P1546

DTC P1516 Air Conditioning (A/C) Clutch Relay Control Circuit

Engine Controls Schematics: Heater A/C Control and A/C Compressor Clutch Coil:

Circuit Description

The powertrain control module (PCM) uses the output driver modules (ODMs) in order to turn on many of the current-driven devices that are needed to control various engine and transaxle functions. Each ODM is capable of controlling up to 7 separate outputs by applying ground to the device which the PCM is commanding ON. Unlike the quad driver modules (QDMs) used in prior model years, ODMs are capable of individually diagnosing each output circuit. If an improper voltage level is detected on the output circuit that controls the A/C compressor control relay, DTC P1546 will set.

Conditions for Setting the DTC

- The ignition is ON.
- An improper voltage level has been detected on the output circuit that controls the A/C compressor control relay.
- The above conditions are present for at least 30 seconds.

Action Taken When the DTC Sets

The PCM stores conditions which were present when the DTC set as Failure Records only. This information will not be stored as Freeze Frame Records.

Conditions for Clearing the MIL/DTC

- The DTC becomes history when the conditions for setting the DTC are no longer present.
- The history DTC clears after 40 malfunction free warm-up cycles.
- The PCM receives a clear code command from the scan tool.

Diagnostic Aids

Inspect for the following conditions:

Many situations may lead to an intermittent condition. Perform each inspection or test as directed.

Important: Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

- Loose terminal connection
- Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
- Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
- Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.
- Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.

If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.

Test Description

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

The numbers below refer to the step numbers on the diagnostic table.

1. The Powertrain On Board (OBD) System Check prompts you to complete some basic tests and to store the freeze frame and failure records data on the scan tool.
2. Listen for a click when the relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
3. This step tests for voltage at the coil feed side of the relay.
4. This step verifies that the PCM is providing ground to the relay.
5. This step tests if ground is constantly being applied to the relay.
12. The PCM utilizes an electrically erasable programmable read-only memory (EEPROM). When you replace the PCM, you must program the new PCM.