Test Point 9 - Throttle Switches

THROTTLE SWITCH - IDLE CONTACT
1. Disconnect DME control unit electrical connector.
2. Connect ohmmeter across terminal 2 and ground. Reading should be:

Throttle closed - continuity
Throttle open 1mm - no continuity

3. If reading is not as specified, check wiring between DME and throttle switch and adjustment. If OK, replace throttle switch.

THROTTLE POTENTIOMETER
1. Disconnect throttle switch electrical connector.
2. Turn ignition on and check voltage across harness terminals 1 and 2.

Approx. 5 volts, proceed to step 4.
Not approx. 5 volts, proceed to next step.

3. Check wiring between DME and throttle switch. If wiring OK, replace DME control unit. End of test.
4. Turn ignition off and reconnect throttle switch.
5. Disconnect K/CP control unit electrical connector.
6. Connect ohmmeter across harness terminals 22 and 23.
7. Move throttle slowly to full open position while observing ohmmeter. Readings should be:

Idle position = 320 - 670 ohms
Full open position = 2.7 - 4.7 k ohms

8. If no reading is indicated, check wiring. If wiring OK, replace throttle switch. If reading incorrect or does not move smoothly without fluctuation, replace throttle switch.
9. If reading OK, switch operation normal. End of test.

THROTTLE VALVE CUT-OFF
1. Disconnect throttle switch electrical connector.
2. Using a test wire, jumper harness terminals 4 and 6 together.
3. Start engine and run at approx. 1600 rpm.

Engine should surge

4. If result is not as expected, check wiring. If wiring is correct, replace DME control unit.

FULL LOAD IMPULSE

Test Jack Pin Identification:

NOTE: The full load impulse is generated by the K/CP control unit only after a throttle angle of 65°. To avoid overrevving engine, disconnect 2 fuel injector electrical connectors prior to testing.

1. Start engine.
2. Connect voltmeter across jest jack terminals B and C.

Approx. 5 volts, proceed to step 4.
Not approx. 5 volts, proceed to next step.

3. Check wiring between test jack (if equipped) and K/CP control unit. If wiring OK, replace K/CP control unit. End of test.
4. Open throttle valve fully for a few seconds (do not overrev engine). Observe voltmeter.

0 volts, full load impulse normal. End of test.
Not 0 volts, proceed to next step.

5. Check wiring between K/CP control unit and terminal B of test jack (if equipped). If wiring OK, replace K/CP control unit.