What does it mean?
This generic powertrain diagnostic trouble code (DTC) generally applies to many OBD-II vehicles. This may include, but is not limited to, vehicles from Ford, Chevrolet, Toyota, Jeep, etc.
When a P06D1 code is stored, it means the Powertrain Control Module (PCM) has detected an internal processor performance error with the ignition coil control system. Other controllers may also detect an internal PCM performance error (with the ignition coil control system) and cause a P06D1 to be stored.
The internal control module monitoring processors are responsible for various controller self-test tasks and the overall responsibility of the internal control module. The input and output signals of the ignition coil control system are self-tested and are continuously monitored by the PCM and other associated controllers. The Transmission Control Module (TCM), Traction Control System Module (TCSM), and other controllers also interact with the ignition coil control system.
Ignition systems in OBD-II equipped automobiles use a high-intensity spark generated by battery voltage and a tightly wound induction coil. The ignition spark (coil) timing is controlled by the PCM using input signals from the Crankshaft Position (CKP) and Camshaft Position (CMP) sensors. In the coil-on-plug and distributorless ignition system, each cylinder has its own ignition coil. Each coil is attached to the spark plug with a short spark plug wire or a silicone boot.
A constant supply of battery voltage and a ground pulse from the PCM (applied to a tightly wound induction coil) create the high-intensity spark (several thousand volts) necessary to fire the spark plug of each cylinder.
Other ignition systems use coil packs which operate similarly, except that multiple spark plugs are fired from a single coil pack (with multiple towers). In this type of system, multiple cylinders are fired in a sequential order. This type of system typically uses much longer high-tension spark plug wires to transfer the high-intensity spark from the coil pack towers to each spark plug at the appropriate time.
With the ignition switched on, the coils/coil packs are supplied with constant battery voltage. The ignition coil releases a high-intensity spark when it receives a ground pulse from the PCM.
Whenever the ignition is switched on and the PCM is powered up, self-tests for the ignition coil control system are initiated. In addition to performing internal controller self-tests, the Controller Area Network (CAN) also compares the signals from each individual module to ensure each controller is functioning correctly. These tests are performed simultaneously.
If the PCM detects an internal anomaly in the ignition coil control system processor, a P06D1 code will be stored and a Malfunction Indicator Lamp (MIL) may be illuminated.
If the PCM detects a problem between any of the onboard controllers, which would indicate an internal ignition coil control system error, a P06D1 code will be stored and a Malfunction Indicator Lamp (MIL) may be illuminated. Multiple failure cycles may be required for MIL illumination, depending on the perceived severity of the malfunction.
How severe is this DTC?
Internal control module processor codes should be classified as severe. A stored P06D1 code could lead to various driveability issues.
What are some of the symptoms of the code?
Symptoms of a P06D1 trouble code may include:
Driveability problems, including one or more misfires
Decreased engine performance
Poor fuel efficiency
What are some of the common causes of the code?
Causes
of this code may include:
Faulty PCM or PCM programming error
Open or shorted primary/secondary ignition circuits
Faulty ignition coils or coil packs
Faulty crankshaft/camshaft position sensor or circuits
Open or shorted circuit or connectors in the CAN harness
Insufficient control module ground
What are the P06D1 troubleshooting steps?
Even for the most experienced and well-equipped professional technician, diagnosing a P06D1 code can prove very difficult. There is also the issue of reprogramming. Without the necessary reprogramming equipment, it will be impossible to replace a faulty controller and perform a successful repair.
If ECM/PCM power codes are present, they will obviously need to be corrected before attempting to diagnose a P06D1.
There are several preliminary tests that can be performed before declaring a controller faulty. A diagnostic scanner, a digital volt/ohmmeter (DVOM), and a reliable vehicle information source will be required.
Connect the scanner to the vehicle’s diagnostic port and retrieve all stored codes and freeze frame data. You will want to note this information, just in case the code proves to be intermittent. After recording all relevant information, clear the codes and test drive the vehicle until the code resets or the PCM enters readiness mode. If the PCM enters readiness mode, the code is intermittent and will be more difficult to diagnose. The condition which caused the P06D1 to be stored may even need to worsen before a diagnosis can be made. If the code resets, continue with this short list of preliminary tests.
When trying to diagnose a P06D1, information can be your best tool. Search your vehicle information source for Technical Service Bulletins (TSBs) that match the stored code, the vehicle (year, make, model, and engine), and the symptoms presented. If you find the right TSB, it may provide diagnostic information that will help you significantly.
Use your vehicle information source to obtain connector face views, connector pinout diagrams, component locators, wiring schematics, and diagnostic flowcharts related to the code and vehicle in question.
Use the DVOM to test the controller power fuses and relays. Test and replace blown fuses as needed. Fuses should be tested with the circuit loaded.
If all fuses and relays appear to be working as expected, a visual inspection of the wiring and harnesses related to the controller is in order. You will also want to check the chassis and engine ground junctions. Use your vehicle information source to obtain ground locations for related circuits. Use the DVOM to test ground integrity.
Visually inspect the system controllers for signs of water, heat, or collision damage. Any damaged controller, especially by water, should be considered faulty.
If the controller power and ground circuits are intact, suspect a faulty controller or a controller programming error. Replacing the controller will require reprogramming. In some cases, you can purchase pre-programmed controllers through aftermarket sources. Other vehicles/controllers will require onboard reprogramming that can only be performed by a dealership or other qualified source.
Unlike most other codes, P06D1 is likely caused by a faulty controller or a controller programming error
Test system ground integrity by connecting the DVOM negative test lead to ground and the positive test lead to battery voltage