DTC P2257

BHE010202200W01

DTC P2257

AIR pump relay control circuit low

DETECTION CONDITION

• The PCM monitors the AIR pump relay control voltage when the AIR pump is not operating. If the control voltage is less than 5.8 V, the PCM determines that the AIR pump relay control circuit voltage is low.

Diagnostic support note

• This is a continuous monitor (CCM).
• The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
• PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle.
• FREEZE FRAME DATA is available.
• The DTC is stored in the PCM memory.

POSSIBLE CAUSE

• AIR pump relay malfunction
• Connector or terminal malfunction
• Open circuit in wiring harness between main relay terminal C and AIR pump relay terminal E
• Short to GND in wiring harness between main relay terminal C and AIR pump relay terminal E
• Open circuit in wiring harness between AIR pump relay terminal A and PCM terminal 4O
• Short to GND in wiring harness between AIR pump relay terminal A and PCM terminal 4O
• PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1

VERIFY FREEZE FRAME DATA HAS BEEN RECORDED

• Has FREEZE FRAME DATA been recorded?
Yes
Go to the next step.
No
Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2

VERIFY RELATED REPAIR INFORMATION AVAILABILITY

• Verify related service repair information availability.
• Is any related repair information available?
Yes
Perform repair or diagnosis according to the available repair information.
• If the vehicle is not repaired, go to the next step.
No
Go to the next step.
3

INSPECT AIR PUMP RELAY CONNECTOR FOR POOR CONNECTION

• Turn the ignition switch off.
• Disconnect the AIR pump relay connector.
• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
• Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 9.
No
Go to the next step.
4

INSPECT AIR PUMP RELAY POWER CIRCUIT FOR OPEN CIRCUIT OR SHORT TO GND

• Turn the ignition switch to the ON position (Engine off).
• Measure the voltage between AIR pump relay terminal E (wiring harness-side) and body GND.
• Is the voltage B+?
Yes
Go to the next step.
No
Repair or replace the wiring harness for a possible open circuit or short to GND, then go to Step 9.
5

INSPECT AIR PUMP RELAY CONTROL CIRCUIT FOR SHORT TO GND

• Turn the ignition switch off.
• Inspect for continuity between AIR pump relay terminal A (wiring harness-side) and body GND.
• Is there continuity?
Yes
Repair or replace the wiring harness for a possible short to GND, then go to Step 9.
No
Go to the next step.
6

INSPECT AIR PUMP RELAY

• Inspect the AIR pump relay.
• Is there any malfunction?
Yes
Replace the AIR pump relay , then go to Step 9.
No
Go to the next step.
7

INSPECT PCM CONNECTOR FOR POOR CONNECTION

• Turn the ignition switch off.
• Disconnect the PCM connector.
• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
• Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 9.
No
Go to the next step.
8

INSPECT AIR PUMP RELAY CONTROL CIRCUIT FOR OPEN CIRCUIT

• Turn the ignition switch off.
• Inspect for continuity between AIR pump relay terminal A (wiring harness-side) and PCM terminal 4O (wiring harness-side).
• Is there continuity?
Yes
Go to the next step.
No
Repair or replace the wiring harness for a possible open circuit, then go to the next step.
9

VERIFY TROUBLESHOOTING OF DTC P2257 COMPLETED

• Make sure to reconnect all disconnected connectors.
• Clear the DTC from the PCM memory using the WDS or equivalent.
• Start the engine.
• Is the PENDING CODE same as DTC present?
Yes
Replace the PCM, then go to the next step.
No
Go to the next step.
10

VERIFY AFTER REPAIR PROCEDURE

• Perform the "AFTER REPAIR PROCEDURE".
• Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE.)
No
DTC troubleshooting completed.