Mazda 5 2008-02 CR: MAF sensor changed, still MAF problems

1)
All lights (except Xenon) have been blinking since day 1 or at least several years.

2)
Few weeks ago I started to hear screaming noise and smell of the burning metal => alternator's freewheel were broken and I changed the alternator including the freewheel.
Still all lights (except Xenon) blinking, the voltage varies between 750..1000 rpm 13.50..14.12 DCV / 0.44 ACV.

3)
Right after the alternator change the engine started to behave badly:
* Poor idle & engine stall
* Engine drags
* Delay in acceleration / Rough acceleration
* Engine light and TCS light
The engine starts easily.

Fast test:
*PUl13 ~Intake air temperature sensor: (too) high voltage
*PO102 ~MAF sensor: (too) low voltage

*Battery and charging OK

Battery poles and connectors carefully cleaned and installed.

Using jump-start cable I tested that there were no contact problems between
* engine <> battery minus pole <> chassis <> engine
* alternator plus pole <> battery plus pole <> fuse box plus pole <> alternator plus pole

Fuse box was dirty, mostly sand & dust, I did clean it with "PRF Contact Cleaner".
I did check all fuse & relay contacts and also big C-02 connector contact, all ok, no oxide / corrosion / rust.

Old MAF sensor contacts and the MAF sensor cable contacts were like new.

Using "CRC Air Sensor Clean PRO" I tried to clean the MAF sensor carefully: no result.

Using starting fluid spray I tried to test if there is "in take" leaks on any pipe and hose by spraying it a lot all over
=> there engine did not rush even slightly.
(Spraying directly to intake as small amount as possible did rush engine nicely.)

Using iCarsoft JP V2.0 tester I found out that MAF sensor readings varies about 0.20 .. 3.10 V continuously, especially on idle.

It varies less with 3000+ rpm.
Temperature sensors values were constant and reasonable.
MAF sensor reading constant when engine stopped.

With new, exactly same, sensor same problems and values.

I tried to shortcut wiring between MAF sensor and fuse box connector C-02, one wire at the time, to find out if there is broken wire causing problems but no result.

Noticed that "pressure control unit" probably making much more noise than earlier, like sneeze, don't remember it has done it earlier, but the other hand there has not been many problems so maybe I have not noticed it before.

The new MAF sensor were already broken?

Main relay?
Looks like new but haven't tested (and it must be tested in use, not separately).

Ignition lock?
Haven't test it yet.

Engine PCM / ECU box broken?
When the alternator's freewheel went broken it may have caused overvoltage situation and broken some electric components?
How to test?
No codes with tester.

The cable between fuse box connector C-02 and Engine PTC / ECU module?
Haven't test it yet, will be hard job to do.


Any hints?

Of course wiring diagrams (and workshop manuals etc.) would help a lot but haven't found any for this diesel engine.

(Some harms have had because car has been taken into use 22 months after manufacturated: battery, tires, shock absorbers, rubber parts,..).

Mazda 5 (CR19) 2.0 CD (RF)
JMZCR19R680nnnnnn
Manufactured 2008-02
Taken into use 2009-12
105 kW / 143 hp / 360 Nm


140.000 km
87.000 miles


MAF Denso DMA-0113
https://www.google.com/search?q=dma-0113+denso



Update 2020-01-17:
I went to Bosch Car Service and I got excellent service directly from the technician:
* First I told problems, all what I have done and what were results
* We end up a consensus what test should be done (in a 25 min what was left in technicians work day)

Results:
* Alternator, charging and battery were all ok.
* EGR did function logical: it opens and closes when it was driven with the tester, verified by sound and the sensor readings
* There were some fault codes which were logical.
=> MAF sensor probably ok although the values were irrational
=> Needs more time to investigate.

Possible source of the problem:
* Turbo’s solenoid
* Somehow leaking fuel somewhere which causes uncontrolled need of more air to burn this leaked fuel
* EGR can otherwise broken than electrically

Update 2020-01-17:
Second diagnose report from Bosch:
(5.6 h 588 eur)

Error code from MAF.
* Engine stalls on idle, clicking noise from throttle valve body / EGR

When disconnecting throttle valve body actuator OR EGR valve connector the engine does not stall on idle.
* No error code from MAF but from disconnected device

MAF signal wavy regarding what devices disconnected.

Alternator voltage measured using oscilloscope
* Slightly wavy but should not effect to MAF

Following components voltage
* MAF
* Manifold pressure controller
* Lambda sensor
* Crank sensor
* Cam sensor
* Throttle valve body actuator
* EGR valve
=> Only throttle valve body actuator supply voltage drops

So I still does not have any idea what is causing problems (and how to fix it).
Does anyone have any documents what kind signals goes to those engine's actuators: On/Off, PWM, Current/Voltage?




Last edited by Mz5Petu; 2020-02-19: Update the second Bosch Car Service visit.