What this code means
The PCM may not be receiving the battery sensor signal over the LIN communication line.
What the vehicle may do
- The vehicle may show a warning light or stored fault for the battery sensor communication circuit.
- Charging-system or idle-stop behavior can sometimes be affected when battery sensor information is missing or unreliable.
- The concern may be intermittent if the fault is related to a loose terminal or connection issue.
Possible fault areas
- Possible loose terminals at the battery sensor on the battery negative terminal.
- Possible power feed, LIN open, or LIN short-to-ground concern.
- Possible issue with another component connected to the LIN battery sensor circuit.
- Possible battery sensor fault after related checks are normal.
- Possible PCM fault only after the other inspection items are normal.
Diagnostic path
Opening context
On this Honda CR-V, P16E3 is a PGM-FI battery sensor LIN communication fault. In plain terms, the PCM may not be getting the battery sensor signal over the LIN line. The vehicle may show charging or idle-stop related behavior, and the fault area can include the battery sensor connection, the LIN circuit, the shared power feed, other components tied to that LIN line, or, after the rest checks good, the PCM. The key here is not to guess at the sensor first. Work the communication path in order.
Start with the basic checks
Before getting deep into the circuit testing, start with the basic system checks and look closely for loose terminals at the battery sensor on the battery negative terminal. Then decide the path based on whether the companion battery-sensor communication code is also present. If that branch point is not clear on the vehicle, pause, recheck the earlier diagnostic path, and do not guess.
Run the confirmation
For the confirmation check, turn the vehicle to ON mode and wait 60 seconds. This gives the PCM time to see whether the battery sensor communication fault is still present under the required conditions.
Check the power feed and LIN wiring
Next, inspect the shared power feed and the LIN battery sensor circuit. Before disconnecting the PCM connector, jump the SCS line with the HDS and wait more than 1 minute. Then disconnect the battery sensor connector, alternator connector, PCM connector A, shutter grille connector if equipped, and DC-DC converter connector A if equipped with auto idle stop. Run the circuit checks for the power feed, the LIN open, and LIN short-to-ground conditions. Normal is 12 V battery voltage on the +B_SUB_AUDIO check, less than 1 Ω on the LIN open-wire check, and more than 1 MΩ on the LIN short-to-ground check. If one of those readings is abnormal, treat it as a circuit problem. If the power feed side is the one that failed, stay on that power supply path and locate the failure before moving on.
Isolate components on the LIN line
Once the external circuit is normal, isolate the parts connected to the LIN battery sensor line. Again, before disconnecting the PCM connector, jump the SCS line with the HDS and wait more than 1 minute. Disconnect the battery sensor, alternator, PCM connector A, shutter grille connector if equipped, and DC-DC converter connector A if equipped. Then reconnect the alternator, PCM, shutter grille, and DC-DC converter connectors one at a time while checking the LIN line. The normal result is not shorted. If the fault appears when one part is reconnected, replace the part that shorted when it was reconnected. This group test can be run early because it covers several related checks, but if it fails, continue the individual inspections so you know exactly which item caused the failure.
Evaluate the battery sensor indirectly
With the external circuit confirmed normal, move to the battery sensor inspection. There is no direct stand-alone test for the sensor itself in this path, so the diagnosis is made by checking the related components and the resulting code behavior. Run the confirmation procedure by turning the vehicle to ON mode and waiting 60 seconds. If the companion battery-sensor communication code is not indicated, the fault points to the battery sensor. If it is indicated, the fault points toward other related components instead.
Check the battery sensor circuit and remaining PCM call
The last circuit check is the battery sensor circuit inspection, again only after the external circuit is normal. Before disconnecting the PCM connector, jump the SCS line with the HDS and wait more than 1 minute. Disconnect the alternator, PCM connector A, shutter grille connector if equipped, and DC-DC converter connector A if equipped with auto idle stop. Run the sensor internal circuit check. Normal is not shorted. If that check is abnormal, the problem is with the battery sensor. If every other inspection item has shown a normal condition, the remaining fault is determined to be the PCM.
Takeaway
The clean way through P16E3 is to prove the basics first, confirm the fault, test the power and LIN wiring, isolate anything sharing that LIN line, and only then make the sensor or PCM call based on the test results. Keep verification separate from the circuit testing, and make sure the code stays gone. For more diagnostic training, visit stepdiagnostics.com.
Final check
P16E3 is best approached as a communication-path diagnosis: prove the terminals, power feed, LIN wiring, shared components, sensor circuit, and then the remaining controller call in order.
For more guided automotive diagnostics, visit STEP Diagnostics.
