URQ MAC12

["DRoxburgh" <DRoxburgh@email.msn.com>]

So do I do nothing with the pins marked 'Chassis' or should they have a
ground wire to the inlet maniold as well??

TIA

Daryl
>

> I am just about to run a new ground from the ECU to the inlet to try and
> resolve the intermittent WOT operation. Look at the SJT A-T web page it
> seems that (using the SJM numbering) pins 9, 18, 34 are all grounds. I am
> not sure about 23 which states ' Air Temp sensor & Hall sensor ground
> return', or 2, & 5, which state chassis.

> Rather than blow the whole thing up, or miss the important wire, any
> suggestions?
>
> BTW, colour codes dont seem to help as there are brow wires every where.
>>
>>MAC12 ECU pin assignments
>>Viewing the connector with the prongs on the right and  the side locating
>lugs al at the top, the upper left pin is Pin 1, with numbering proceeding
>along the connector to Pin 18 at the top right. The bottom row is also
>numbered from left to right, from
>>19 to  35.
>>
>>1.   Blue/Wh   Cold Start Valve (N17)
>>2.   Br/Ye     Inlet manifold ground
>>3.
>>4.
>>5.   Br/Ye    Inlet manifold
>>6.
>>7.   Mauve     Idle  Stabiliser (J142), Oil
>>                   Pressure Warning Controller
>>8.   Blue/Bl   Frequency  valve  (N7)
>>9.   Br/Red    Chassis
>>10.  Blue      Coolant Temperature
>>                       (G62 - side  of block)
>>11.  Blue      Engine RPM  (G28)
>>12.  Mauve     Ignition Timing (G4)
>>13.  Red          Ignition Timing (G4)
>>14.  Blue/Wh   Electronic Thermoswitch
>>                          (F76)
>>15.  Br        Knock  (G61)
>>16.  Wh        Knock  (G61)
>>          Br        (shield for above)
>>17.
>>18.  Br/Ye     Chassis
>>19.  Gr/Ye     Wastegate Control  (N75)
>>20.  Grey      Idle Switch (F60), Idle
>>                        Stabiliser (J142)
>>21.  Br/Red    Fuel Pump Relay (J17)
>>22.  Gr/Wh     Electronic   Ignition
>>                          Power Stage (N70)
>>23.  Br        Inlet Air Temperature  (G42)
>>        Br/Red    Hall Sensor (G40)
>>24.  Blue        Hall Sensor (G40)
>>25.  Red/Bl    Hall Sensor (G40)
>>26.  Wh        Full Load Switch (F81)
>>27.  Gr        Hall Sensor (G40)
>>28.  Br        Shielding for 11, 12, 13, 29
>>29.  Grey      Engine RPM  (G28)
>>30.
>>31.  Bl/Wh     Fuel pump relay
>>                          fuseholder
>>32.
>>33.
>>34.  Br/Ye     Chassis
>>35.  Bl/Red    Power via Fuse (S34, 10A)
>>
>>--
>> Phil Payne
>> Phone: 0385 302803   Fax: 01536 723021
>> (The contents of this post will _NOT_ appear in the UK Newsletter.)
>
>