Help! Trouble Codes P0102, P0113, P0118, P0123 (and P2118)

Overview:
Ok Tacomaworld, I was hoping the group-think around here could help me out. My father has a 2016 4Runner (Trail Premium) that he was washing after a splendid trip to Colorado. He was spraying down the engine bay and now the truck is stuck in limp mode. It runs rough, not above ~2000rpm, and it smells rich. A local shop that specializes in Asian makes had the truck for a while and couldn't figure out the issue. They replaced the throttle body and that seemed to fix one code but they were otherwise of no help. (The tech also failed to bolt down the airbox, fusebox, and didn't clip the interior trim around the glovebox correctly so I'm not too impressed with their work.) Currently, the 4Runner is at home and I'm slowly working on diagnosing things but I'm a bit baffled. Any help or ideas would be much appreciated, thanks in advance.

The Issues:
P0102 - Mass Air Flow Circuit Low
P0113 - Intake Air Temperature Circuit High Input
P0118 - Engine Coolant Temperature Circuit High Input
P0123 - Throttle/Pedal Position Sensor/Switch "A" Circuit High Input
P2118 - Throttle Actuator Control Motor Current Range/Performance (seems to be fixed with a throttle body replacement)

What I've done so far:
I'll admit I'm a nobody when it comes to this stuff (a mechanical engineering student in uni), but I'm trying my best here. Please be nice lol.

I've been operating under the assumption that there are 3 possible issues here: the ECU/ECM, the sensor(s) in question, or the wiring in between.

1. The shop replaced the throttle body and actuator assembly and that seemed to fix P2118. But for a couple $k I could've done that myself thank you.

2. So far I have swapped in another ECU to no avail. Nothing changed and I doubt both ECUs are bad.

3. I've swapped the throttle pedal for a different one, and nothing changed. I pulled up techstream and I got the following values with a battery voltage of 12.148V.

At 0% throttle, Sensor 1 Voltage was at 15.6% and Sensor 2 Voltage was at 32.1%
At 100% throttle, Sensor 1 Voltage was 69.8% and Sensor 2 Voltage was at 85.4%

According to the TIS RM I should get this:


So the voltages the ECU is getting back from the pedal are way high? Not sure what to make of that. I can't really tell how the pedal works but is it pegged off of a reference voltage? Could that be too high?
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4. With the engine off the MAF is reading 0.75 gm/sec which is within the 0.93 g/sec limit specified by the RM while in that state. No leads here? I do have another MAF on the way cause it's relatively cheap that I'll swap in.

What I'm planning on doing:
1. I've got the pinouts for the connectors to the MAF/Coolant Temp Sensor/Pedal/Throttle Actuator/ECU from the EWD. I'm planning on checking each for open circuit and short-circuit conditions.

2. I'd like to check the ECU's ground circuit. However, I'm not quite adept yet at reading Toyota's EWD yet and I wasn't really sure which pins ran to ground. For example, if I see an image like this does that mean pins 15,11,10,16, and 18 on connector B39 run to ground connector B2 (in the engine bay)? And how do I interpret codes like E02, ME01, etc.? Am I even barking up the right tree? The RM mentions this as part of the electronic circuit inspection procedure.



3. I think I'll go through and check all the grounds in the engine bay and in the "instrument panel". I have the diagrams for those printed out as well.

Again any suggestions or help would be greatly appreciated! Thanks!

 

You said all issues started at the same time so why not start with the easiest thing to get to which is the MAF/IAT sensor. Unplugged IAT should read -40, plugged in it should read within 10 degrees of ambient temp with the vehicle cold.
If it doesn't then check with a meter set to volts DC from Pin 1 (Yellow) to battery negative (should be 5v with the key on) and from Pin 2 (White/Red) to battery negative (should be 0v) and then to battery positive (should read battery voltage).

 

Following

 

Thanks for the reply! I got 59F for intake air, my kestrel was showing 57.1F ambient. Unplugging the MAF/IAT I got -40F. I checked pins 1 and 2 anyway and got 5V, 15mV, and 12V as you would expect.

Question of curiosity (I'm trying to learn) how do you know what those pins should be doing under different conditions? Looking through the RM and EWD I couldn't find any data or information like that.

 

That's interesting but it's still got a P0113 as current?

I don't really have time to go in depth on it right now as I'm at work but I've learned over time how to reverse engineer wiring diagrams.
Most sensors on a vehicle are 5v sensors, 2 wire sensors like temp sensors should have 5v on the signal wire when unplugged and the other wire is Sensor Ground. 3 wire sensors like pressure and position sensors have a 5v ref that should be 5v at all times, a sensor ground, and a signal wire that may be pull up or pull down.

 

Yes, I cleared the code and it came back. I swapped the MAF sensor assembly as well and it still came back. In fact, I think P2118 is back and I might have a new code; P0453.

There's gotta be a common denominator here. However, swapping ECUs didn't fix the problem. The 5V reference seems solid. I did a continuity check on the harnesses to the MAF and the pedal and they seem fine. I visually inspected the grounds B1 and B2 on the engine block and they seem fine.

Here's a screenshot of techstream:

 

They are listed as Permanent codes not Current or Pending, the P2118 and P0453 are showing as Pending and Current so we need to attack those.

Permanent codes can not be cleared with a scan tool or battery disconnect, they will self clear after the monitors for those codes run and pass during 2-3 consecutive drive cycles (note a drive cycle is not an ignition cycle).

Give me a bit, I gotta shower and eat and I'll look up those codes and see where we need to go.

 

I just looked this up, Have you checked the ETCS Fuse (10A)? It's not uncommon for that fuse to blow on Toyota's with a weak/dead batter/jump start and it will cause the P2118 code if it's blown/missing.

 

Yep, I checked. It's a good fuse and it's in the right location.

 

Since you have Techstream go into the ECM data list and see what +BM VOLTAGE is reading, it should read the same as battery voltage.

 

Ok might've found something. +BM Voltage was 0.039V. A new code as well, P2138.

 

Let's address the P2118 code first, let me find the ECM pins we need to check.

 

Ok so we need to check for Power on Connector B38 Pin 23 (Pink/Blue) and Ground on Connector B9 Pin 10 (White/Black).

 

I'm getting 0.9V on B38/pin23.

Good connection to ground on B39/pin10.

 

Ok verify you have good power at the ETCS fuse just to make sure we aren't chasing our tail, meanwhile I'll track down the locations of the 2 harness connectors (FA2 & and BF2).

 

Need to backprobe and check FA2 Pin 16 (Pink/Blue to Pink) and BF2 Pin 4 (Pink to Pink/Blue).





Looks like FA2 is behind the left kick panel.


BF2 looks to be behind the glovebox.

 

Studying the wiring diagram further I kind of suspect you may find green crusties in one or both of those connectors, the APP sensor wires go through FA2 (P2138) and the EVAP pressure sensor (P0453) wires go through BF2 as well as the ECTS power wire.

 

I have good 12V at the fuse.

Well, I haven't probed anything yet. I was trying to figure out which junction/connector FA2 is but I think I found the right one.

 

Dang green crusties, I called it lol.
Providing no pins are corroded off hopefully it will clean up with some electrical cleaner/DeoXIt.

Next thing is to find the water leak, if it has a sunroof the first thing I would check is the drains.

In any case I'm gona head off to bed, I'll check back in tomorrow.

 

I'll try to clean it off tomorrow. Would you recommend any agitation with a soft brush, say something like nylon?

The truck does have a sunroof, for the past couple years, it has been covered by a GFC tent that was recently lifted off. I know correlation ≠ causation but as soon as I saw that I thought sunroof drains as well.

Again, thanks so much for the help! I'll report back what happens tomorrow. Cheer!