No Gear Shift to 4th Gear

No Gear Shift to 4th Gear

Symptom Description

TCM does not shift to 4th gear under any of the following condition.

- "3" position switch signal is inputted.
- 4L/N switch (if equipped) is turned ON. (4L or N mode)
- TCM detects the following DTCs.
DTC P0602, P0722, P0752, P0757, P0962, P0963, P0973, P0974, P0976, P0977, P1702, U0073 and/or U0100

Troubleshooting

WARNING:

If you do not select a suitable route and take proper precautions when performing a road test, an accident can occur.

- Select a level road with no traffic to minimize the risk of accident.
- Perform the test extremely carefully.
- Perform the road test using 2 persons, a driver and an assistant.

1.
Was "A/T System Check" performed?
YES -
Go to Step 2.
NO -
Go to A/T System Check A/T System Check.

2. Check DTC

Is DTC P0602, P0722, P0752, P0757, P0962, P0963, P0973, P0974, P0976, P0977, P1702, U0073 or U0100 detected?
YES -
Perform DTC Flow to repair and retry.
NO -
Go to Step 3.

3. ECT check

Warm up engine to normal operating temperature.
Check ECT monitored by TCM using scan tool.

Is ECT indicated -40 °C (-40 °F)?
YES -
Go to Step 4.
NO -
Faulty ECT sensor, its circuit or engine cooling system. If OK, substitute a known-good TCM and recheck.

4. "3" position switch signal inspection

With ignition switch ON, check voltage between terminal "E93-9" of TCM connector and ground under the following conditions.

"3" position switch specification
Shift selector lever to "P", "R", "N" or "D" range: 2.9 - 3.8 V
Shift selector lever to "3", "2" or "L" range: 1.4 - 2.0 V

Is result as specified?
YES -
- For vehicle equipped with 4L/N switch, go to Step 5.
- For vehicle equipped without 4L/N switch, substitute a known-good TCM and recheck.
NO -
Faulty "3" position switch or its circuit. If OK, substitute a known-good TCM and recheck.

5. 4L/N switch signal inspection

With ignition switch ON, check voltage between terminal "E93-4" of TCM connector and ground.

4L/N switch specification
Transfer gear position "4H": Battery voltage
Transfer gear position "4L" or "N": 0 - 2 V

Is result as specified?
YES -
Substitute a known-good TCM and recheck.
NO -
Faulty 4L/N switch or its circuit. If OK, substitute a known-good TCM and recheck.