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DTC C101B:1C [EVP CONTROL UNIT]

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2016 – MX-5 – Brakes

DTC C101B:1C [EVP CONTROL UNIT]

DTC

C101B:1C

Vacuum sensor 1 power supply: low voltage/high voltage

DETECTION CONDITION

  • Power supply voltage for vacuum sensor 1 deviates from 4.5 V to 5.5 V for a continuous 0.55 s.

FAIL-SAFE FUNCTION

POSSIBLE CAUSE

  • Vacuum sensor 1 connector or terminals malfunction

  • EVP control unit connector or terminals malfunction

  • Vacuum sensor 1 malfunction

  • Short to ground circuit in wiring harness between vacuum sensor 1 terminal A and EVP control unit terminal AA

  • Short to power supply in wiring harness between vacuum sensor 1 terminal A and EVP control unit terminal AA

  • EVP control unit malfunction

Diagnostic Procedure

Step

Inspection

Action

1

RECORD SNAPSHOT DATA AND DIAGNOSTIC MONITORING TEST RESULTS TO UTILIZE WITH REPEATABILITY VERIFICATION

NOTE:

  • Recording can be facilitated using the screen capture function of the PC.

  • Record the snapshot data and DIAGNOSTIC MONITORING TEST RESULTS (fuel system related) on the repair order.

Go to the next step.

2

DETERMINE WHETHER MALFUNCTION IS PAST OR PRESENT

  • Switch the ignition ON (engine off).

  • Access the VS1_V PID using the M-MDS.

  • Is the VS1_V PID 4.5 V—5.5 V?

Yes

Go to the next step.

No

Go to Step 6.

3

VERIFY DTC REPEATABILITY

  • Switch the ignition ON (engine off).

  • Access the VS1_V PID using the M-MDS.

  • Does the value in PID VS1_V change when the wiring harnesses for vacuum sensor 1 is shaken?

Yes

Go to Step 6.

No

Go to the next step.

4

DRIVE VEHICLE THEN VERIFY DTC REPEATABILITY BASED ON SERVICE QUESTIONING RESULTS AND SNAP SHOT DATA

  • Switch the ignition ON (engine off).

  • Access the VS1_V PID using the M-MDS.

  • Drive the vehicle based on the service questions content and snap shot data driving conditions.

  • Is the VS1_V PID 4.5 V—5.5 V while the vehicle is driven?

Yes

Go to the next step.

No

Go to Step 6.

5

VERIFY DTC REPEATABILITY AND DETERMINE IF MALFUNCTION CAUSE IS EVP CONTROL UNIT

Yes

Replace the EVP control unit, then go to Step 12.

(See EVP CONTROL UNIT REMOVAL/INSTALLATION.)

No

DTC troubleshooting completed.

Explain to the customer that there are no malfunctions with the vehicle based on the contents of the servicing.

6

INSPECT VACUUM SENSOR 1 CONNECTOR CONDITION

  • Switch the ignition OFF.

  • Disconnect the negative battery cable.

    (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION.)

  • Disconnect the vacuum sensor 1 connector.

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

  • Is the connector normal?

Yes

Go to the next step.

No

Repair or replace the connector and/or terminals, then go to Step 11.

7

DETERMINE IF MALFUNCTION CAUSE IS VACUUM SENSOR 1 POWER SUPPLY CIRCUIT SHORT TO GROUND OR POWER SUPPLY

  • Verify that the vacuum sensor 1 connector is disconnected.

  • Connect the negative battery cable.

    (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION.)

  • Switch the ignition ON (engine off).

  • Measure the voltage at the vacuum sensor 1 terminal A (wiring harness-side)—body ground.

  • Is the voltage 4.5 V—5.5 V?

Yes

Replace the power brake unit, then go to Step 11.(Vacuum sensor 1 malfunction)

(See POWER BRAKE UNIT REMOVAL/INSTALLATION.)

No

Go to the next step.

8

INSPECT EVP CONTROL UNIT CONNECTOR CONDITION

  • Switch the ignition OFF.

  • Disconnect the negative battery cable.

    (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION.)

  • Disconnect the EVP control unit connector.

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

  • Is the connector normal?

Yes

    Inspection result from Step 7 is less than 4.5 V:

  • Go to the next step.

    Inspection result from Step 7 exceeds 5.5 V:

  • Go to Step 10.

No

Repair or replace the connector and/or terminals, then go to Step 11.

9

INSPECT VACUUM SENSOR 1 POWER SUPPLY CIRCUIT FOR SHORT TO GROUND

  • Verify that the vacuum sensor 1 and EVP control unit connectors are disconnected.

  • Inspect for continuity between vacuum sensor 1 terminal A (wiring harness-side) and body ground.

  • Is there continuity?

Yes

Refer to the wiring diagram and verify whether or not there is a common connector between vacuum sensor 1 terminal A and EVP control unit terminal AA.

    If there is a common connector:

  • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground circuit.

  • Repair or replace the malfunctioning part.

    If there is no common connector:

  • Repair or replace the wiring harness which has a short to ground circuit.

Go to Step 11.

No

Replace the EVP control unit, then go to Step 12. (short to ground in the EVP control unit internal circuit)

(See EVP CONTROL UNIT REMOVAL/INSTALLATION.)

10

INSPECT VACUUM SENSOR 1 POWER SUPPLY CIRCUIT FOR SHORT TO POWER SUPPLY

  • Verify that the vacuum sensor 1 connector is disconnected.

  • Connect the negative battery cable.

    (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION.)

  • Switch the ignition ON (engine off).

  • Measure the voltage at the vacuum sensor 1 terminal A (wiring harness-side)—body ground.

  • Is the voltage above 5.5 V?

Yes

Refer to the wiring diagram and verify whether or not there is a common connector between vacuum sensor 1 terminal A and EVP control unit terminal AA.

    If there is a common connector:

  • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.

  • Repair or replace the malfunctioning part.

    If there is no common connector:

  • Repair or replace the wiring harness which has a short to power supply.

Go to the next step.

No

Replace the EVP control unit, then go to Step 12. (short to ground in the EVP control unit internal circuit)

(See EVP CONTROL UNIT REMOVAL/INSTALLATION.)

11

VERIFY DTC TROUBLESHOOTING COMPLETED

Yes

Repeat the inspection from Step1.

If the malfunction recurs, replace the EVP control unit, then go to the next step.

(See EVP CONTROL UNIT REMOVAL/INSTALLATION.)

No

Go to the next step.

12

VERIFY NO DTC IS PRESENT

  • Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [EVP CONTROL UNIT].)

No

DTC troubleshooting completed.

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