What this code means
P0606 may indicate that the PCM is detecting an internal processor or communication concern, or that the camshaft and crankshaft signal relationship is not what the PCM expects.
What the vehicle may do
- The MIL may illuminate.
- The ETC light may flash.
- Throttle input may be limited.
- Vehicle speed may be limited.
Possible fault areas
- Possible PCM-related concern.
- Possible low system voltage influence.
- Possible camshaft or crankshaft signal concern.
- Possible harness, connector, terminal, or connection issue.
Diagnostic path
Opening context
Today we’re working through P0606 on a 2019 to 2025 Ram 1500DT with the 3.6 Pentastar gas engine. In plain terms, this code points to the PCM seeing an internal processor or communication problem, or a problem with the cam and crank signal relationship being outside what it expects. The truck may turn on the MIL, the ETC light may flash, and throttle input or vehicle speed can be limited. Before condemning anything, keep the possible fault areas broad: PCM concerns, low system voltage, cam or crank signal problems, and connector or harness issues can all steer this diagnosis. Start with the basic pre-diagnostic checks, then stay in order.
Confirm the code and reproduce the conditions
First, scan all ECUs. Read and record the DTCs, and save the vehicle scan report and related recorded data so you know what was there before anything gets cleared. Then erase the codes. Turn the ignition off for a minimum of 10.0 seconds, turn it back on, and operate the vehicle under the conditions that set the code. This monitor runs with the engine running, so use the captured conditions to try to make the fault show itself again. After that, read codes again. If P0606 does not return, treat it as an intermittent condition. If it does return, continue with the next check.
Check for codes that change the direction
Next, look back at the recorded codes. If there are active or pending low system voltage codes, cam sensor codes, or crank sensor codes, handle those applicable diagnostic paths first. Those faults can affect the signal relationship or module behavior, so do not skip over them and jump straight to the PCM. If those related codes are not active or pending, move on to the connection inspection.
Inspect the related connections
Now disconnect the PCM harness connectors, any related in-line connectors if equipped, and the related component connectors. Inspect the connector bodies and terminals closely. You’re looking for improper seating, damaged locks, corrosion, water intrusion, seal damage, bent terminals, overheated or discolored terminals from a poor connection, terminals pushed back in the cavity, spread terminals, and poor terminal tension. Repair anything you find. Then reconnect the PCM connectors, in-line connectors if equipped, and related component connectors. Make sure every connector is fully seated and every lock is fully engaged. Clear the codes again, then test drive or operate the vehicle under the same monitored and setting conditions. Read codes again and see if P0606 returns.
Final decision and verification
If P0606 returns after the connector and terminal checks, and the earlier voltage, cam, and crank code checks did not redirect the diagnosis, the supported next step is to replace and program the PCM, then verify the repair. If the code does not return after repairing a wiring or connection issue, verify the repair and confirm the code stays gone. The takeaway is simple: confirm the code, rule out the faults that can mislead the PCM, inspect the related connections carefully, and only then make the final PCM call. For more diagnostic training, visit stepdiagnostics.com.
Final check
Confirm the fault first, check related voltage and cam/crank code context, inspect the connectors and terminals, then verify the repair after the final action.
For more guided automotive diagnostics, visit STEP Diagnostics.
