P161B

DTC P061B or P161B

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Strategy Based Diagnosis Strategy Based Diagnosis
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions

DTC Descriptors
DTC P061B
- Control Module Torque Calculation Performance

DTC P161B
- Control Module Torque Performance

Circuit/System Description

This diagnostic applies to internal microprocessor integrity conditions within the engine control module (ECM) and the throttle actuator control (TAC) system.

Conditions for Running the DTC

P061B or P161B

The ignition is ON, or the engine is operating.

Conditions for Setting the DTC

P061B

The ECM detects an internal control module torque calculation performance condition.

P161B

The ECM detects that the delivered torque does not match the desired torque.

Action Taken When the DTC Sets

DTCs P061B, and P161B are type A DTCs.

Conditions for Clearing the DTC

DTCs P061B, and P161B are type A DTCs.

Reference Information

Description and Operation

Engine Control Module Description Engine Control Module Description

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Circuit/System Verification

1. Ignition ON, observe the scan tool DTC information parameter. DTCs P061B or P0161B should not set.
2. If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.

Circuit/System Testing

Important: In extreme cold weather conditions ice may form in the vacuum source to the MAP sensor and may set a DTC. Inspect the MAP sensor and the vacuum source for ice, moisture, or other restrictions.


1. Ignition ON, observe the MAP sensor data parameter with a scan tool. Start the engine, verify the MAP sensor data parameter changes.

• If the MAP data parameter does not change, refer to DTC P0107 or P0108 P0107 for further diagnosis.

2. Verify there is not an engine vacuum leak.
3. Test for a parasitic load on the following components:

* Generator
* A/C compressor
* Transmission

• If a condition is found, repair as necessary.

4. If all conditions test normal, replace the ECM

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

Control Module References Control Module References for engine control module replacement, setup, and programming