88-89 Mark1 Sc Clutch Troubleshoot tips

[mr2tim]

You won't find this stuff in any books and our Toyota dealer sez all the Mark1 Technicains have died off....so here goes

How to troubleshoot your non-working Toyota Mark 1 SC Clutch and dash light indicator.

Apply battery Voltage to Clutch wires to visually confirm clutch is working (clutch will move in and out)

Confirm SC relay is working per page sc-19 of the Service Manual

Check relay ground point “E” at the intake manifold.

ECU Input Signals-what to check for (based on page 42 Elect Manual)

Magnet operation- engine revs are monitored by input from

1. Rpm signal in the Distributor
A.) Terminal G-1-page IG-8-140-180 Ohms
B.) Terminal G-2- “ “ “ “ “

2. Throttle Signal System
A.) Terminal VTA-page FL-98 -3.3-10k ohms (Throttle open)

3. STA Signal (Starter motor input)
A.) Terminal STA to E1 or E2-6-12 volts ( Ignition Switch on at start position and clutch in or a/t in neutral))

Supercharged Light Operation
(Indicates SC clutch is working)

Check these input Signals

1.) Perform Check #1 above (Distributor Signal)
2.) Terminal Vs (Air Flow Meter)-page FL-30 VS-E1 or E2-6-9 volts (Ignition Switch on and Measuring plate fully open)
VS-E1 or E2-2-8 volts (Ignition Switch on @ idle)

PM me if you need more guidance mr2tim ( I have pictures to help)