Circuit Description
The transmission internal mode switch (IMS) is a sliding contact switch attached to the selector detent inside the transmission. The IMS is used by the transmission control module (TCM) to detect the angular position of the shift selector shaft. There are 5 internal switches in the IMS, A, B, C, P, and NS. The TCM uses 4 of these switch inputs to determine the proper gear range that is selected. The fifth switch, NS, located in the IMS, is used as confirmation that the transmission is in NEUTRAL before the engine starter is engaged.
DTC P0706 is a type A DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0706 Transmission Range Sensor Circuit - PRNDL Input
Conditions for Running the DTC
| • | The components are powered and the ignition voltage is greater than 9.0 volts and less than 18 volts. |
| • | Engine speed is less than 350 RPM. |
Conditions for Setting the DTC
DTC P0706 sets when the TCM detects an invalid IMS range input at engine start-up. NEUTRAL or PARK is not indicated.
Action Taken When the DTC Sets
| • | The TCM illuminates the malfunction indicator lamp (MIL). |
| • | The transmission fails to hydraulic default. |
| • | DTC P0708 is stored in TCM history. |
| • | The TCM inhibits main modulation. |
| • | The TCM freezes shift adapts. |
| • | The TCM inhibits torque converter clutch (TCC) engagement. |
Conditions for Clearing the MIL/DTC
A scan tool can clear the code from TCM history. The TCM automatically clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without failure.
Diagnostic Aids
| • | Inspect the wiring for poor electrical connections at the TCM. Inspect for the following conditions: |
| - | A bent terminal |
| - | A backed-out terminal |
| - | A damaged terminal |
| - | Poor terminal tension |
| - | A chafed wire |
| - | A broken wire inside the insulation |
| • | When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change. |
| • | You may have to drive the vehicle in order to experience a condition. |
| • | Due to this failure and associated response, DTC P0722 may also set. |
| • | When monitoring "TR SW" while moving the selector through ranges, A/B/C/P states may indicate transitional states. Transitional states are the area between ranges. |
| • | TR SW A/B/C/P may indicate invalid states when selecting ranges. Invalid states confirm a concern is present. |
Step | Action | Value | Yes | No |
|---|---|---|---|---|
Schematic Reference: Automatic Transmission Controls Schematics | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 | Inspect the shift linkage for proper adjustment. Refer to Range Selector Lever Cable Adjustment . Is the shift linkage properly adjusted? | -- | Go to Step 3 | -- |
3 |
Important: Before clearing the DTC, use the scan tool in order to record the Freeze Frame and Failure Records for reference. The Clear Info function will erase the data. Does each selected transmission range match the scan tool IMS display? | -- | Go to Diagnostic Aids | Go to Step 4 |
4 |
Does each IMS signal indicate OFF when grounded and ON when open? | A = terminal 73 B = terminal 53 C = terminal 14 P = terminal 34 | Go to Step 5 | Go to Step 10 |
5 |
Does each IMS signal indicate OFF when grounded and ON when open? | -- | Go to Step 6 | Go to Step 7 |
6 |
Does each IMS signal indicate OFF when grounded and ON when open? | -- | Go to Step 9 | Go to Step 8 |
7 | Test the IMS circuit between the TCM and AT inline 20-way connector for an open or short to ground condition. Refer to Circuit Testing . Did you find and correct the condition? | -- | Go to Step 11 | -- |
8 | Replace the internal wiring harness. Refer to Wiring Harness Replacement . Did you complete the replacement? | -- | Go to Step 11 | -- |
9 | Replace the internal mode switch. Refer to Transmission Internal Mode Switch Replacement . Did you complete the replacement? | -- | Go to Step 11 | -- |
10 |
Important: In most cases, the TCM is not at fault. Investigate thoroughly before replacing the TCM. Replace the TCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 11 | -- |
11 | Perform the following procedures in order to verify the repair:
Has the test run and passed? | -- | Go to Step 12 | Go to Step 2 |
12 | With the scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK | |
