Roadmaster Estate Wagon V8-305 5.0L (1991)
TEST DESCRIPTION: The numbers below refer to circled numbers on the diagnostic chart.
1.
Checks for a closed switch to ground in the park position. Different makes of "Scan" tools will read Park/Neutral differently. Refer to operators
manual for type of display used for a specific tool.
2.
Checks for an open switch in drive range.
3.
Be sure the "Scan" tool indicates drive even while wiggling the shifter to test for an intermittent or mis-adjusted switch in drive.
DIAGNOSTIC AIDS:
If the vehicle does not have power door locks, before replacing the P/N switch or ECM, check the diode in circuit 1545 for a short condition. The diode
is located between P/N switch and the rear glass release relay.
