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DTC P1608: Battery Current Sensor Circuit

 
 
 
 
CIRCUIT OPERATION
  • A 5-volt voltage is supplied to the battery current sensor power terminal (terminal No. 1) from the ECM (terminal No. 99). The ground terminal (terminal No. 3) is grounded with ECM (terminal No. 101).
  • A voltage that is proportional to the battery current is sent to the ECM (terminal No. 100) from the battery current sensor output terminal (terminal No. 4).
 
 
TECHNICAL DESCRIPTION
  • The battery current sensor outputs a voltage which corresponds to the battery current.
  • The ECM checks whether this voltage is within a specified range.
 
 
DESCRIPTIONS OF MONITOR METHODS
Battery current sensor output voltage is out of specified range.
 
 
DTC SET CONDITIONS
Check Condition
  • Ignition switch is "ON" position
Judgment Criterion
  • The battery current sensor output voltage is less than 0.2 V for 2 seconds.
or
  • The battery current sensor output voltage is more than 4.8 V for 2 seconds.
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • Prohibits generator output suppression control against current consumers. (Operates as a normal generator.)
 
 
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
  • Battery current sensor failed.
  • Open or shorted battery current sensor circuit, harness damage or connector damage.
  • ECM failed.
 
 
DIAGNOSIS
Required Special Tools:
  • MB991958: Scan Tool (M.U.T.-III Sub Assembly)
    • MB991824: V.C.I.
    • MB991827: USB Cable
    • MB991910: Main Harness A
  • MB992110: Power Plant ECU Check Harness
STEP 1. Check harness connector A-41 at battery current sensor for damage
Is the harness connector in good condition?
Go to Step 2.
Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 13.
 
STEP 2. Check battery current sensor itself
  • Check battery current sensor itself (Refer to GROUP 54A - Battery - Inspection - Battery Current Sensor Check ).
Is the check result normal?
Go to Step 3.
Replace the battery current sensor. Then go to Step 13.
 
STEP 3. Measure the sensor supply voltage at battery current sensor harness side connector A-41.
(1) Disconnect the connector A-41 and measure at the harness side.
(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal No. 1 and ground.
  • Voltage should be between 4.9 and 5.1 volts.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the measured voltage between 4.9 and 5.1 volts?
Go to Step 7.
Go to Step 4.
 
STEP 4. Check harness connector B-27 at ECM for damage.
Is the harness connector in good condition?
Go to Step 5.
Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 13.
 
STEP 5. Check for open circuit and short circuit to ground between battery current sensor connector A-41 (terminal No. 1) and ECM connector B-27 (terminal No. 99).
Is the harness wire in good condition?
Go to Step 6.
Repair it. Then go to Step 13.
 
STEP 6. Using scan tool MB991958, read the diagnostic trouble code (DTC).
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) After the DTC has been deleted, read the DTC again.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is DTC P1608 set?
Replace the ECM (Refer to, Removal and Installation ). Then go to Step 13.
It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions .
 
STEP 7. Check the continuity at battery current sensor harness side connector A-41.
(1) Disconnect the connector A-41 and measure at the harness side.
(2) Check for the continuity between terminal No. 3 and ground.
  • Continuity (2 ohms or less)
Does continuity exist?
Go to Step 10.
Go to Step 8.
 
STEP 8. Check harness connector B-27 at ECM for damage.
Is the harness connector in good condition?
Go to Step 9.
Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 13.
 
STEP 9. Check for open circuit and harness damage between battery current sensor connector A-41 (terminal No. 3) and ECM connector B-27 (terminal No. 101).
Is the harness wire in good condition?
Go to Step 6.
Repair it. Then go to Step 13.
 
STEP 10. Check harness connector B-27 at ECM for damage.
Is the harness connector in good condition?
Go to Step 11.
Repair or replace it. Refer to GROUP 00E, Harness Connector Inspection . Then go to Step 13.
 
STEP 11. Check for harness damage between battery current sensor connector A-41 (terminal No. 1) and ECM connector B-27 (terminal No. 99).
Is the harness wire in good condition?
Go to Step 12.
Repair it. Then go to Step 13.
 
STEP 12. Check for open circuit, short circuit to ground and harness damage between battery current sensor connector A-41 (terminal No. 4) and ECM connector B-27 (terminal No. 100).
Is the harness wire in good condition?
Go to Step 6.
Repair it. Then go to Step 13.
 
STEP 13. Using scan tool MB991958, read the diagnostic trouble code (DTC).
(1) Connect scan tool MB991958 to the data link connector.
(2) Start the engine and run at idle.
(3) After the DTC has been deleted, read the DTC again.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is DTC P1608 set?
Retry the troubleshooting.
The inspection is complete.