Chart 7A-20A-1: O/D Off Indicator Does Not Light
Diagnostic Chart:
Overdrive Switch Circuit:
Circuit Description:
When the "OVERDRIVE" Switch button is released a signal is sent to the PCM. When the PCM receives this signal, it lights the "O/D OFF" Indicator in the instrument cluster informing the driver that the transaxle will not shift into overdrive. If the button is depressed the PCM receives a signal, the "O/D OFF" indicator goes out and the transaxle is permitted to shift into overdrive when appropriate.
Test Description: Numbers below refer to circled numbers on the diagnostic chart.
1. This checks to see if the "O/D OFF" Indicator will light by jumping the switch to ground.
2. This determines if the ground circuit is faulty and checks for a faulty "OVERDRIVE" switch.
3. This checks for an open LT GRN wire or open indicator bulb.
4. This determines which part of the ground circuit is faulty, WHT/BLK wire or junction block 3.
5. This checks for an open WHT/BLK wire or for faulty junction connectors 1 and 3.
Diagnostic Aids:
Check GAUGE Fuse for opens, and grounds for clean and tight connections.
Check for poor connections at component and inline harness connector terminal connections before replacing components. After repairs have been made, repeat the PCM OBD System Check to ensure system is functioning normally.