DTC P0051 [AJ] (VIN: JM0 LW10J300 301406-, JMZ LW69J7*# 307683-, JM8 LW28J**# 301514-, JM8 LW28A**# 301514- (Assumed))

BME010200001W05

DTC P0051

HO2S heater (Front, LH) circuit low

DETECTION CONDITION

• The PCM monitors the HO2S heater (Front, LH) control signal at PCM terminal 84. If the PCM turns the HO2S heater (Front, LH) off but HO2S heater (Front, LH) circuit has low voltage, the PCM determines that the HO2S heater (Front, LH) circuit has malfunction.
Note
• The HO2S heater (Front, LH) is controlled by a duty signal.
Diagnostic support note
• This is an intermittent monitor (HO2S heater).
• 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.
• DTC is stored in PCM memory.

POSSIBLE CAUSE

• HO2S (Front, LH) malfunction
• Open circuit between the ignition switch and HO2S (Front, LH) terminal C
• Open circuit between the HO2S (Front, LH) terminal D and PCM terminal 84
• Short to ground circuit between HO2S (Front, LH) terminal D and PCM terminal 84
• PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED
• Have FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS (HO2S heater related) been recorded?
Yes
Go to the next step.
No
Record FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on repair order, then go to the next step.
2
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
• Check for related Service Information availability.
• Is any related Service Information available?
Yes
Perform repair or diagnosis according to available Service Information.
• If vehicle is not repaired, go to next step.
No
Go to next step.
3
INSPECT HO2S (FRONT, LH) CONNECTOR FOR POOR CONNECTION
• Turn the ignition switch off.
• Disconnect HO2S (Front, LH) connector.
• Check for poor connection (damaged, pulled-out pins, corrosion, etc.).
• Are there any malfunctions?
Yes
Repair or replace terminal, then go to Step 9.
No
Go to next step.
4
INSPECT HO2S HEATER (FRONT, LH)
• Inspect HO2S heater (front, LH).
• Is HO2S heater (front, LH) normal?
Yes
Go to next step.
No
Replace the HO2S (Front, LH), then go to Step 9.
5
INSPECT HO2S HEATER (FRONT, LH) POWER CIRCUIT FOR OPEN CIRCUIT
• Turn the ignition switch to ON (Engine OFF).
• Measure voltage between HO2S (Front, LH) terminal C (harness-side) and body ground.
• Is there voltage B+?
Yes
Go to next step.
No
Repair or replace harness for open circuit, then go to Step 9.
6
INSPECT PCM CONNECTOR FOR POOR CONNECTION
• Turn the ignition switch off.
• Disconnect PCM connector.
• Check for poor connection (damaged, pulled-out pins, corrosion, etc.).
• Are there any malfunctions?
Yes
Repair terminal, then go to Step 9.
No
Go to next step.
7
INSPECT HO2S HEATER (FRONT, LH) CONTROL CIRCUIT FOR SHORT TO GROUND
• Check continuity between HO2S (Front, LH) terminal D (harness-side) and body ground.
• Is there any continuity?
Yes
Repair or replace harness for short to ground, then go to Step 9.
No
Go to next step.
8
INSPECT HO2S HEATER (FRONT, LH) CONTROL CIRCUIT FOR OPEN CIRCUIT
• Disconnect PCM connector.
• Check continuity between HO2S (Front, LH) terminal D (harness-side) and PCM terminal 84.
• Is there any continuity?
Yes
Go to next step.
No
Repair or replace harness for open circuit, then go to Step 9.
9
VERIFY TROUBLESHOOTING OF DTC P0051 COMPLETED
• Make sure to reconnect all disconnected connectors.
• Clear DTC from PCM memory using WDS or equivalent.
• Start engine and warm it up completely.
• Is PENDING CODE of same DTC present?
Yes
Replace PCM, then go to next step.
No
Go to next step.
10
VERIFY AFTER REPAIR PROCEDURE
• Perform "After Repair Procedure".
• Is there any DTC present?
Yes
Go to applicable DTC inspection.
No
Troubleshooting completed.