Mazda DTC P2507 Diagnostic

DTC P2507

 

  

PCM B+ voltage low

 
DETECTION CONDITION

• The PCM monitors the voltage of back-up battery positive terminal at PCM terminal 1BA. If the PCM detected battery positive terminal voltage below 2.5 V for 2 s, the PCM determines that the backup voltage circuit has malfunction.
POSSIBLE CAUSE

• Melt down EEC fuse

• Open circuit in wiring between EEC fuse and PCM terminal 1BA

• Short to ground between EEC fuse and PCM terminal 1BA
• Poor connection of PCM connector
• PCM malfunction

Diagnostic procedure

 
 

STEP

 

  

INSPECTION

 

  

ACTION

 

1
 VERIFY FREEZE FRAME DATA HAS BEEN RECORDED

• Has FREEZE FRAME PID DATA been recorded?

Yes

Go to the next step.

No

Record FREEZE FRAME PID DATA on repair order, then go to the next step.

2
 VERIFY RELATED REPAIR INFORMATION AVAILABILITY

• Check for related service repair information availability.

• Is any related repair information available?

Yes

Perform repair or diagnosis according to available repair information.

• If vehicle is not repaired, go to the next step.

No

Go to the next step.

3
 INSPECT EEC FUSE

• Turn the ignition switch to off.

• Inspect EEC fuse for failure and proper.

• Is it normal?

Yes

Go to step 6.

No

• If EEC fuse has been melt down, then go to the next step.

• If EEC fuse is not installed correctly, install it correctly then go to Step 7.

4
 INSPECT MONITOR CIRCUIT FOR SHORT TO GROUND

• Disconnect battery cables.

• Inspect continuity between EEC fuse terminal and body ground.

• Is there continuity?

Yes

Repair or replace wiring harness for short to ground and install new fuse, then go to Step 7.

No

Go to step 7.

5
 INSPECT PCM CONNECTOR FOR POOR CONNECTION

• Disconnect PCM connector.

• Inspect for poor connection (such as damaged, pulled-out terminals, corrosion).

• Is there any malfunction?

Yes

Repair terminals, then go to Step 7.

No

Go to the next step.

6
 INSPECT MONITOR CIRCUIT FOR OPEN CIRCUIT

• Disconnect battery cables.

• Inspect continuity between EEC fuse terminal and PCM terminal 1BA (wiring harness-side).

• Is there continuity?

Yes

Go to the next step.

No

Repair or replace wiring harness for open circuit, then go to the next step.

7
 VERIFY TROUBLESHOOTING OF DTC P2507 COMPLETED

• Make sure to reconnect all disconnected connectors.

• Turn the ignition switch to the ON position (Engine off).

• Clear DTC from PCM memory using WDS or equivalent.

• Start engine and warm it up completely.

• Is same DTC present?

Yes

Replace PCM, then go to the next step.

No

Go to the next step.

8
 VERIFY AFTER REPAIR PROCEDURE

• Perform “After Repair Procedure”.

• Are any DTC present?

Yes

Go to the applicable DTC inspection.

No

Troubleshooting completed.