Transmission Controls With PCM

Diagnostic Chart:

Diagnostic Chart (Cont'd):

Circuit Schematic:

2ND GEAR ACTUATOR CIRCUIT GROUNDED/OPEN
2nd clutch is applied when circuit 1222 is opened at the PCM. When the PCM opens the circuit, the voltage is monitored at terminal J3F2 to check for proper circuit conditions.

INFORMATION FLAG PARAMETERS
Information flag 71 is set when the PCM has detected the following condition twice per ignition cycle.
- Voltage monitored at terminal J3F2 (circuit 1222) is less than 2 - 2;5 volts when the 2nd gear actuator is switched off electrically by the PCM.

TEST DESCRIPTION
Numbered steps below refer to numbered steps on chart.
1. This step verifies problem is stilt present.
2. If the TRS 2/TCC fuse is OK, check for battery voltage on fuel pump relay side of fuse with engine running or with PCM in diagnostic mode.
3. This step check's for a ground in circuit 1526. A ground in circuit 1526 will cause the TRS 2/TCC fuse to fail and set information flag 71.
4. A faulty actuator or connector plate could have blown the TRS 2/TCC fuse. This step checks for low resistance.
5. An open in circuit 1526 will cause information flag 71 to set. Check circuit 1526 for opens.
6. This step determines if fault is in the circuit to the PCM or in the actuator or connector plate.
7. This step will determine if fault is in the actuator or connector plate.
8. An open or a ground in circuit 1222 will set information flag 71. This step checks circuit 1222 for opens or grounds.

DIAGNOSTIC AIDS
When attempting to diagnose an intermittent problem use the Scan tool[1] to review supplemental diagnostic information. The supplemental data can be used to duplicate a problem.

- This information flag may set or intermittent 2nd gear starts may be caused by a poor electrical connection at either the PCM, actuator connector plate or UHJB terminals. Wiggling connectors while performing an actuator quick test may help isolate the problem area.

Check the tightness of the female terminal grip with a spare male terminal.

When the PCM detects a fault in the circuit (open, ground, short) the PCM will open the circuit internally to protect the circuit.
- An open circuit will result in 2nd gear to be stuck on while grounded circuit will result in no 2nd gear and will probably also result in DTC 25- No TCC.

[1] Select Malfunction History from Scan tool TCM menu.