What this code means
P16E8 means the integrated control module may not be receiving the shutter grille signal it expects over the LIN communication line.
What the vehicle may do
- The vehicle may have no obvious driveability complaint.
- The vehicle may behave like there is an active shutter grille communication issue.
- A warning or stored communication fault may be present depending on vehicle conditions.
Possible fault areas
- Possible shutter grille power or ground circuit issue.
- Possible LIN circuit issue involving the battery sensor LIN line.
- Possible shorted component connected to the LIN circuit.
- Possible shutter grille issue.
- Possible ICM issue after the other checks are normal.
Diagnostic path
Code overview and starting point
On this Accord Hybrid, P16E8 is a shutter grille LIN communication fault. In plain terms, the integrated control module may not be getting the shutter grille signal it expects over the LIN line. The vehicle may not have an obvious driveability complaint, but it can act like an active shutter communication problem. The broad fault areas are possible power, ground, or LIN circuit issues, a possible problem in another component tied into that LIN circuit, the shutter grille itself, or the ICM. Before going deep, start with the basic system checks and use a structured diagnostic approach. If other codes are present, check what they mean first, because one related communication code changes the path you take for P16E8.
Set up the diagnostic path
First, decide whether the related shutter grille communication code is present. If it is present, use the fuller path: check the external power, LIN, and ground circuits, isolate the components connected to the LIN circuit, check the LIN circuit for a short to ground, then move into shutter grille checks and the ICM decision. If that related code is not present, the path is shorter: external circuit checks first, then shutter grille checks, then the ICM decision. To reproduce the fault check, turn the vehicle to ON mode and wait 10 seconds before judging the result.
Check the external circuits first
Now inspect the shutter grille power feed, the battery sensor LIN circuit, and ground. With the vehicle off, disconnect the shutter grille 4P connector, the 12 volt battery sensor 3P connector, and ICM connector P, the 36P connector. Then run the circuit checks with the shutter grille connector and ICM connector P disconnected. Normal power feed on the shutter grille power circuit is 12 V battery voltage. Normal continuity on the LIN open-wire check is less than 1 Ω, and normal continuity on the ground open-wire check is less than 1 Ω. For the LIN short-to-ground check, use the open and short inspection method for that circuit; normal is more than 1 MΩ. If any of these external circuit checks are abnormal, you have a circuit problem. And if the power supply check is the one that failed, continue with the additional power supply inspection to locate where that failure is.
Isolate components on the LIN circuit when that path applies
If the external circuit checks normal and your path calls for isolating the components on the battery sensor LIN circuit, keep the shutter grille connector, the 12 volt battery sensor connector, and ICM connector P disconnected to start. Then reconnect the 12 volt battery sensor connector and ICM connector P one at a time while performing the inspection. The normal result for the internal circuit of a part connected to the LIN circuit is not shorted. If the check becomes abnormal when a component is reconnected, the problem is with the part that shorted when it was reconnected. This type of isolation check can be done early, but if it fails, you still need to continue the individual checks so you know exactly which item failed.
Check the shutter grille side
Once the external circuit is normal, move to the shutter grille inspection. There is not a direct component-only test here, so the diagnosis is done through the related circuits and components. Run the same ON-mode fault check again and judge whether the related shutter grille communication code is gone. If that check is normal, the path points to a problem with the shutter grille. If the check is still abnormal, the path points toward other related components. Next, with the external circuit still confirmed normal, disconnect the 12 volt battery sensor 3P connector and ICM connector P. Perform the shutter grille internal circuit inspection with the 12 volt battery sensor connector disconnected. The normal result is not shorted. If that inspection is abnormal, the path points to a problem with the shutter grille.
Final decision and verification
Keep verification separate from testing. After the circuit and shutter grille side checks have all shown normal, the remaining decision in this path is the ICM. If the other inspection items are normal, the procedure determines the remaining ICM is the cause. After the fault area is corrected, verify the repair by repeating the ON-mode check and confirming P16E8 stays gone. The takeaway: do not jump straight to the shutter grille on this one. Prove the power, ground, LIN circuit, connected LIN components, shutter grille side, and only then make the ICM call. For more diagnostic training, visit stepdiagnostics.com.
Final check
This diagnosis is about proving the communication circuit and the connected parts in order before calling the shutter grille or ICM.
For more guided automotive diagnostics, visit STEP Diagnostics.
