Diagnostic Aids
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Inspect the TAC module connectors for signs of water intrusion. If water intrusion occurs, multiple DTCs may set without any circuit or component conditions found during diagnostic testing.
- The APP sensor 1 and the throttle position (TP) sensor 1 5-volt reference circuits are internally connected within the TAC module.
- The APP sensor 2 and the TP sensor 2 5-volt reference circuits are internally connected within the TAC module.
- When the TAC module detects a condition within the TAC system, more than one TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Remember this if you review the information stored in Captured Info.
- For an intermittent, refer to Intermittent Conditions .
DTC P1125
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views |
||||
| 1 |
IMPORTANT:
This DTC indicates that two or more accelerator pedal position (APP) sensor DTCs are also set. Diagnose the APP sensor DTCs that are set. Did you perform the Diagnostic System Check - Engine Controls? |
- | Go to Step 2 | Go to Diagnostic System Check - Engine Controls |
| 2 | Record the throttle actuator control (TAC) module calibration with a scan tool. Does the TAC module calibration match the part number of the TAC module? |
- | Go to Step 3 | Go to Step 11 |
| 3 | Observe the DTC Information with a scan tool. Is DTC P2120 or P2125 also set? |
- | Go to Diagnostic Trouble Code (DTC) List | Go to Step 4 |
| 4 |
|
- | Go to Step 5 | Go to Intermittent Conditions |
| 5 |
|
5 ohm | Go to Step 9 | Go to Step 6 |
| 6 | Test the signal circuit of the APP sensor 1 for a short to the signal circuit of the APP sensor 2. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 12 | Go to Step 7 |
| 7 | Test for an intermittent and for a poor connection at the TAC module. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 12 | Go to Step 8 |
| 8 | Test for an intermittent and for a poor connection at the APP sensor. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 12 | Go to Step 10 |
| 9 | Repair the high resistance in the circuit that measured above the specified value. Refer to Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 12 | - |
| 10 | Replace the APP sensor. Refer to Accelerator Pedal Position (APP) Sensor Replacement
. Did you complete the replacement? |
- | Go to Step 12 | - |
| 11 | Replace the TAC module. Refer to Throttle Actuator Control (TAC) Module Replacement
. Did you complete the replacement? |
- | Go to Step 12 | - |
| 12 |
|
- | Go to Step 2 | Go to Step 13 |
| 13 |
IMPORTANT:
Be aware that repairing one individual condition may correct more than one DTC. Observe the Capture Info with a scan tool.Are there any DTCs that have not been diagnosed? |
- | Go to Diagnostic Trouble Code (DTC) List | System OK |