Engine Control System

DIAGNOSTIC CHART

Diagnostic Chart:

Diagnosis
Vehicle speed sensor 2 does not function.
Harness connector between ECM and vehicle speed sensor 2 is shorted or open.

Trouble Symptom
Poor idling, poor driveability, engine stalls.

CHECK VEHICLE SPEED SENSOR 2

VSS Test:

1. Remove combination meter.
2. Measure resistance between connector terminals of combination meter by turning speedometer with a small screwdriver inserted in the cable hole.

Terminals Resistance
No. 11 - 8 10 ohms max. <> 1 M ohms min.
(four times per rotation)


CHECK HARNESS CONNECTOR BETWEEN ECM AND VEHICLE SPEED SENSOR 2

Harness Test:

1. Turn ignition OFF.
2. Unplug connector from ECM.
3. Measure resistance of harness connector between ECM and combination meter.

Connector & Terminal Resistance
(E29) 4 - (i18) 8 10 ohms max.

Harness Test:

4. Measure resistance of harness connector between ECM and body to make sure there is not a short.

Connector & Terminal Resistance
(E29) 4 - body 1 M ohm min.


CHECK GROUND CIRCUIT OF VEHICLE SPEED SENSOR 2

Ground Circuit:

Measure resistance between combination meter and body.

Connector & Terminal Resistance
(i18) 8 - body 1 M ohm min.