DTC P0037:00 [MZR 1.5, MZR 1.6]

id0102f0700600

DTC P0037:00

HO2S heater control circuit low input

DETECTION CONDITION

•  If the input voltage to the HO2S heater drive terminal in the PCM is low for 0.5 s or more even though the HO2S is duty-controlled at under 90% by the PCM.

Note

•  HO2S heater is controlled by duty signal.

Diagnostic support note

•  This is an intermittent monitor (A/F sensor heater, 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 (Mode 2)/Snapshot data is available.

•  The DTC is stored in the PCM memory.

POSSIBLE CAUSE

•  HO2S connector or terminals malfunction

•  HO2S heater malfunction

•  Short to ground in wiring harness between the following terminals:

―  HO2S terminal C—PCM terminal 2I

―  HO2S terminal D—PCM terminal 2AB

•  PCM connector or terminals malfunction

•  Open circuit in wiring harness between the following terminals:

―  HO2S terminal C—PCM terminal 2I

―  HO2S terminal D—PCM terminal 2AB

•  PCM malfunction

DTC P0037:00	HO2S heater control circuit low input
DETECTION CONDITION	• If the input voltage to the HO2S heater drive terminal in the PCM is low for 0.5 s or more even though the HO2S is duty-controlled at under 90% by the PCM. Note • HO2S heater is controlled by duty signal. Diagnostic support note • This is an intermittent monitor (A/F sensor heater, 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 (Mode 2)/Snapshot data is available. • The DTC is stored in the PCM memory.
POSSIBLE CAUSE	• HO2S connector or terminals malfunction • HO2S heater malfunction • Short to ground in wiring harness between the following terminals: ― HO2S terminal C—PCM terminal 2I ― HO2S terminal D—PCM terminal 2AB • PCM connector or terminals malfunction • Open circuit in wiring harness between the following terminals: ― HO2S terminal C—PCM terminal 2I ― HO2S terminal D—PCM terminal 2AB • PCM malfunction

Diagnostic procedure

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA (MODE 2)/SNAPSHOT DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED • Have the FREEZE FRAME DATA (Mode 2)/snapshot data and DIAGNOSTIC MONITORING TEST RESULTS (A/F sensor heater, HO2S heater related) been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA (Mode 2)/snapshot data and DIAGNOSTIC MONITORING TEST RESULTS on repair order, then go to the next step.
2	VERIFY RELATED SERVICE INFORMATION AVAILABILITY • Verify related Service Information availability. • Is any related Service Information available?	Yes	Perform repair or diagnosis according to the available Service Information. • If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	INSPECT HO2S CONNECTOR AND TERMINALS • Switch the ignition to off. • Disconnect the HO2S connector. • Inspect for poor connection (such as damaged/pulled-out pins, and corrosion). • Is there any malfunction?	Yes	Repair or replace the connector or terminals, then go to Step 8.
3		No	Go to the next step.
4	INSPECT HO2S HEATER • Inspect the HO2S heater. (See HEATED OXYGEN SENSOR (HO2S) INSPECTION [MZR 1.5, MZR 1.6].) • Is there any malfunction?	Yes	Replace the HO2S, then go to Step 8. (See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [MZR 1.5, MZR 1.6].)
4		No	Go to the next step.
5	INSPECT HO2S HEATER CIRCUIT FOR SHORT TO GROUND • HO2S connector is disconnected. • Inspect for continuity between the following terminals (wiring harness-side) and body ground: ― HO2S terminal C ― HO2S terminal D • Is there continuity?	Yes	If the short to ground circuit could be detected: • Repair or replace the wiring harness for a possible short to ground. If the short to ground circuit could not be detected: • Replace the PCM (short to ground in PCM internal circuit). (See PCM REMOVAL/INSTALLATION [MZR 1.5, MZR 1.6].) Go to Step 8.
5		No	Go to the next step.
6	INSPECT PCM CONNECTOR AND TERMINALS • Disconnect the PCM connector. • Inspect for poor connection (such as damaged/pulled-out pins, and corrosion). • Is there any malfunction?	Yes	Repair or replace the connector or terminals, then go to Step 8.
6		No	Go to the next step.
7	INSPECT HO2S HEATER CIRCUIT FOR OPEN CIRCUIT • HO2S and PCM connectors are disconnected. • Inspect for continuity between the following terminals (wiring harness-side): ― HO2S terminal C—PCM terminal 2I ― HO2S terminal D—PCM terminal 2AB • Is there continuity?	Yes	Go to the next step.
7		No	Repair or replace the wiring harness for a possible open circuit, then go to the next step.
8	VERIFY DTC TROUBLESHOOTING COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE [MZR 1.5, MZR 1.6].) • Perform the KOEO or KOER self test. (See KOEO/KOER SELF TEST [MZR 1.5, MZR 1.6].) • Is the PENDING CODE for this DTC present?	Yes	Repeat the inspection from Step 1. • If the malfunction recurs, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZR 1.5, MZR 1.6].) Go to the next step.
8		No	Go to the next step.
9	VERIFY AFTER REPAIR PROCEDURE • Perform the “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [MZR 1.5, MZR 1.6].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [MZR 1.5, MZR 1.6].)
9		No	DTC troubleshooting completed.