GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2005 🢒 STS 🢒 DTC 🢒 DTC P1845

Circuit Description

This diagnostic trouble code (DTC) may set if there is an engine torque limitation caused by requested torque higher than the maximum allowable torque.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P1845 Torque Limit Management

Conditions for Running the DTC

The engine speed is more than 40 RPM.

Conditions for Setting the DTC

The engine torque output exceeds a maximum allowable torque for 10 minutes.

Action Taken When the DTC Sets
    • The control module stores the DTC information into memory when the diagnostic runs and fails.
    • The malfunction indicator lamp (MIL) will not illuminate.
    • The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
    • The driver information center, if equipped, may display a message.

Conditions for Clearing the DTC
    • A current DTC Last Test Failed clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
    • Clear the DTC with a scan tool.

Test Description

The number below refers to the step number on the diagnostic table.

  1. A mechanical condition can cause this DTC to set. Inspect accessory drive components for a condition that could cause excessive drag on the engine.

DTC P1845 Torque Limit Management

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Are any other DTCs set?

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

Go to Step 3

3

Inspect for an engine vacuum leak.

Did you find and correct the condition?

Go to Step 6

Go to Step 4

4

Inspect for a parasitic load on the engine. Inspect the following components:

    • Generator
    • A/C compressor
    • Transmission

Did you find and correct the condition?

Go to Step 6

Go to Step 5

5

Replace the engine control module (ECM). Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 6

--

6
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

Go to Step 2

Go to Step 7

7

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

System OK