Home

Mazdamanuals.com

DTC C0020:11, C0020:12, C0020:13, C0020:49 OR C0020:71 [DSC HU/CM]

id040262003300

Outline

System malfunction location

Pump motor, pump relay

Detection condition

•  C0020:11

―  The motor relay signal does not correspond to the DSC HU/CM ON signal.

•  C0020:12

―  The motor monitor signal does not correspond to the DSC HU/CM OFF signal.

•  C0020:13

―  A condition is detected in which the motor relay voltage is less than the specification while the DSC HU/CM controls the pump relay at on.

•  C0020:49

―  The DSC HU/CM detects a pump motor drive circuit malfunction.

•  C0020:71

―  The DSC HU/CM detects a voltage decrease occurring in the pump motor after the pump motor operates.

Fail-safe

Refer to “DTC Table” and “Fail-safe Function Malfunction Contents Table”.(See DTC TABLE [DSC HU/CM (E)].)

Possible cause

•  DSC HU/CM connector or terminals malfunction

•  Short to ground or open circuit in DSC HU/CM power supply circuit

•  Open circuit in DSC HU/CM ground circuit

•  DSC HU/CM malfunction

―  Pump motor stuck, open circuit, short circuit to ground, or short circuit to power supply

―  Motor relay stuck, open circuit, short circuit to ground, or short circuit to power supply

System malfunction location	Pump motor, pump relay
Detection condition	• C0020:11 ― The motor relay signal does not correspond to the DSC HU/CM ON signal. • C0020:12 ― The motor monitor signal does not correspond to the DSC HU/CM OFF signal. • C0020:13 ― A condition is detected in which the motor relay voltage is less than the specification while the DSC HU/CM controls the pump relay at on. • C0020:49 ― The DSC HU/CM detects a pump motor drive circuit malfunction. • C0020:71 ― The DSC HU/CM detects a voltage decrease occurring in the pump motor after the pump motor operates.
Fail-safe	Refer to “DTC Table” and “Fail-safe Function Malfunction Contents Table”.(See DTC TABLE [DSC HU/CM (E)].)
Possible cause	• DSC HU/CM connector or terminals malfunction • Short to ground or open circuit in DSC HU/CM power supply circuit • Open circuit in DSC HU/CM ground circuit • DSC HU/CM malfunction ― Pump motor stuck, open circuit, short circuit to ground, or short circuit to power supply ― Motor relay stuck, open circuit, short circuit to ground, or short circuit to power supply

Diagnostic Procedure

Step

Inspection

Results

Action

1

VERIFY PUMP MOTOR OPERATION

•  Verify if the pump motor operates using the simulation item TCS_PUMP_MOTOR.
(See SIMULATION INSPECTION.)

(See SIMULATION TABLE [DSC HU/CM].)

•  Does the pump motor operate?

Yes

Perform the repair completion verification.

No

Go to the next step.

2

INSPECT DSC HU/CM CONNECTOR FOR MALFUNCTION

•  Inspect the applicable connector and terminal.
(See CONNECTOR INSPECTION.)

•  Are the connector and terminal normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

3

INSPECT DSC HU/CM POWER SUPPLY CIRCUIT FOR SHORT TO GROUND AND OPEN CIRCUIT

•  Inspect the power supply circuit for an open circuit and short to ground.
(See CIRCUIT INSPECTION.)

•  Is the circuit normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

4

INSPECT DSC HU/CM POWER SUPPLY CIRCUIT FOR SHORT TO POWER SUPPLY

•  Inspect the applicable circuit for a short to power supply.
(See CIRCUIT INSPECTION.)

•  Is the circuit normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

5

INSPECT DSC HU/CM GROUND CIRCUIT FOR OPEN CIRCUIT

•  Inspect the applicable circuit for open circuit.
(See CIRCUIT INSPECTION.)

•  Is the circuit normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

Repair completion verification 1

VERIFY THAT VEHICLE IS REPAIRED

•  Install/connect the part removed/disconnected during the troubleshooting procedure.

•  Clear the DTC recorded in the memory.
(See CLEARING DTC.)

•  Start the engine and drive the vehicle at 10 km/h {6.2 mph} or more.

•  Perform the DTC inspection for the DSC HU/CM.
(See DTC INSPECTION.)

•  Is the same Pending DTC present?

Yes

Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.

(See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].)

If the CAN communication is normal, perform the diagnosis from Step 1.

•  If the malfunction recurs, replace the DSC HU/CM, then go to the next step.
(See DSC HU/CM REMOVAL/INSTALLATION [L.H.D. (E)].)

(See DSC HU/CM REMOVAL/INSTALLATION [R.H.D.].)

No

Go to the next step.

Repair completion verification 2

VERIFY IF OTHER DTCs DISPLAYED

•  Perform the DTC inspection.
(See DTC INSPECTION.)

•  Are any DTCs displayed?

Yes

Repair the malfunctioning location according to the applicable DTC troubleshooting.

No

DTC troubleshooting completed.

Step	Inspection	Results	Action
1	VERIFY PUMP MOTOR OPERATION • Verify if the pump motor operates using the simulation item TCS_PUMP_MOTOR. (See SIMULATION INSPECTION.) (See SIMULATION TABLE [DSC HU/CM].) • Does the pump motor operate?	Yes	Perform the repair completion verification.
1		No	Go to the next step.
2	INSPECT DSC HU/CM CONNECTOR FOR MALFUNCTION • Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) • Are the connector and terminal normal?	Yes	Go to the next step.
2		No	Repair or replace the malfunctioning location and perform the repair completion verification.
3	INSPECT DSC HU/CM POWER SUPPLY CIRCUIT FOR SHORT TO GROUND AND OPEN CIRCUIT • Inspect the power supply circuit for an open circuit and short to ground. (See CIRCUIT INSPECTION.) • Is the circuit normal?	Yes	Go to the next step.
3		No	Repair or replace the malfunctioning location and perform the repair completion verification.
4	INSPECT DSC HU/CM POWER SUPPLY CIRCUIT FOR SHORT TO POWER SUPPLY • Inspect the applicable circuit for a short to power supply. (See CIRCUIT INSPECTION.) • Is the circuit normal?	Yes	Go to the next step.
4		No	Repair or replace the malfunctioning location and perform the repair completion verification.
5	INSPECT DSC HU/CM GROUND CIRCUIT FOR OPEN CIRCUIT • Inspect the applicable circuit for open circuit. (See CIRCUIT INSPECTION.) • Is the circuit normal?	Yes	Go to the next step.
5		No	Repair or replace the malfunctioning location and perform the repair completion verification.
Repair completion verification 1	VERIFY THAT VEHICLE IS REPAIRED • Install/connect the part removed/disconnected during the troubleshooting procedure. • Clear the DTC recorded in the memory. (See CLEARING DTC.) • Start the engine and drive the vehicle at 10 km/h {6.2 mph} or more. • Perform the DTC inspection for the DSC HU/CM. (See DTC INSPECTION.) • Is the same Pending DTC present?	Yes	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].) If the CAN communication is normal, perform the diagnosis from Step 1. • If the malfunction recurs, replace the DSC HU/CM, then go to the next step. (See DSC HU/CM REMOVAL/INSTALLATION [L.H.D. (E)].) (See DSC HU/CM REMOVAL/INSTALLATION [R.H.D.].)
Repair completion verification 1		No	Go to the next step.
Repair completion verification 2	VERIFY IF OTHER DTCs DISPLAYED • Perform the DTC inspection. (See DTC INSPECTION.) • Are any DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting.
Repair completion verification 2		No	DTC troubleshooting completed.