Trying to figure out next steps on this. Problem started a couple weeks ago.

The car is a 2010 Honda Accord with about 180k miles.

Couple weeks ago, my wife said the car struggled to start. I looked at the dash and saw no warning lights. I checked the battery and it was a little low, so I replaced it.

I tried starting the car after changing the battery and noticed a green key light flash and a check engine light. When I tried starting it, it would attempt to start but never turn over.

Green light means the car isn’t detecting the correct key. I ran the code and got P2118 which is - Throttle Actuator Control Motor Current Range/Performance

Car has 1 original key and 1 valet key. Both keys had the same result. Would take 6-7 tries before car would actually start.

Here’s what I’ve done:

- I replaced the throttle body and did relearn procedures
- I had an extra key cut and programmed it (been wanting a second one) and this key gives same results as the original and valet.
- I checked the fuses for the ignition and throttle body
- I checked the relay that controls the ignition and all other starting components


I hooked my reader up to read the data as it was idling.

Throttle Position B was at 30% at idle. Range is suppose to be 0-14

Throttle Position D was at 20% at idle. Range is suppose to be at 0-14.

Any ideas on next steps or what I should check?

Appreciate it!

 

The immobilizer system key light has several different outputs. When you turn the key to the II position, but don't try to start the car.

Under normal conditions where the car recognizes the key: The key light will flash once then turn off. When you turn the key to the 0 position, the key light should not turn on.

There are two abnormal conditions where either the key light will keep blinking when the key gets to the II position. When the key is turned to 0, the key light will flash 10 times then turn off. Or the key light will stay on and not flash.

How is your key light behaving?

When you car doesn't start, it is either a no-crank/no-start or crank/no-start. Crank/no-start is when you turn the key to start the car and the starter spins/cranks the engine, but the engine will not run on its own (this is the point where you normally release the key as the engine fired-up and is running). A no-crank/no-start means you turn the key and the starter doesn't spin/crank the engine, so you turn the key and nothing happens.

Are you experiencing a crank/no-start or no-crank/no-start?

 

Thanks for the detailed response!

When I turn the key to the II position, I get a quick green light flash.

When I go back to zero, I get no green key.

I am experiencing a crank/no start scenario.

I’ve noticed, it I go thru the crank/no start sequence about 5-6 times, it will usually start. And then after than it’ll usually start fine unless the car sits for a while again.

Also, for the first time today, once I got the car started today, the check engine light went off. However, I’m still experiencing the crank/no start.

 

So the car is recognizing the key normally. I never notice the normal operation of that key light until I have something go wrong. Then I forget what is normal for the key.

When you get the engine to run, does the car idle normaly or have any other driveablity issues?

Are the starting issues you currently have the same issues your wife had before the battery replacement and/or throttle body replacement?

Sounds like you have an advanced scanner that will help. The honda shop manual says to look at the freeze frame data for the P2118 code. The PCM will store values at the time of the fault, so maybe something will look way off. You can post a screen shot on here too.

What scanner are you using?

The procedure to relearn the idle is to reset the PCM. Start the car with no electrical load like radio, blower, lights, a/c, etc, allow the car to reach operating temperature, then let it idle for 5 minutes. If the radiator fan turns on while idling, this won't count for the idle learn, so check that the radiator fan isn't on the whole time. I'd probably let it idle for 15 minutes just to be sure.

It is strange that you got a code after replacing the battery and sounds like a software/relearn issue. Can you scanner update the PCM to the most current version?

 

I just took my wife out to listen to it start. She said this is the exact same behavior that she experienced.

My scanner is the Thinkdiag OBD2 scanner. I don’t think it’s super advanced. 😊

I admit I’m not the most knowledgeable of the scanner, but I did just look at the freeze frame data and it showed a P062f code on the line that says “DTC that caused required freeze frame data storage.”

When I initially installed the throttle body, it idled oddly but that was before I did the relearn. I did the relearn a few days ago and did the exact method you described. That took care of the odd idle and it now sounds exactly like it always has.

I haven’t taken it for a drive since changing the throttle body bc I didn’t know if it was safe to do so.

 

Since the car is behaving the same way, the items you replaced haven't fixed the orignal issue.

P062f is PCM internal control module keep alive memory (KAM) error. One of the steps in the shop manual is to update the PCM software to the current version. A dealership can do this and independent shops with expensive scanners can do this.

The other item I saw was a bad alternator might cause this problem. What was the bad voltage reading on the battery you replaced? Car batteries are 6 cells each contributing 2.1V, so a full charge is 12.6 V. When you lose one cell, the battery will quickly drop to ~10.5V. If you have a volt meter, test the voltage across the battery with the car off. Turn on the headlights to remove the surface charge and immeditely read the voltage. The voltage should drop by ~0.1V increments.

Then start the car and read the voltage across the battery terminals. The alternator should put out over 13.3V. You can also run a voltage drop test while the engine is running. It is simple. Just touch the black volt meter lead to battery + and the red volt meter lead to the large post on the alternator while the engine is running. The voltage reading should be less than 0.5V. If you have negative numbers, then -0.4, -0.3, etc are good and -0.6 is a bad reading. This is a good first pass at testing an alternator.

A scope that most DIYers do not have is needed for an advanced test like a ripple test.

 

Just got a chance to take a look at the car again.

Did the check you mentioned and the alternator and is showing fine.

The check engine light has gone. No codes now.

I checked the fuel pump fuse and it’s good.

Right now, I have to crank it 4-5 times and then it starts. Could it be a fuel pump going bad? Idk.

here’s a link to me starting it Link to video

 

After the car sits, try turning the key to the II position, but don't turn the key to start the car. Around when the check engine light turns on to do the bulb check, the fuel pump should turn on for about two seconds to pressurize the system. It is a faint buzzing/whirling sound that comes from the back seat, so turn off the radio, blower, etc and listen carefully.

If you hear the fuel pump, then the fuel pump is getting power and running. If not, then you'll have to diagnose further. I suspect you'll hear the fuel pump.

Repeat ~3 more times without trying to start the engine. Then try starting the engine. Let us know if the car starts on the first attempt after priming 3-4 times.

Repeat for the next few days to see if the car starts on the first try after priming 3-4 times.

You can also try letting it prime one time by waiting for the fuel pump to turn off when you turn the key to the II position, then turn the key to crank the engine.

I suspect that the check valve in the fuel pump that maintains fuel pressure at the fuel rail in the engine has failed, and gasoline is returning to the tank. When you attempt to start the car, the pump is filling the lines to the engine, then starting on the 3rd or 4th try.

 

Hello again.

So I did the steps you mentioned above. I tried letting it fulling finish the priming cycle and priming it 3-4 times before starting. Both times the car would crank but not start.

The only way it will start is if I crank it 3-4 times in a row.

I can hear the fuel pump turning in and running.

I really expected the car to start after priming it like this.

Happen to have any other suggestions? I have to end up taking it to a shop.

Appreciate it.

 

Depending on the tools you have, it may be quicker to take it to a good shop to fix the problem.

Since the car eventually starts and runs normally, the compression/timing should be ok. You would have to figure out if you have lack of spark or lack of fuel from the injectors.

There are some DIY items you can try, like cranking the car twice, so it won't start, then pull a spark plug. You can look to see if the plug is soaked with fuel or if you have a strong gasoline smell. That would make fuel less likely, but doesn't completely eliminate it. You can also pull the snorkel from the air filter to the throttle body and have an assistant spray starting fluid directly into the throttle body while you try to crank the car. If the engine runs on its own, then you have some kind of fuel issue.

You can try a spark tester to see if the coils are firing when you first try to start the car.

You'll eventually get to a point where you will either need to connect a fuel pressure gauge to the car which takes different adapters, or really looking at the PCM data to see if a crank/cam position signal is not sending a consistent signal to have the coils fire each spark. Finding a good diagnostic shop will eliminate having parts thrown at it. Just ask the shop if they can return the original part to you, as I've seen vehicles go from shop to shop with multiple new after-market parts that are bad out of the box make diagnosing the original root cause harder.