LEMON Manuals: Even more car manuals for everyone
Home >> Mazda >> 2021 >> 3 Base >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Communication Devices >> On-Board Diagnostic - HS/Ms - Can >> DETERMINING SHORT BETWEEN CIRCUITS LOCATION (CAN-BUS No. 1) (US) >> Determination Procedure

Determination Procedure

CAUTION:
  • When disconnecting the connector, verify that there is no looseness, damage, deformation, corrosion, or poor connection of the connector terminals.
  • When inspecting the connector, touch it with a paper clip or similar thin pin without directly inserting a tester probe into the terminal.
  • Disconnect the negative battery terminal before performing any work that requires handling of connectors.
DETERMINING SHORT BETWEEN CIRCUITS LOCATION (CAN-BUS No. 1) (US) DIAGNOSTIC PROCEDURE

Step Inspection Action
1 INSPECT BODY CONTROL MODULE (BCM) FOR SHORT BETWEEN CIRCUITS
Yes Go to the next step.
No Replace the body control module (BCM) because there is a short between circuits in the body control module (BCM).
(See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION .)
2 INSPECT CAN LINE BETWEEN CONNECTOR C-40 AND BODY CONTROL MODULE (BCM) FOR SHORT BETWEEN CIRCUITS
Yes Repair or replace the wiring harness between the body control module (BCM) and connector C-40 because the wiring harness is shorted between circuits.
No Go to the next step.
3 INSPECT CAN LINE BETWEEN EPS CONTROL MODULE AND CONNECTOR C-40 FOR SHORT BETWEEN CIRCUITS
Yes Go to the next step.
No Go to Step 5.
4 INSPECT EPS CONTROL MODULE FOR SHORT BETWEEN CIRCUITS
  • Disconnect the EPS control module connector.
  • Inspect for continuity between EPS control module terminals 2C and 2A (wiring harness side).
  • Is there continuity?
Yes Repair or replace the wiring harness between the EPS control module and connector C-40 because the wiring harness is shorted between circuits.
No Replace the EPS control module because there is a short between circuits in the EPS control module.
(See STEERING WHEEL AND COLUMN REMOVAL/INSTALLATION (US) .)
5 INSPECT CAN LINE BETWEEN AFS CONTROL MODULE/AUTO LEVELING CONTROL MODULE AND CONNECTOR C-40 FOR SHORT BETWEEN CIRCUITS
  • Inspect for continuity between AFS control module/auto leveling control module terminals I and J.
  • Is there continuity?
Yes Go to the next step.
No Go to Step 7.
6 INSPECT AFS CONTROL MODULE/AUTO LEVELING CONTROL MODULE FOR SHORT BETWEEN CIRCUITS
  • Disconnect the AFS control module/auto leveling control module connector.
  • Inspect for continuity between AFS control module/auto leveling control module terminals I and J (wiring harness side).
  • Is there continuity?
Yes Repair or replace the wiring harness between the AFS control module/auto leveling control module and connector C-40 because the wiring harness is shorted between circuits.
No Replace the AFS control module/auto leveling control module because there is a short between circuits in the AFS control module/auto leveling control module.
(See ADAPTIVE FRONT LIGHTING SYSTEM (AFS) CONTROL MODULE REMOVAL/INSTALLATION .)
7 INSPECT CAN LINE BETWEEN CONNECTOR C-13 AND CONNECTOR C-40 FOR SHORT BETWEEN CIRCUITS
  • Disconnect the connector C-13.
  • Connect the connector C-40.
  • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .)
  • Switch the ignition ON (engine off).
  • Measure the voltage at body control module (BCM) terminals 3X and 3W.
  • Is the voltage at body control module (BCM) terminals 3X and 3W the same?
Yes Repair or replace the wiring harness between connector C-13 and connector C-40 because the wiring harness is shorted between circuits.
No Go to the next step.
8 INSPECT CAN LINE BETWEEN CONNECTOR C-21 AND CONNECTOR C-13 FOR SHORT BETWEEN CIRCUITS
Yes Repair or replace the wiring harness between connector C-21 and connector C-13 because the wiring harness is shorted between circuits.
No Go to the next step.
9 INSPECT CAN LINE BETWEEN CONNECTOR C-21 AND PCM FOR SHORT BETWEEN CIRCUITS
  • Measure the voltage at PCM terminals 2S and 2T.
  • Is the voltage at PCM terminals 2S and 2T the same?
Yes Go to Step 13.
No Go to the next step.
10 INSPECT CAN LINE BETWEEN CONNECTOR C-21 AND CONNECTORS C-55, C-56 FOR SHORT BETWEEN CIRCUITS
Yes Repair or replace the wiring harness between connector C-21 and connectors C-55, C-56 because the wiring harness is shorted between circuits.
No Go to the next step.
11 INSPECT CAN LINE BETWEEN SAS CONTROL MODULE AND CONNECTORS C-55, C-56 FOR SHORT BETWEEN CIRCUITS
  • Measure the voltage at PCM terminals 2S and 2T.
  • Is the voltage at PCM terminals 2S and 2T the same?
Yes Repair or replace the wiring harness between the connectors C-55, C-56 and connector C-21 because the wiring harness is shorted between circuits.
No Go to the next step.
12 INSPECT SAS CONTROL MODULE FOR SHORT BETWEEN CIRCUITS
  • Switch the ignition off.
  • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .)
  • Disconnect the SAS control module connector.
  • Inspect for continuity between SAS control module terminals 3A and 3D (wiring harness side).
  • Is there continuity?
Yes Repair or replace the wiring harness between the SAS control module and connectors C-55, C-56 because the wiring harness is shorted between circuits.
No Replace the SAS control module because there is a short between circuits in the SAS control module.
(See SAS CONTROL MODULE REMOVAL/INSTALLATION [TWO-STEP DEPLOYMENT CONTROL SYSTEM - US/CANADA SPEC.] .)
13 INSPECT CAN LINE BETWEEN CONNECTOR C-07 AND CONNECTOR C-21 FOR SHORT BETWEEN CIRCUITS
Yes Repair or replace the wiring harness between connector C-07 and connector C-21 because the wiring harness is shorted between circuits.
No
  • Go to the next step. (VIN Y) (with connectors C-37, C-36)
  • Go to Step 16. (VIN Y) (without connectors C-37, C-36)
  • Go to Step 17. (VINs 7, L, M (MTX)) (with connectors C-37, C-36)
  • Go to Step 17. (VINs 7, L, M (MTX)) (without connectors C-37, C-36)
14 INSPECT CAN LINE BETWEEN CONNECTORS C-37, C-36 AND CONNECTOR C-07 FOR SHORT BETWEEN CIRCUITS
Yes Go to Step 17.
No Go to the next step.
15 INSPECT CAN LINE BETWEEN CONNECTOR C-02 AND CONNECTOR C-07/CONNECTORS C-37, C-36 FOR SHORT BETWEEN CIRCUITS
Yes Repair or replace the wiring harness between the connector C-02 and connector C-07/connectors C-37, C-36 because the wiring harness is shorted between circuits.
No Go to the next step.
16 INSPECT TCM FOR SHORT BETWEEN CIRCUITS
Yes Repair or replace the wiring harness between the TCM and connector C-02 because the wiring harness is shorted between circuits.
No Replace the TCM because there is a short between circuits in the TCM. (See CONTROL VALVE BODY REMOVAL/INSTALLATION [GW6AX-EL (US)] .)
(See CONTROL VALVE BODY REMOVAL/INSTALLATION [ET6A-EL (US)] .)
(See CONTROL VALVE BODY REMOVAL/INSTALLATION [EV6A-EL, EV6AX-EL] .)
17 INSPECT CAN LINE BETWEEN DSC HU/CM AND CONNECTORS C-37, C-36 FOR SHORT BETWEEN CIRCUITS
Yes Go to the next step.
No Go to Step 19.
18 INSPECT DSC HU/CM FOR SHORT BETWEEN CIRCUITS
  • Disconnect the DSC HU/CM connector.
  • Inspect for continuity between DSC HU/CM terminals L and J (wiring harness side).
  • Is there continuity?
Yes Repair or replace the wiring harness between the DSC HU/CM and connectors C-37, C-36 because the wiring harness is shorted between circuits.
No Replace the DSC HU/CM because there is a short between circuits in the DSC HU/CM.
(See DSC HU/CM REMOVAL/INSTALLATION [L.H.D. (US)] .)
19 INSPECT PCM FOR SHORT BETWEEN CIRCUITS
  • Disconnect the PCM connector.
  • Inspect for continuity between PCM terminals 2S and 2T (wiring harness side).
  • Is there continuity?
Yes Repair or replace the wiring harness between the PCM and connectors C-37 C-36 because the wiring harness is shorted between circuits.
No Replace the PCM because there is a short between circuits in the PCM.
(See PCM REMOVAL/INSTALLATION [(VIN Y) (US)] .)
20 INSPECT CAN LINE BETWEEN TCM AND CONNECTOR C-02 FOR SHORT BETWEEN CIRCUITS
Yes Go to the next step.
No Go to Step 22.
21 INSPECT TCM FOR SHORT BETWEEN CIRCUITS
  • Disconnect the TCM connector.
  • Inspect for continuity between TCM terminals E and F (wiring harness side).
  • Is there continuity?
Yes Repair or replace the wiring harness between the TCM and connector C-02 because the wiring harness is shorted between circuits.
No Replace the TCM because there is a short between circuits in the TCM.
(See CONTROL VALVE BODY REMOVAL/INSTALLATION [GW6AX-EL (US)] .)
(See CONTROL VALVE BODY REMOVAL/INSTALLATION [ET6A-EL (US)] .)
(See CONTROL VALVE BODY REMOVAL/INSTALLATION [EV6A-EL, EV6AX-EL] .)
22 INSPECT DSC HU/CM FOR SHORT BETWEEN CIRCUITS
  • Disconnect the DSC HU/CM connector.
  • Inspect for continuity between DSC HU/CM terminals L and J (wiring harness side).
  • Is there continuity?
Yes Go to the next step.
No Replace the DSC HU/CM because there is a short between circuits in the DSC HU/CM.
(See DSC HU/CM REMOVAL/INSTALLATION [L.H.D. (US)] .)
23 INSPECT PCM FOR SHORT BETWEEN CIRCUITS
  • Disconnect the PCM connector.
  • Inspect for continuity between PCM terminals 2S and 2T (wiring harness side).
  • Is there continuity?
Yes Repair or replace the wiring harness between the PCM and connector C-07 because the wiring harness is shorted between circuits.
No Replace the PCM because there is a short between circuits in the PCM.
(See PCM REMOVAL/INSTALLATION [(VIN Y) (US)] .)
24 INSPECT CAN LINE BETWEEN CONNECTOR C-07 AND CONNECTORS C-37, C-36 FOR SHORT BETWEEN CIRCUITS
Yes Repair or replace the wiring harness between the connector C-07 and connectors C-37, C-36 because the wiring harness is shorted between circuits.
No Go to the next step.
25 INSPECT CAN LINE BETWEEN DSC HU/CM AND CONNECTORS C-37, C-36 FOR SHORT BETWEEN CIRCUITS
Yes Go to the next step.
No Go to Step 27.
26 INSPECT DSC HU/CM FOR SHORT BETWEEN CIRCUITS
  • Disconnect the DSC HU/CM connector.
  • Inspect for continuity between DSC HU/CM terminals L and J (wiring harness side).
  • Is there continuity?
Yes Repair or replace the wiring harness between the DSC HU/CM and connectors C-37, C-36 because the wiring harness is shorted between circuits.
No Replace the DSC HU/CM because there is a short between circuits in the DSC HU/CM.
(See DSC HU/CM REMOVAL/INSTALLATION [L.H.D. (US)] .)
27 INSPECT CAN LINE BETWEEN CONNECTORS C-37, C-36 AND CONNECTOR C-02 FOR SHORT BETWEEN CIRCUITS
  • Disconnect the connector C-02.
  • Connect the connectors C-37, C-36.
  • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .)
  • Switch the ignition ON (engine off).
  • Measure the voltage at body control module (BCM) terminals 3X and 3W.
  • Is the voltage at body control module (BCM) terminals 3X and 3W the same?
Yes Repair or replace the wiring harness between the connectors C-37, C-36 and connector C-07 because the wiring harness is shorted between circuits.
No
  • Go to Step 30. (VINs 7, L, M (ATX))
  • Go to Step 34. (VINs 7, L, M (MTX))
28 INSPECT CAN LINE BETWEEN DSC HU/CM AND CONNECTOR C-07/CONNECTOR C-02 FOR SHORT BETWEEN CIRCUITS
Yes Go to the next step.
No
  • Go to Step 30. (VINs 7, L, M (ATX))
  • Go to Step 34. (VINs 7, L, M (MTX))
29 INSPECT DSC HU/CM FOR SHORT BETWEEN CIRCUITS
  • Disconnect the DSC HU/CM connector.
  • Inspect for continuity between DSC HU/CM terminals L and J (wiring harness side).
  • Is there continuity?
Yes Repair or replace the wiring harness between the DSC HU/CM and connector C-07/connector C-02 because the wiring harness is shorted between circuits.
No Replace the DSC HU/CM because there is a short between circuits in the DSC HU/CM.
(See DSC HU/CM REMOVAL/INSTALLATION [L.H.D. (US)] .)
30 INSPECT CAN LINE BETWEEN CONNECTOR C-38 AND CONNECTOR C-02 FOR SHORT BETWEEN CIRCUITS
  • Disconnect the connector C-38.
  • Connect the connector C-02.
  • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .)
  • Switch the ignition ON (engine off).
  • Measure the voltage at body control module (BCM) terminals 3X and 3W.
  • Is the voltage at body control module (BCM) terminals 3X and 3W the same?
Yes Repair or replace the wiring harness between connector C-38 and connector C-02 because the wiring harness is shorted between circuits.
No Go to the next step.
31 INSPECT CAN LINE BETWEEN TCM AND CONNECTOR C-38 FOR SHORT BETWEEN CIRCUITS
Yes Go to the next step.
No Go to Step 33.
32 INSPECT TCM FOR SHORT BETWEEN CIRCUITS
  • Disconnect the TCM connector.
  • Inspect for continuity between TCM terminals E and F (wiring harness side).
  • Is there continuity?
Yes Repair or replace the wiring harness between the TCM and connector C-38 because the wiring harness is shorted between circuits.
No Replace the TCM because there is a short between circuits in the TCM. (See CONTROL VALVE BODY REMOVAL/INSTALLATION [GW6AX-EL (US)] .)
(See CONTROL VALVE BODY REMOVAL/INSTALLATION [ET6A-EL (US)] .)
(See CONTROL VALVE BODY REMOVAL/INSTALLATION [EV6A-EL, EV6AX-EL] .)
33 INSPECT CAN LINE BETWEEN CONNECTOR C-38 AND CONNECTOR C-01 FOR SHORT BETWEEN CIRCUITS
  • Disconnect the connector C-01.
  • Connect the connector C-38.
  • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .)
  • Switch the ignition ON (engine off).
  • Measure the voltage at body control module (BCM) terminals 3X and 3W.
  • Is the voltage at body control module (BCM) terminals 3X and 3W the same?
Yes Repair or replace the wiring harness between connector C-01 and connector C-38 because the wiring harness is shorted between circuits.
No Go to Step 35.
34 INSPECT CAN LINE BETWEEN CONNECTOR C-02 AND CONNECTOR C-01 FOR SHORT BETWEEN CIRCUITS
  • Disconnect the connector C-01.
  • Connect the connector C-02.
  • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .)
  • Switch the ignition ON (engine off).
  • Measure the voltage at body control module (BCM) terminals 3X and 3W.
  • Is the voltage at body control module (BCM) terminals 3X and 3W the same?
Yes Repair or replace the wiring harness between connector C-02 and connector C-01 because the wiring harness is shorted between circuits.
No Go to the next step.
35 INSPECT PCM FOR SHORT BETWEEN CIRCUITS
Yes Repair or replace the wiring harness between the PCM and connector C-01 because the wiring harness is shorted between circuits.
No Replace the PCM because there is a short between circuits in the PCM. (See PCM REMOVAL/INSTALLATION [(VIN 7 & VIN L) (US)] .)
(See PCM REMOVAL/INSTALLATION [(VIN M) (US)] .)
(See PCM REMOVAL/INSTALLATION [(VIN Y) (US)] .)