Pinpoint Test H: Overdrive Cancel Switch Not Working
Test Step
H1 CHECK INPUT TO PCM
- Key in OFF position.
- Disconnect: PCM C175a.
- Key in ON position.
- Measure the voltage between PCM C175a pin 41, circuit 8 -TA21 (WH/GN), harness side and ground.
- Is the voltage greater than 10 volts?
Result / Action to Take
Yes
REFER to INFORMATION, GAUGES & WARNING DEVICES .
No
GO to H2.
Test Step
H2 CHECK FOR VOLTAGE TO FUSE 205 (5A)
- Key in ON position.
- Measure the voltage between primary junction box fuse 205 (5A) input pin and ground.
- Is the voltage greater than 10 volts?
Result / Action to Take
Yes
GO to H3.
No
REPAIR the circuit. TEST the system for normal operation.
Test Step
H3 CHECK FOR VOLTAGE INPUT TO THE SHIFTER
- Key in OFF position.
- Disconnect: Transmission Shift Selector C307.
- Key in ON position.
- Measure the voltage between transmission shift selector C307 pin 7, circuit 15-TA21 (GN/BK), harness side and ground.
- Is the voltage greater than 10 volts?
Result / Action to Take
Yes
GO to H4.
No
REPAIR circuit 15-DA5 (GN/OG) or 15-TA21 (GN/BK). TEST the system for normal operation.
Test Step
H4 CHECK CIRCUIT 8 -TA21 (WH/GN) FOR SHORT TO GROUND
- Disconnect: PCM C175a.
- Disconnect: Transmission Shift Selector C307.
- Measure the resistance between transmission shift selector C307 pin 6, circuit 8-TA21 (WH/GN), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Result / Action to Take
Yes
GO to H5.
No
REPAIR the circuit. TEST the system for normal operation.
Test Step
H5 CHECK CIRCUIT 8 -TA21 (WH/GN) FOR AN OPEN
- Key in OFF position.
- Measure the resistance between PCM C175a pin 41, circuit 8 -TA21 (WH/GN), harness side and transmission shift selector C307 pin 6, circuit 8-TA21 (WH/GN), harness side.
- Is the resistance less than 5 ohms?
Result / Action to Take
Yes
INSTALL a new shifter harness. TEST the system for normal operation.
No
REPAIR the circuit. TEST the system for normal operation.