Operation CHARM: Car repair manuals for everyone.

Powertrain Controls - ECM/PCM


Chart Trans System Voltage Low:




Circuit Trans System Voltage Low:





CIRCUIT DESCRIPTION
The internal electronic components of the transaxle have specific optimum temperature operating ranges in which they best perform. As trans fluid temperature rises, components such as shift solenoids heat up and their internal resistance rises. This effect will demand higher voltages to allow correct operation of these devices. Similarly low temperatures require less voltage for correct operation.

Diagnostic Trouble Code (DTC) 96 Will Set When: Minimum voltage sensed at the ignition feed is as follows:

^ -40°C (-32°F) = 7.3 volts
^ 90°C (194°F) = 10.3 volts
^ 150°C (304°F) = 11.4 volts
^ Engine speed must be above 1000 RPM for 2 seconds to set DTC 96.

Action Taken (Powertrain Control Module (PCM) will default to): All devices will become disabled causing transaxle to default to 3rd gear. The Malfunction Indicator Lamp (MIL) will not illuminate.

DTC 96 Will Clear When: A current DTC 96 will clear when the voltage that caused DTC 96 rises 1 volt.

A History DTC 96 will clear after 50 consecutive ignition key cycles without a current DTC 96 being stored.

TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.

Minimum voltage allowed for DTC 96 to set is on a graduated scale and will change with temperature.

Minimum voltage at:

^ -40°C (-40°F) = 7.3 volts
^ 90°C (194°F) = 10.3 volts
^ 150°C (304°F) = 11.7 volts

1. This test checks for normal battery voltage between 9-15 volts.
2. This test checks if the low voltage display is due to the generator, CKT 439 or PCM. If the voltage is less than 8.6 volts, the PCM is OK.

DIAGNOSTIC AIDS
CKT 439 supplies ignition voltage to the PCM.

If DTC 96 sets when an accessory is operated, check for poor connections or excessive current draw.