CAN Communication Circuit Inspection

WARNING: This page is about a different car, the 2006 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.

CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect the battery cable from the negative terminal.
3. Disconnect the harness connector for each unit on the CAN network and check terminals for deformation, disconnection, looseness or damage.
OK or NG

OK: GO TO 2.

NG: Repair terminal or connector as necessary.

CHECK HARNESS FOR SHORT CIRCUIT

With all module and control unit connectors disconnected, check continuity between ECM harness connector terminals.

ECM CONNECTOR TERMINAL RESISTANCE

ECM connector	Terminal		Continuity
F59	94	86	No

OK or NG

OK: GO TO 3.

NG :

Repair harness.
Change harness if shielded lines are used for the harness.

Fig 1: Checking Continuity Between ECM Harness Connector Terminals

Courtesy of NISSAN MOTOR CO., U.S.A.

CHECK HARNESS FOR SHORT CIRCUIT

Check continuity between ECM harness connector terminals and ground.

ECM CONNECTOR TERMINAL CONTINUITY

ECM connector	Terminal	Ground	Continuity
F59	94		No
F59	86		No

OK or NG

OK: GO TO 4.

NG :

Repair harness.
Change harness if shielded lines are used for the harness.

Fig 2: Checking Continuity Between ECM Harness Connector Terminals And Ground

Courtesy of NISSAN MOTOR CO., U.S.A.

CHECK ECM AND COMBINATION METER INTERNAL CIRCUIT

Remove ECM and combination meter from vehicle.

Check resistance between ECM terminals.

TERMINAL RESISTANCE

Terminal		Resistance (Approx.)
94	86	108 - 132 Ω

Check resistance between combination meter terminals.

Without tachometer

TERMINAL RESISTANCE (WITHOUT TACHOMETER)

Terminal		Resistance (Approx.)
34	35	108 - 132 Ω

With tachometer (QG18DE)

TERMINAL RESISTANCE (WITH TACHOMETER QG18DE)

Terminal		Resistance (Approx.)
38	39	108 - 132 Ω

With tachometer (QR25DE)

TERMINAL RESISTANCE (WITH TACHOMETER QR25DE)

Terminal		Resistance (Approx.)
6	5	108 - 132 Ω

OK or NG

OK: GO TO 5.

NG: Replace ECM and/or combination meter.

Fig 3: Checking ECM And Combination Meter Internal Circuit

Courtesy of NISSAN MOTOR CO., U.S.A.

CHECK SYMPTOM
1. Fill in described symptoms on the column "Symptom" in the check sheet.
2. Connect all connectors, and then make sure that the symptom is reproduced.
OK or NG

OK: GO TO 6.

NG: Refer to "EXAMPLE OF FILLING IN CHECK SHEET WHEN INITIAL CONDITIONS ARE NOT REPRODUCED ".
UNIT REPRODUCIBILITY INSPECTION
Perform the following procedure for each unit on the CAN network, and then perform reproducibility test.
1. Turn ignition switch OFF.
2. Disconnect the battery cable from the negative terminal.
3. Disconnect the unit connector.
4. Connect the battery cable to the negative terminal.
5. Make sure that the symptom filled in the "Symptom" of the check sheet is reproduced. (Do not confuse it with the symptom related to removed unit.)
6. Make sure that the same symptom is reproduced.
Inspection results

Reproduced: Install removed unit, and then check the other unit.

Not reproduced: Replace removed unit.