PH1 Continuous Cranking Non-Start

[Szabotage]

Immobilizer & Starter/Cranking:

The primary key prompts normal warning light cycle and initializes the throttle body/fuel pump priming.
The second key (known bad) has always caused the immobilizer warning light to flash quickly.

The second key is also activating throttle body check cycle and allowing continuous cranking (no start).

Is this consistent with how the PH1 immobilizer is supposed to work? From what I understand when the red light flashes quickly, starter should be deactivated.

 

[Szabotage]

What is this grey 5 pin relay on the BMT? All the other relays are 4 pin and pink color.

The manual for the PH1 shows slot "M" should be empty.

 

[Szabotage]

Amended 11/04/2019 - error in testing. Amended this post as don't want to cause confusion. Refer to Post 28 for diagram

Fuel Pump Relay Testing:

87 (Red Color Wire) - Always Live
30 (Thicker Pink Color Wire) - IGN On - Test light ON for couple seconds then cuts off by itself. Cranking, test light comes back ON for couple seconds then cuts off.
86 (Thin Orange Wire) - Same result as 30.
85 (Black Color Wire) - Ignition on/off/cranking - Permanent continuity to ground.

Believe the Pink Color wire on/off with ignition on is the fuel pump priming. There is pressure at the rail.

We think the relay needs a command from the ECU during cranking to power the fuel pump/ignition coils/injectors. Either it's not being provided or is getting cut off. Any ideas?

Thank you!

 

[DaveL485]

Fuel Pump Relay Testing:

87 (Red Color Wire) - Always Live
30 (Thicker Pink Color Wire) - Ignition on but before cranking - Test light ON for couple seconds then cuts off. Cranking, test light ON for couple seconds then cuts off.
86 (Thin Orange Wire) - Ignition on but before cranking - Test Light OFF. Cranking, test light ON for couple seconds then cuts off.
85 (Black Color Wire) - Ignition on/off/cranking - continuity to ground.

Believe the Pink Color wire on/off with ignition on is the fuel pump priming. There is pressure at the rail.

We think the relay needs a command from the ECU during cranking to power the fuel pump/ignition coils/injectors. Either it's not being provided or is getting cut off. Any ideas?

Thank you!

This is a standard relay.

12v Live feeds in to pin 86 and then out of pin 85 through to a switched earth trigger (this will be the ECU). When the switched earth triggers it energises the relay coil.

12v Live also feeds in to pin 30 (either live can be ign or perm, doesn't matter really). With the relay coil OFF pin 87 will see no voltage. With the relay coil ON pin 87 should see 12v if you test it to an earth.
Pin 87 should feed out directly to the fuel pump +ve terminal, then the pump -ve terminal goes to earth.

Plagiarised diagram with some mods.

It should prime when you put the ign on, usually a couple of seconds, then it should be on constantly when the car is cranking or running.

 

[Szabotage]

It should prime when you put the ign on, usually a couple of seconds, then it should be on constantly when the car is cranking or running.

Amended 11/04/2019 - error in testing. Amended this post as don't want to cause confusion. Refer to Post 28 for diagram

Thanks for your reply.

Your description/diagram is what i am familiar seeing normally. With our car, we are finding:
87 is 12+ perm Live.
85 is perm Grounded.
30 receives voltage for a couple seconds with IGN, then shuts off by itself. Cranking receives voltage but shuts after couple seconds.
86 same as 30

My interpretation:
30 is connected to the fuel pump (+). On IGN; 86 receives a temporary 1-2 second command signal and activates the relay to power 30. The pump receives voltage from 30 to prime. Priming cuts off and stays off. Upon Cranking 86 reactivates the coil and 30 receives power from 87 but is 1-2 seconds. As daveL485 suggests, this signal should be on constantly when cranking or running.

Activation is either getting the command cut off or missing voltage signal and relay disconnects.

Something is happening to deactivate the coil from 86. (Tested 85 with a multi meter, revealing always continuity to ground.)

 

[ed_harland]

I guess we are talking about the fuel pump relay here ? If so the pump relay is fine.
So the injection lock or injection relays are not firing up.
The injection lock relay should give 12v at the inj. ecu, connector C, black plug, terminal L3 if it does the relay and immobiliser would seem ok. (ignition on).
Then terminal H4 on the same ecu plug should be live when cranking which activates the injection relay.
I would maybe bridge the injection relay which should power up the injectors, coils etc. and maybe start it up, at your risk !!!
I would guess it's one of these relays.

 

[ed_harland]

Just been having a read up and see that the injection relay referred to, is actually the fuel pump relay !

 

[Szabotage]

Just been having a read up and see that the injection relay referred to, is actually the fuel pump relay !

Ed, Thanks. I came across the same description from a renault manual, while searching the web but was not able to verify which model the info pertained to. Having said that, i think this is accurate because we are unable to locate the "INJECTION RELAY". The PH2 v6 manual wire diagram shows a separate injection relay.

Re-Posting amended Fuel Pump Relay diagram & Injection Lock Relay Diagram:

Fuel Pump Relay receives a voltage command on 86 to activate to power 30. It does so and primes for 1-2 seconds @ IGN on then auto switches off until Cranking. At Cranking relay is activated, powering the fuel pump but this is momentary, lasts 1-2 seconds . It almost seems like the ECU does not know it's cranking/run, and signals to prime. What would cut off the signal like this?

Ignition LOCK Relay
87 Live 12v+ Live Permanently
86 Live 12v+ Live Permanently
85 Ground Signal/Trigger - Grounds Coil to activate Relay. @ IGN off, no continuity to ground. IGN on, 950ohms. @ Cranking, 890ohms. After Cranking/IGN on, and IGN off, 950ohms 3-4 seconds delay before switching itself off.
30 When IGN & Crank - 12V on and stays on. IGN off, 950ohms 3-4 seconds delay before switching itself off.

The ECU is making commands to this relay via ground.

Ground isn't strong according to Ohm reading so this may be the reason fuel pump relay is unable to stay activated. Having said that it's strong enough to activate the relay as detailed. Does the ground signal going back to the ECU need to be better than 950ohms?

Test:
Would running a permanent ground wire to 85 Ignition Lock Relay be advisable? And would this be a reliable test? Bridging to ground with a test lamp, activates the inj. lock Relay. Yet to run a true ground to test while cranking.

Summary: Injection Lock Relay seems to be activating as expected, a ground, albeit very weak ground is activating the relay. 950ohms is quite low and a weak ground signal. Is this what is causing the fuel pump relay to drop 12V signal to activate at cranking? And is the delay ground signal cut after IGN off normal?

Thanks!

 

[Szabotage]

What is this grey 5 pin relay on the BMT? All the other relays are 4 pin and pink color.

The manual for the PH1 shows slot "M" should be empty.

Info on Slot M on BMT.

 

[Szabotage]

So the injection lock or injection relays are not firing up.
The injection lock relay should give 12v at the inj. ecu, connector C, black plug, terminal L3 if it does the relay and immobiliser would seem ok. (ignition on).
Then terminal H4 on the same ecu plug should be live when cranking which activates the injection relay.
I would maybe bridge the injection relay which should power up the injectors, coils etc. and maybe start it up, at your risk !!!
I would guess it's one of these relays.

Immobilizer Test:
Will test for 12V, connector C of ECU terminal L3 @ ING on and post results. I presume the inj lock relay term 30 to provide this signal, will check for continuity to L3_C also.

ECU to Fuel Pump/Injection Relay:
Will also test H4, connector C of ECU for 12V going to the fuel pump/injection relay. I believe this is the signal that's getting cut off @ cranking.

Injector Testing Results:Is this a normal result?
Key OFF Position - 3V at both terminals
IGN On - One terminal stays 3V. The other terminal goes from 3V to 12V for 1 second then back to 3V.

 

[Szabotage]

We had a no ECU (CEL) connection detailed in posts [v6plaque]13[/v6plaque] & # 17. Found there to be an intermittent 10Amp fuse to be the culprit. This is the fuse board in bonnet next to fuel pump relay. Does anyone know what fuse this is for? It's a temporary 7.5 fuse here. I believe it powers the BMT. Hopefully that'll be the end of our intermittent issue.

 

[Szabotage]

Video of Center Dash Display Flashing

Sometimes it stays on normally but other times it can flash constantly like in the video. Is this a symptom of bigger issues going on with the BMT?

 

[DaveL485]

I do bridge relays to earth to simulate "on" when testing, with both OE and standalone ECU's. I also have a bit of wire with 2 spades so I can pull a relay out and bridge the contacts to eliminate relay faults.

 

[Szabotage]

I guess we are talking about the fuel pump relay here ? If so the pump relay is fine.
So the injection lock or injection relays are not firing up.

Am treating the injection & fuel pump relay(s) as the same in one for the PH1.
Yes both injection lock and Fuel Pump relays activate. But something is cutting off power during cranking to both relays.

The injection lock relay should give 12v at the inj. ecu, connector C, black plug, terminal L3 if it does the relay and immobiliser would seem ok. (ignition on).

Test results below. All appears to be normal at the ECU terminal but something is interrupting voltage to the injection lock relay at crank.

Then terminal H4 on the same ecu plug should be live when cranking which activates the injection relay.

H4 is indeed receiving 12V as detailed below. But something is causing the fuel pump relay to de-activate after a second of cranking.

I would maybe bridge the injection relay which should power up the injectors, coils etc. and maybe start it up, at your risk !!!
I would guess it's one of these relays.

What size fuse would you recommend for the bridging? Hesitant on trying this until understand what is interrupting voltage to both relays @ cranking.

Thank you!

--------------------------------------

Amended Test Results:

* Sorry - Below info is an edit April 14th. Previous results not correct, was looking at connector wrong way around. Have deleted/amended below.

M4 Connector C - Power Earth - Continuity to Chassis. Ground to ECU OK.

Injection Lock L3 terminal of Connector C (black) (Thick White / Orange stripe)
- Before IGN cycle - 0V
- IGN On - 12V Live
- Cranking - 9V (starter turning)
- IGN Off - 12V for few seconds delay, then 0V

Injection/Fuel Pump H4 of Connector C (Thin Orange)
- Before IGN cycle - 12V Live
- IGN On - 12V drops to 0V for a second then back to 12V.
- Cranking - 12V drops to 0V for a second then back to 9V for as long as cranking.
- IGN Off - 12V Live

Thanks in advance!

 

[Szabotage]

Connector C @ ECU
Orange Wire - H4 is permanently live but looses voltage for a second with IGN On. At cranking, voltage disappears for a second then comes back as long as starter is turning.

Fuel Pump Relay
Orange Wire - 86 signal receives voltage for a second then deactivates with IGN On. At cranking voltage returns for a second then deactivates.

H4 is supposed to be feeding the injection/fuel pump relay. What else is between these 2 points which can cause the above?
Should H4 be permanently live and what would cause it to momentarily loose voltage at IGN On & Crank?
How does the ECU control fuel pump priming?

Thank you!

 

[DaveL485]

You should have 12v live at injectors and fuel pump when it's cranking, and I think the injectors should be live with ign on but the fuel pump primes for 3 secs with ign on and then goes off with the 12v reactivation on crank and run.

 

[ed_harland]

Looking at your ammended test results in post [v6plaque]34[/v6plaque] I'm wondering if the 9 volts is too low on cranking, the ecu may 'see' this as a problem.

 

[Szabotage]

Looking at your ammended test results in post [v6plaque]34[/v6plaque] I'm wondering if the 9 volts is too low on cranking, the ecu may 'see' this as a problem.

Tried with a new batt and with jumper attached. When starter turns, it draws down. 10V-11V was the best I could produce. So that rules out the batt.

Something is turning 12V to 0V at connector C momentarily @ IGN & Crank - When 0V happens, at the same time the fuel pump relay receives voltage momentarily, then looses at the same time connector C regains 12V. What are possible explanations that can cause this?

What else does the ECU look for besides the following before "seeing" a problem and shutting things down?
- Immobilizer
- low voltage/amp

...?

Happy Easter BTW

Thanks

 

[Spike]

Not that it helps but, the gap to the reluctor ring should be about 15 to 20 thou or max of 0.5mm (20thou) i have had problems with non specific sensors not working then a genuine Bosch or Marreli works.
IMHO i think you will work it through but i feel that scanning for fault codes is a waste of time, it tells you what happened and not whats happening. get a good scanner that can display four or more inputs and watch the screen, if the ECU is getting the signal it WILL be displayed and therefore work and visa versa. Battery voltage is critical and constant cranking can push the volts too low, run a big slave battery whilst testing or a dedicated charger with about 70a capacity to keep the volts up.

Good hunting.

 

[ed_harland]

Not that it helps but, the gap to the reluctor ring should be about 15 to 20 thou or max of 0.5mm (20thou) i have had problems with non specific sensors not working then a genuine Bosch or Marreli works.
IMHO i think you will work it through but i feel that scanning for fault codes is a waste of time, it tells you what happened and not whats happening. get a good scanner that can display four or more inputs and watch the screen, if the ECU is getting the signal it WILL be displayed and therefore work and visa versa. Battery voltage is critical and constant cranking can push the volts too low, run a big slave battery whilst testing or a dedicated charger with about 70a capacity to keep the volts up.

Good hunting.

Yes keep the volts up.
It's still looking like it doesn't know the engine is turning and we keep coming back to the crank sensor.
You need to get Renault Clip plugged in for proper diagnosis.