DTC P1A00[1D] Differential Lock Coil Circuit (Current Error) (Differential Lock)

1. Differential lock control system check

Refer to "53.Driveline Control 3A.Troubleshooting(Differential Lock) diagnostic system check - differential lock controls".

2. Current DTC check

1) Connect the scan tool.

2) Lift up the vehicle.

3) Turn OFF the ignition switch for 30 seconds or more.

4) Operate the vehicle with the following conditions met.

4WD models

  • The rear differential lock switch is ON.
  • The 4WD switch is in 4L.
  • The vehicle speed is 8 km/h {5 MPH} or less.

2WD models

  • The rear differential lock switch is ON.
  • The vehicle speed is 30 km/h {19 mph} or less.

5) Observe the DTC information with a scan tool. Is a DTC set?

Yes

=>Go to Prioritized DTC check.

No

Go to Intermittent conditions of rear differential lock control system.

Refer to "204.Driveline, Axle 17D.Symptom intermittent conditions of differential lock control system".

3. Prioritized DTC check

1) Turn OFF the ignition switch for 30 seconds or more.

2) Turn ON the ignition switch.

3) Observe the DTC information with a scan tool. Is DTC P1A00[13] or P1A00[19] set at the same time?

Yes

Go to the applicable DTC diagnosis.

Refer to "53.Driveline Control 3A.Troubleshooting(Differential Lock) DTC P1A00[13] Differential Lock Coil Circuit (Disconnection)".

Refer to "53.Driveline Control 3A.Troubleshooting(Differential Lock) DTC P1A00[19] Differential Lock Coil Circuit (Short Circuit)".

No

=>Go to Differential lock coil inspection.

4. Differential lock coil inspection

1) Turn OFF the ignition switch.

2) Disconnect the differential lock coil harness connector (R39).

3) Measure the resistance of the differential lock coil harness connector terminal (pins 1 and 2 of R39) with a DMM. Is the resistance equal to the specified value?

Value: 2.65 to 2.95 Ω 20°C {68°F}

Refer to "LHD Differential Lock" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Differential Lock" in the ETM (wiring diagram). (Open using the ETM viewer.).

4) Inspect the differential lock coil circuit for a short to the ground circuit. Is the result normal?

5) Are all of the results normal?

Yes

=>Go to Differential lock coil high-side control circuit inspection.

No

Replace the differential lock coil or repair the circuit as necessary.

Refer to "3.Driveline, Axle 3B.Differentials rear final drive (φ220 mm { 8.66 in })(differential lock) removal".

Refer to "3.Driveline, Axle 3B.Differentials rear final drive (φ220 mm { 8.66 in })(differential lock) disassembly".

Refer to "3.Driveline, Axle 3B.Differentials rear final drive (φ220 mm { 8.66 in })(differential lock) inspection".

Refer to "3.Driveline, Axle 3B.Differentials rear final drive (φ220 mm { 8.66 in })(differential lock) reassembly".

Refer to "3.Driveline, Axle 3B.Differentials rear final drive (φ220 mm { 8.66 in })(differential lock) installation".

=>Go to Repair verification.

5. Differential lock coil high-side control circuit inspection

1) Turn OFF the ignition switch.

2) Disconnect the rear differential lock control unit harness connector (C57).

3) Inspect the wire harnesses and connectors for the following. Is the result normal?

Wire harness to be inspected

  • Between the rear differential lock control unit (pin 8 of C57) and the differential lock coil (pin 1 of R39)

Refer to "LHD Differential Lock" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Differential Lock" in the ETM (wiring diagram). (Open using the ETM viewer.).

Inspection items

  • Open circuit
  • High resistance
  • Short to ground or short to other circuits

Yes

=>Go to Differential lock coil low-side control circuit inspection.

No

Repair the circuit as necessary.

=>Go to Repair verification.

6. Differential lock coil low-side control circuit inspection

1) Inspect the wire harnesses and connectors for the following. Is the result normal?

Wire harness to be inspected

  • Between the rear differential lock control unit (pin 7 of C57) and the differential lock coil (pin 2 of R39)

Refer to "LHD Differential Lock" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Differential Lock" in the ETM (wiring diagram). (Open using the ETM viewer.).

Inspection items

  • Open circuit
  • High resistance
  • Short to ground or short to other circuits

Yes

=>Go to Rear differential lock control unit replacement.

No

Repair the circuit as necessary.

=>Go to Repair verification.

7. Rear differential lock control unit replacement

Note

  • Perform programming after replacing the rear differential lock control unit.

Refer to "3.Driveline, Axle 3Z.Driveline, Axle Electrical Control rear differential lock control unit removal".

Refer to "3.Driveline, Axle 3Z.Driveline, Axle Electrical Control rear differential lock control unit installation".

Refer to "3.Driveline, Axle 3Z.Driveline, Axle Electrical Control rear differential lock control unit setting".

Procedure completion

=>Go to Repair verification.

8. Repair verification

1) Clear the DTC with a scan tool.

2) Turn OFF the ignition switch for 30 seconds or more.

3) Operate the vehicle with the following conditions met.

4WD models

  • The rear differential lock switch is ON.
  • The 4WD switch is in 4L.
  • The vehicle speed is 8 km/h {5 MPH} or less.

2WD models

  • The rear differential lock switch is ON.
  • The vehicle speed is 30 km/h {19 mph} or less.

4) Observe the DTC information with a scan tool.