 miles on. Aside from tires and one set of brakes, it’s been so trouble free, I haven’t needed to learn much about repairs. Time to spend some time and $ getting her back tiptop.

Mike

 

Hey Mike - I have a 2002, with 84K miles, and I am experiencing the same symptoms - trips a P1607 code when it's cold. Were you ever able to resolve the issue?

I had my ECU / ECM repaired and it did not seem to make a difference.

Thanks - John

 

Did y'all run thru the steps starting on Page 11-93 of the Service Manual? According to the manual this code is unique to the "AP1" cars (before 2004).

Cold weather makes me suspect an intermittent connection or connector somewhere in the circuit since John had his repaired and the fault is still there. Or even a low battery can trigger it.

Try this Google search (without the quotes) "P1607 site:www.s2ki.com".

-- Chuck

 

Hey Chuck,

I appreciate your taking the time to reply.

I was able to run through the starting steps on Page 11-93, several times with mixed results.
- When it is cold out, it terminates with me having to borrow a known-good ECM, indicating that the existing ECM is bad.
- When it is warm out, it terminates with an intermittent failure.

I checked, as well as AutoZone, the battery and the charging system, and both are fine, well within specs.

I have not had to replace the battery in several years and I have never had to jump start it.

Out on honda-tech.com, Targa250R mentions that "The P1607 is likely being caused by a bad trace or solder joint on the circuit board inside the PCM. In cold temperatures,
the components can contract and cause the trace or joint to pull apart, which causes a break in the circuit."

I am starting to think he might be onto something.

Previously, I mentioned that I did have my existing ECM repaired by UpFix. I don't suspect that they tested it under cold or cooler conditions. I am going to reach out to
them and see if there is anything else I can do.

If you have any additional ideas, please let me know

Again, I appreciate your replying.

Thanks - John

 

John (& Bing) --

Bing, you still here? Been a year. If you are recommend you PM each other and exchange phone numbers and emails. Conversation works better than text or email for me.

Cold testing seems like the next step. Along with tracing all the wiring to the ECU and making sure the contacts in the connectors, the weak point in any electrical circuit, are clean and not corroded. DeoxIT can work wonders on connections.



My S2000 battery doesn't last more than 3 years but she's only driven occasionally and never in cold temperatures.

-- Chuck

 

Dang, 3 years is terrible on a battery. Battery tenders are your friend I am over 8 years on my current battery from NAPA, and 6 of that was sitting through MN winters (so not driven or even started from Nov till late April unless I needed to move it out of the way). It sits on a tender every winter. Gets driven about 2000 miles a year besides track use.

 

I have seen this code twice. Both needed an ECU.

I likely have one on the shelf.

 

Hey, doing some research on the forum as my FIL and i are having the exact same symptoms with his MY00 Ap1 S2k. After lots of experimenting and testing weve pinpointed it down to this 8 pin EEPROM located on the front of the ECM board. Applying heat via a hot air station and turning on the car makes it work as normal. We are currently trying to figure out how to read whatever information is on the chip and transfer it to a new one.

On the board it is labeled IC9 and the chip model is "93LC46B". I am unsure of what the chip does, however I do know that the ecu reads whatever is on it during startup and let's it run normally. So long as its not power cycled, nothing changes.

Very curious as to what insight you or anyone else may have on it.

 

Is that EEPROM look original to the board? To my blurry eyes the solder joints look more hand soldered than machine. It's a 25¢ chip (probably in quantities of 1000! )

Tried resoldering that chip to the board? Might cure some tiny electrical gap. I'm still thinking it's a trace on the board... (Grasping at straws here!)

-- Chuck

 

Yes, the chip is original. This car is a 2 owner with sub 40k miles. But the solder joints look like that because we previously tried resoldering it to the board, which unfortunately did not solve the issue. But heating the chip has been the only success we've gotten so far