W T E C I I I E L E C T R O N I C C O N T R O L S T R O U B L E S H O O T I N G M A N U A L
Before troubleshooting, read Paragraph 56. Also, check the following:
Fluid level, using dipstick
ECU input voltage
Other diagnostic codes
The following procedure is to find the cause for an OLS problem. The procedure is sequential. Follow
the procedure until the cause for the OLS problem is found and repaired. Once the problem is found
and repaired, STOP. For example, if the problem is fixed in step 3, there is no need to continue to the
1. Disconnect the external wiring harness at the transmission feedthrough connector. With the igni-
tion ON, verify there is 5.0 VDC between the OLS power and ground pins (see page D10) on the
external harness connector. This is to verify that power and ground are getting to the OLS. If the
5.0 VDC is not present, check the wiring for the OLS power and ground circuits (wires 124T9
and 135T25, respectively). If there are no wiring problems (opens, shorts-to-ground, shorts-to-
battery), and if the 5.0 VDC is present, go to Step 2.
2. Observe the OIL LEVEL COUNTS on the DDR while jumpering the OLS power pin to the OLS
signal pin. If the count jumps from 0 to 250+, the OLS signal line is good and the ECU function is
good. Continue to Step 3. If the count remains at zero, locate and repair problems in the wiring of
OLS signal (wire 165T26). If there are no wiring problems, and the count still remains at zero,
the ECU may be bad. Go to Step 5.
3. If all checks prior to this have been normal, the problem is either in the OLS itself, the internal har-
ness wires or the transmission side of the feedthrough harness connection. Inspect the transmission
feedthrough harness connector to be sure that the OLS power, ground and signal pins are not loose
or out of position. Correct any connector problems found. Reconnect the external harness to the
transmission feedthrough harness connector. See if Code 14 12 recurs before continuing to Step 4.
4. Consult the appropriate transmission Service Manual for proper procedure and remove the control
module from the transmission. Remove the OLS from the channel plate. Reconnect the external
harness to the transmission feedthrough connector, if not done in Step 3. With the ignition ON, ob-
serve OIL LEVEL COUNTS on the DDR. With the OLS in normal position, the count should be
835. Invert the OLS and the count should be 192255. If the counts are abnormal, replace the
sensor. Check the new sensor in both normal and inverted positions. If the counts respond cor-
rectly, the problem should be resolved. Attach the new OLS to the channel plate and reinstall the
control module using the appropriate transmission Service Manual for proper procedure.
5. Replace the ECU. If replacing the ECU corrects the problem, reinstall the original (bad) ECU to
confirm that the problem is in the ECU. If the original ECU now works, inspect the ECU connec-
tors for any corrosion or damage which may cause an intermittent condition. If the original prob-
lem recurs, reinstall the replacement ECU.
CODE 14 XX OIL LEVEL SENSOR (OLS) (Figure 53)