Hondata

- Vehicle: Noble M400
- Serial #: xxxxx
- KPro Version: V4.x
- ECU: PRB
- KManager version: V4.x
- Calibration: No calibration, but it's the first option for the PRB ecu for TSX, but with the MAP sensor changed to Hondata 4bar, with a few things changed for Multiplexer, TPS setup for Hall Affect sensor

- Datalog:
noStartMap.kdl = car won't start with the injectors set at 1300cc.
start310.kdl = car will start and idle with injectors set at 310cc, but cannot blip throttle, as it'll stall and die.

- Modified From Stock: Yeah, the entire wiring. Engine harness is from a 04 RSX-S, I used a EP3 harness for the OBD2 plug, C101, and E plug. Wired that up to the ECU and chassis harness.
- When / Where KPRO Acquired: 9/28/2015; HA Motorsports

Problem:
MAP sensor is reading -29psi on ignition on, engine starts and MAP drops to -24.5 psi. This is shown in the start310.kdl datalog.
The noStartMap.kdl just shows me trying to start the engine but never idling.

MAP sensor was tested by my tuner (Pineapple Mike in Vegas). Get continuity from signal wire on MAP to A19 on ECU. Tested voltage for MAP and get 5v, GND continuity, all tested fine.

Using a Hondata 4bar MAP sensor.
Tried with a 2bar GM MAP sensor, no change.
3bar GM MAP sensor, no change.
Unplugged the MAP sensor with ignition on, ECU shows no change in MAP pressure.

Besides a faulty ECU, what else can I check?

Try the ECU in a known working car. You can also try the MAP sensors in a known working car with a known working ECU. If a MAP sensor is wired incorrectly it will damage it and it will have to be replaced.

Spunkster wrote:Try the ECU in a known working car. You can also try the MAP sensors in a known working car with a known working ECU. If a MAP sensor is wired incorrectly it will damage it and it will have to be replaced.

Are you saying the MAP sensor will have to be replaced or the ECU will have to be replaced if wired incorrectly? I ask because we tried three different MAP sensors, ensured the wiring tested ok... same scenario.

I was going to fit the ecu into a friend's car later tonight and see if it reads their MAP sensor, was hoping to find other things to test before I do that though.

thanks for the reply!

Miss wiring will damage the MAP sensor, not the ECU.

Spunkster wrote:Miss wiring will damage the MAP sensor, not the ECU.

Unless something else could cause the MAP sensor reading to be wrong in the ECU (i.e. O2 sensor being wired wrong), it's the ECU.

fitted the ECU to a known working harness and it didn't show the MAP sensor correctly. Double checked his kpro equipped ECU and his showed the MAP sensor.

Is it possible that some other wiring mishap could short out the ECU from reading the MAP sEnsor correctly?

When you tired it on the other vehicle did you upload the calibration that is for that car to the ECU and have the correct setting for the map sensor being used?

Spunkster wrote:When you tired it on the other vehicle did you upload the calibration that is for that car to the ECU and have the correct setting for the map sensor being used?

We did... even did the disconnect/connect the map sensor while the ignition was on and KManager didn't show any change... but it did show a change when we did the same for his ECU.

It sounds like you have defied the odds and somehow damaged the ECU from improper wiring. I would first go through and double check the wiring and make sure you are not using 12v on anything that should be 5v. You will have to replace the ECU as they cannot be repaired.

Spunkster wrote:It sounds like you have defied the odds and somehow damaged the ECU from improper wiring. I would first go through and double check the wiring and make sure you are not using 12v on anything that should be 5v. You will have to replace the ECU as they cannot be repaired.

I'm a go-getter! :)

I did borrow my friend's ECU and plugged into my car. He has a PRB with a V1 of Kpro installed. I'm not sure how different the V1 is to the V4 I have, but with his ECU, the only MAP sensor setting I could get a reading to display that wasn't -29psi was the stock MAP Sensor.
It gave me -29psi, but disconnected, showed +10psi.

I checked continuity for the MAP sensor wiring to the A plug. Here are the tests I performed:
Pin 1 (YEL/RED) to A21
Pin 2 (GRN/RED) to A19
Pin 3 (GRN/WHT) to A11

All good.

Checked voltage between Pin 1 (YEL/RED) and Pin 3 (GRN/WHT), got 5v.
Checked Pin 2 (GRN/RED) for continuity to GROUND, got no continuity... however, this does have continuity to ECU pin A19.

... now what?

By the way, your help is extremely appreciated in all this!

Does that map sensor you tested with work properly on your friend's car?

Spunkster wrote:Does that map sensor you tested with work properly on your friend's car?

Didn't try that, I did order a new MAP sensor just in case the Hondata one failed.

I'm guessing the issue with the harness for the MAP sensor not getting continuity to ground for Pin 2 isn't a problem, as long as it gets continuity to the ECU?

Before plugging another sensor into this car, try the sensor that did not work in the known good vehicle.

As a follow-up, it appeared to be a combination of ECU and MAP sensor.

At some point, I plugged the TPS plug into the Hondata MAP sensor, may have fried it in the process. So, ordered a Omnipower one.
Plugged that in, and my friend's ECU was able to read that correctly, old ECU still wouldn't read it properly, or at least with the drop down settings in KManager.

Swapped ECU, all is well. Was able to get the car tuned, sorta, last night. Now dealing with a VTC gear that won't change angle. Separate issue, separate thread.