C1122

DTC C1122: Engine Speed Signal

Wiring Diagram










DTC Detecting Condition and Trouble Area






DTC Troubleshooting

1.
Was "EPS System Check" performed?
YES -
Go to Step 2.
NO -
Go to EPS System Check EPS System Check:Electric Type.

2. DTC check

Check ECM for DTC referring to DTC Check DTC Check.

Is there any DTC(s) detected?
YES -
Go to applicable DTC troubleshooting.
NO -
Go to Step 3.

3. Engine speed signal circuit check

With ignition switch turned OFF, disconnect P/S control module connector.
Check P/S control module connector for proper connection.
If OK, turn ON ignition switch, measure voltage between "E11-12" wire terminal of P/S control module connector and vehicle body ground.

Is voltage 10 - 14 V?
YES -
Go to Step 4.
NO -
Go to Step 5.

4. ECM voltage check

With ignition switch turned OFF, connect P/S control module and ECM connectors.
Check engine speed signal output referring to Pinout Values and Diagnostic Parameters Inspection of ECM and Its Circuits.

Is it in good condition?
YES -
Substitute a known-good P/S control module and recheck.
NO -
Substitute a known good ECM and recheck.

5. Engine speed signal circuit check

Disconnect ECM connector.
Check that engine speed signal circuit is as follows.
- Insulation resistance of wire harness is infinity between "Engine speed signal circuit" terminal and other terminal at P/S control module connector.
- Wiring harness resistance of "Engine speed signal circuit" is less than 1ohms.
- Insulation resistance between "Engine speed signal circuit" and vehicle body ground is infinity
- Circuit voltage between "Engine speed signal circuit" and ground circuit is 0 - 1 V with ignition switch turned ON.

Is it in good condition?
YES -
Substitute a known good ECM and recheck.
NO -
Repair or replace defective circuit.