15-06-2018, 04:29 PM
Tried the disconnect battery, ignition set to run, reconnect method to reset immob. No change.
Removed the connector that feeds the 4 wires into the back of the pump. From the harness to the connector the wires are coloured white, red green and green/yellow. They change colour from the connector to the pump. The inside of the connector was spotless, no dirt, corrosion.
The circuit diagram in the Haynes for the NAD late 97 shows 4 wires with the above colours going to the 'pump unit - anit theft'.
It describes the wires as follows:
White - Anti start
Red - Anti start
Green - Oil pressure switch
Green/yellow - ground.
Now another diagram shows the oil pressure switch as an open switch to ground. I assume switch is normally open, and when pressure is high enough switch closes and signal is grounded (but I could be wrong!).
Why would oil pressure be used in anti theft?
While cranking, the oil pressure light is on for a few seconds, then goes out. So I assume the switch is operating OK.
I measured the voltage on the 4 wires in the harness side of the connector, with ignition on and off (but not cranking).
Wire Ignition on Ignition off
White 11.4 11.7 (battery volts = 12.5)
Red 12.3 0.06
Green 0.03 0.0
Green/yellow 0.01 0.0
If the Green wire is from the oil pressure switch, it is showing close to 0V when no pressure, so perhaps the switch is normally closed and opens when pressure high enough ?
Unfortunately I don't have a multimeter that measures current via magnetic field coil, as that might tell me if solenoid is being switched or not.
Took key transponder pick up coil off steering column. Lifting cover I can see a PCB with contacts to the coil. All I could do was buzz out the coil. It gave a low resistance, so not open circuit.
Tried to trace wires from pick up module, but they disappear into loom and behind facia.
No sign of an ECU behind battery. There are some relays. One controlling vacuum for the EGR valve I think. Then there is the glowplug control box and another relay.
I tried my Lexia thing some time ago when the airbag light wouldn't go out. I never got it to communicate with the car.
Removed the connector that feeds the 4 wires into the back of the pump. From the harness to the connector the wires are coloured white, red green and green/yellow. They change colour from the connector to the pump. The inside of the connector was spotless, no dirt, corrosion.
The circuit diagram in the Haynes for the NAD late 97 shows 4 wires with the above colours going to the 'pump unit - anit theft'.
It describes the wires as follows:
White - Anti start
Red - Anti start
Green - Oil pressure switch
Green/yellow - ground.
Now another diagram shows the oil pressure switch as an open switch to ground. I assume switch is normally open, and when pressure is high enough switch closes and signal is grounded (but I could be wrong!).
Why would oil pressure be used in anti theft?
While cranking, the oil pressure light is on for a few seconds, then goes out. So I assume the switch is operating OK.
I measured the voltage on the 4 wires in the harness side of the connector, with ignition on and off (but not cranking).
Wire Ignition on Ignition off
White 11.4 11.7 (battery volts = 12.5)
Red 12.3 0.06
Green 0.03 0.0
Green/yellow 0.01 0.0
If the Green wire is from the oil pressure switch, it is showing close to 0V when no pressure, so perhaps the switch is normally closed and opens when pressure high enough ?
Unfortunately I don't have a multimeter that measures current via magnetic field coil, as that might tell me if solenoid is being switched or not.
Took key transponder pick up coil off steering column. Lifting cover I can see a PCB with contacts to the coil. All I could do was buzz out the coil. It gave a low resistance, so not open circuit.
Tried to trace wires from pick up module, but they disappear into loom and behind facia.
No sign of an ECU behind battery. There are some relays. One controlling vacuum for the EGR valve I think. Then there is the glowplug control box and another relay.
I tried my Lexia thing some time ago when the airbag light wouldn't go out. I never got it to communicate with the car.