• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage |
---|---|---|---|
TR Signal A | P182A, P182E, P1915 | P182E, P1915 | -- |
TR Signal B | P182E, P1915 | P182C, P182E, P1915 | -- |
TR Signal C | P182E, P1915 | P182F, P182E, P1915 | -- |
TR Signal P | P182D, P182E, P1915 | P182E, P1915 | -- |
Gear Selector Position | A | B | C | P | ||||
---|---|---|---|---|---|---|---|---|
Park | LOW | HI | HI | LOW | ||||
Park/Reverse | LOW | HI | HI | HI | ||||
Reverse | LOW | LOW | HI | HI | ||||
Reverse/Neutral | HI | LOW | HI | HI | ||||
Neutral | HI | LOW | HI | LOW | ||||
Neutral/Drive 5 | HI | LOW | LOW | LOW | ||||
Drive 5 | HI | LOW | LOW | HI | ||||
Drive 5/Drive 4 | LOW | LOW | LOW | HI | ||||
Drive 4 | LOW | LOW | LOW | LOW | ||||
Drive 4/Drive 3 | LOW | HI | LOW | LOW | ||||
Drive 3 | LOW | HI | LOW | HI | ||||
Drive 3/Drive 2 | HI | HI | LOW | HI | ||||
Drive 2 | HI | HI | LOW | LOW | ||||
Open | HI | HI | HI | HI | ||||
Invalid | HI | HI | HI | LOW | ||||
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The internal module switch (IMS) is a sliding contact switch attached to the selector detent inside the transmission side cover. The 4 inputs to the transmission control module (TCM) indicate the transmission range selector position. The input voltage level at the TCM is high, B+, when the IMS is open and low when the switch is closed to ground. The 4 input parameters represented are Signals A, B, C and P - Parity.
• | No engine torque signal DTC P2637. |
• | The engine run time is greater than 5 seconds. |
• | The engine torque is greater than 55-450 N·m (41-332 lb ft). |
• | No engine torque signal DTC P2637. |
• | The engine run time is greater than 5 seconds. |
• | The engine torque is greater than 25 N·m (18 lb ft). |
The engine is running for 5 seconds.
• | No OSS DTCs P0722 or P0723. |
• | No engine torque signal DTC P2637. |
• | Vehicle speed is greater than 8 km/h (5 mph). |
• | Engine torque is greater than 20 N·m (15 lb ft). |
• | DTC P182F has not passed during the current ignition cycle. |
• | The gear ratio is within one of the following ranges: |
- | 3.33:1 to 3.50:1 for first gear |
- | 2.16:1 to 2.27:1 for second gear |
- | 1.56:1 to 1.64:1 for third gear |
- | 0.98:1 to 1.03:1 for fourth gear |
- | 0.73:1 to 0.77:1 for fifth gear |
• | No OSS DTC P0722 or P0723. |
• | The transmission output shaft speed is less than 100 RPM. |
• | The switch indicates PARK for 1 second, then; |
• | The switch indicates a transitional state for greater than 4 seconds. |
• | The switch indicates PARK for 1 second, then; |
• | The switch indicates a transitional state for greater than 5 seconds. |
The TCM detects an invalid switch range for 5 seconds.
The TCM detects Signal C is high, while the gear ratio indicates first, second, third, fourth, or fifth gear for 3 seconds.
The manual shift shaft switch assembly indicates a transitional state during the following sequence:
• | The engine speed is 60 RPM or less for 0.25 second or greater. |
• | The engine speed is 81-625 RPM for 0.15 second or greater. |
• | The engine speed is 651 RPM or greater for 1.5 seconds or greater. |
• | The transmission input shaft speed is 200 RPM or greater for 1.5 seconds or greater. |
• | DTCs P182A, P182C, P182D, P182E, P182F and P1915 are Type B DTCs. |
• | The TCM commands maximum line pressure. |
• | The TCM freezes transmission adaptive functions. |
• | The TCM assumes a D5 shift pattern. |
DTCs P182A, P182C, P182D, P182E, P182F and P1915 are Type B DTCs.
Automatic Transmission Controls Schematics
Transmission General Description
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Transmission Control Module Scan Tool Information
• | J 35616 GM-Approved Terminal Test Kit |
• | J 45681 Jumper Harness |
For equivalent regional tools, refer to Special Tools. |
⇒ | If the transmission fluid is low or discolored, refer to Automatic Transmission Fluid and Filter Replacement. |
Note: Additional DTCs may set when disconnecting the automatic transmission inline 20-way connector.
⇒ | If not the specified value, test the appropriate signal circuit for an open. If the circuits test normal, replace the TCM. |
⇒ | If the IMS A/B/C/P parameter does not display HI/HI/HI/HI, repair the short to ground in the TR signal circuit that displayed LOW between the TCM and the automatic transmission 20-way inline connector. |
⇒ | If the voltage is less than battery voltage, test the affected TR signal for an open between the TCM and the automatic transmission 20-way inline connector. |
⇒ | If the resistance is less than 10 ohms, test the affected TR signal for a short to ground between the automatic transmission 20-way inline connector and the IMS switch. |
⇒ | If any of the TR signal circuits do not display LOW when the range selector is placed in D4, test the affected TR signal for an open or high resistance between the automatic transmission 20-way inline connector and the IMS switch. |
⇒ | If any TR signal circuits do not display continuity when the table indicates it should be LOW, test the affected TR signal circuit for an open or high resistance between the automatic transmission inline 20-way connector and the IMS switch. |
⇒ | If any of the TR signal circuits display less than 10 ohms, test the affected TR signal for a short to ground. |
Perform the Diagnostic Repair Verification after completing the repair.
• | Control Module References for TCM replacement, setup, and programming |