Error Code P06D1 is defined as Internal Control Module Ignition Coil Control Performance. This is a generic trouble code, meaning it applies to all vehicles equipped with the OBD-II system, especially those made since 1996 up to present. This includes vehicle models from but not limited to, Chevrolet, Ford, Jeep, etc. Specifications on the definition, troubleshooting, and repairs, of course, vary from one make and model, and powertrain configuration.
When Error Code P06D1 is stored, this means the PCM (powertrain control module, also known as ECM or engine control module in other vehicle makes) has detected a performance error in the ignition coil control system. Other controllers may also detect an internal PCM performance error (with the ignition coil control system) and cause this code to show up.
The Internal control module monitoring processors are the ones responsible for the self-test duties of various controllers, as well as overall internal control module accountability. Both the TPS/APP sensor input and output signals are subjected to self-test and constantly being monitored by the PCM and other related controllers. The TCM (transmission control module), TCSM (traction control module), and other controllers are subject to the interaction with the ignition coil control system.
OBD-II equipped vehicles comes with ignition systems that use high-intensity spark generated by the battery voltage and a tightly wound induction coil. Using the input signals from the CKP (crankshaft position) and CMP (camshaft position) sensors, the PCM is able to control the ignition spark (coil) timing. In the coil-over-plug, the distributor-less ignition system, each cylinder has its own ignition coil. And each coil is attached to the spark plug, which comes with a short plug wire or silicon boot.
The PCM continually supplies battery voltage and ground pulse (applied to the tightly wound induction coil), which creates a high-intensity spark (thousands of volts) required to fire the spark plug of each cylinder.
Other ignition systems use coil packs which work in a similar way, except multiple spark plugs are fired from a single coil (with multiple towers). For this kind of system, multiple cylinders are fired in sequential order. This system uses much longer high tension spark plug leads, transferring high-intensity spark from the coil pack towers to each spark plug at the right time.
When the ignition is switched on, the coils or coil pack will be supplied with the battery voltage. The ignition coil will release its high-intensity spark as soon as the PCM sends its ground pulse.
When the ignition is on, and the PCM is energized, the ignition coil control system self-tests will initiate. Aside from running internal controller self-tests, the CAN (controller area network) also compares signals from each individual module, ensuring each controller is running properly. These tests are performed simultaneously.
If the PCM sees any discrepancy in the ignition coil control system processor, then it will register the code. Similarly, if the PCM detects a problem between any of the onboard controllers that indicates an error in the internal ignition control system, then it will stored the Error Code P06D1.
- Various drivability issues, such as engine misfire or diminished performance
- Increase in fuel consumption
- Faulty or programming error in PCM
- Open or shorted primary or secondary ignition circuits
- Defective CKP or CMP sensor circuits
- Defective ignition coil or coil park/s
- Insufficient control module ground
- Open or shorted circuit or connectors in CAN harness
This code is one of the tricky codes to diagnose. To make matters more difficult, it could also be a result of a reprogramming issue. Without the right reprogramming equipment, it will be impossible to replace a defective controller and complete the repair.
When diagnosing this code, it’s important to diagnose and repair other related codes first.
There are many preliminary tests before you can declare any defective controller. You’ll need a diagnostic scanner, DVOM (digital volt-ohmmeter), and a reliable vehicle information source.
Then, connect the scanner to the vehicle’s diagnostic port to retrieve all stored codes, including their freeze frame data. Take note of this information in case the problem is proven to be intermittent. Clear the codes then take the vehicle for a test drive. One of the two things can happen; either the code is restored, or the PCM enters readiness mode.
If the code enters readiness mode, then the problem is intermittent. Meaning, you would have to wait for the problem to worsen before you can accurately diagnose it. If the code is restored, however, then you can continue on your diagnosis.
Search for the TSB (technical service bulletins) that replicates the code, vehicle (year, make, model, and engine), and symptoms for the problem. You can find this information from the vehicle information source.
Then, get the face views, connector pinout charts, wiring diagrams, component locators, and diagnostic flow charts of the code for the vehicle in question.
Test the controller power supply fuses and relays using the DVOM. Replace any blown fuses, fusible links, and relays as necessary. To avoid misdiagnosis, fuses must be tested with the circuit loaded.
If fuses and relays appear to be functioning as intended, then proceed on inspecting the controller related wiring and harness (in that order). Also, make sure you check the chassis and engine ground junctions. Get the ground locations for related circuits using the vehicle information source. Then, test the ground integrity using the DVOM.
Make sure you inspect the system controllers for signs of water damage, heat, or collision damage. Any controllers with signs of damage must be considered defective and must be replaced.
If controller power and ground circuits are intact, then you can suspect a defective or programming error in the controller. This means the controller must be reprogrammed. In many cases, you can purchase reprogrammed controllers from aftermarket sources. Some vehicle/controllers require on-board reprogramming that can only be done in the dealership or another qualified source.
How to Fix
Depending on the diagnosis, common repairs for this code include:
- Repair or replacement of burnt, or damaged wirings or connectors
- Replacement of blown fuses, relays, or fusible links
- Repair of open or shorted circuit or connector in the CAN harness
- Replacement and reprogramming of PCM
This error code is categorized as severe and can result in a variety of drivability concerns.
Unlike many codes, this error code is likely caused by a defective or programming error in the controller.
Connect DVOM’s negative test lead to ground, and the positive test lead to battery voltage to test the ground integrity.