DTC C1278, C1956

id060200800700

**With P/S Angle Sensor [Applied VIN (Assumed): JM0 BK10100 100001-150353, JM6 BK10100 100001-150353, JM7 BK6# 100001-150353]**


DTC	C1278, C1956		P/S angle sensor
DETECTION CONDITION		• C1278 - The EHPAS control module detects that the monitor voltage from the P/S angle sensor is more than 4.25 V or less than 0.5 V. - The EHPAS control module detects that the two monitor voltages modulate at the same phase a specified amount of phases or more. - The EHPAS control module detects that the EHPAS sensor signal dose not change. • C1956 - The EHPAS control module detects that the power supply voltage of the P/S angle sensor is more than 5.5 V. - The EHPAS control module detects that the power supply voltage of the P/S angle sensor is less than 4.5 V.
POSSIBLE CAUSE		• Short to power supply, open circuit, or short to ground in wiring harness between EHPAS control module terminal 3B and P/S angle sensor D • Short to power supply, open circuit, or short to ground in wiring harness between EHPAS control module terminal 3D and P/S angle sensor terminal B • Open circuit or short to ground in wiring harness between EHPAS control module terminal 3C and P/S angle sensor terminal C • Open circuit in wiring harness between EHPAS control module terminal 3A and P/S angle sensor terminal A • Short circuit in wiring harness between P/S angle sensor terminal B and D • P/S angle sensor ring has fallen off. • Power supply voltage of P/S angle sensor is more than the specified value.

Diagnostic procedure


STEP	INSPECTION		ACTION
1	INSPECT POWER SUPPLY VOLTAGE OF P/S ANGLE SENSOR • Turn the ignition switch to the ON position (Engine off). • Measure the voltage between P/S angle sensor terminal C and ground. • Is the voltage 4.5-5.5 V?	Yes	Go to the next step.
1		No	Repair or replace the wiring harness between EHPAS control module terminal 3C and P/S angle sensor terminal C, then go to the step 7.
2	INSPECT GROUND CIRCUIT OF P/S ANGLE SENSOR FOR OPEN CIRCUIT • Turn the ignition switch off. • Disconnect the EHPAS control module and P/S angle sensor connectors. • Inspect for continuity between EHPAS control module terminal 3A and P/S angle sensor terminal A. • Is there continuity?	Yes	Go to the next step.
2		No	Repair or replace the wiring harness between EHPAS control module terminal 3A and P/S angle sensor terminal A, then go to the step 7.
3	INSPECT P/S ANGLE SENSOR SIGNAL CIRCUIT FOR SHORT TO POWER • Turn ignition key to ON (engine OFF). • Measure the voltage between the EHPAS control module and body ground at the following: - Sensor 1: EHPAS control module terminal 3B and body ground - Sensor 2: EHPAS control module terminal 3D and body ground • Is voltage B+?	Yes	Repair or replace the related wiring harnesses between the EHPAS control module and P/S angle sensor, then go to the step 7.
3		No	Go to next step.
4	INSPECT P/S ANGLE SENSOR SIGNAL CIRCUIT FOR SHORT TO GROUND • Turn the ignition switch off. • Inspect continuity between the EHPAS control module and body ground at the following: - Sensor 1: EHPAS control module terminal 3B and body ground - Sensor 2: EHPAS control module terminal 3D and body ground • Is there continuity?	Yes	Repair or replace the related wiring harnesses between the EHPAS control module and P/S angle sensor, then go to the step 7.
4		No	Go to the next step.
5	INSPECT SENSORS 1 AND 2 OF THE P/S ANGLE SENSOR FOR CONTINUITY • Turn the ignition switch off. • Disconnect the EHPAS control module and P/S angle sensor connectors. • Inspect for continuity between P/S angle sensor terminals B and D. • Is there continuity?	Yes	Replace the P/S angle sensor, then go to the step 7. (See STEERING GEAR AND LINKAGE DISASSEMBLY.) (See STEERING GEAR AND LINKAGE ASSEMBLY.)
5		No	Go to the next step.
6	INSPECT PID FOR P/S ANGLE SENSOR RING MALFUNCTION USING WDS OR EQUIVALENT • Turn the ignition switch off. • Connect the WDS or equivalent to the DLC-2. • Select the "STEER_RATE" PID. • Verify that the WDS display changes correctly according to steering wheel operation. • Does it change correctly?	Yes	Go to the next step.
6		No	Replace the P/S angle sensor ring (built into the steering gear valve housing), then go to the next step. (See STEERING GEAR AND LINKAGE DISASSEMBLY.) (See STEERING GEAR AND LINKAGE ASSEMBLY.)
7	VERIFY THAT THE SAME DTC IS NOT PRESENT • Reconnect all disconnected connectors. • Clear the DTC from the memory. (See Clearing DTCs Procedure.) • Is the same DTC present?	Yes	• Repeat the inspection from Step 1. • If the malfunction recurs, replace the electric power steering oil pump. (See ELECTRIC POWER STEERING OIL PUMP (ZY, LF, L3) REMOVAL/INSTALLATION.)
7		No	Go to the next step.
8	VERIFY THAT NO OTHER DTCS ARE PRESENT • Are any other DTCs output?	Yes	Go to the applicable DTC inspection. (See DTC Table.)
8		No	DTC troubleshooting completed.

**Without P/S Angle Sensor [Applied VIN (Assumed): JM0 BK10100 150354-, JM6 BK10100 150354-, JM7 BK6# 150354-]**


DTC	C1278		Steering angle sensor
DETECTION CONDITION		• The electro hydraulic power assist steering (EHPAS) control module detects that the monitor voltage from the steering angle sensor is more than 4.9 V or less than 0.8 V • The EHPAS control module detects that the two monitor voltages modulate at the same phase a specified amount of phases or more. • The EHPAS control module detects that the EHPAS sensor signal dose not change.
POSSIBLE CAUSE		• Short to power supply, open circuit, or short to ground in wiring harness between EHPAS control module terminal 3B and steering angle sensor B • Short to power supply, open circuit, or short to ground in wiring harness between EHPAS control module terminal 3D and steering angle sensor terminal C • Open circuit in wiring harness between EHPAS control module terminal 3A and steering angle sensor terminal D (with ABS) • Open circuit in wiring harness between DSC HU/CM terminal AH and steering angle sensor terminal D (with DSC) • Short circuit in wiring harness between steering angle sensor terminal A and D • Steering angle sensor malfunction. • Steering angle sensor ring has fallen off.

Diagnostic procedure


STEP	INSPECTION		ACTION
1	INSPECT PID FOR STEERING ANGLE SENSOR MALFUNCTION USING WDS OR EQUIVALENT • Turn the ignition switch off. • Connect the WDS or equivalent to the DLC-2. • Select the "STEER_RATE" PID. • Verify that the WDS display changes correctly according to steering wheel operation. • Does it change correctly?	Yes	Go to the next step.
1		No	Replace the steering angle sensor. (See CLOCK SPRING REMOVAL/INSTALLATION.)
2	INSPECT POWER SUPPLY VOLTAGE OF STEERING ANGLE SENSOR • Turn the ignition switch to the ON position (Engine off). • Measure the voltage between steering angle sensor terminal A and ground. • Is the voltage B+?	Yes	Go to the next step.
2		No	With ABS • Repair or replace the wiring harness between ignition switch and steering angle sensor terminal A, then go to the step 7. With DSC • Repair or replace the wiring harness between DSC HU/CM terminal AB and steering angle sensor terminal A, then go to the step 7.
3	INSPECT GROUND CIRCUIT OF STEERING ANGLE SENSOR FOR OPEN CIRCUIT • Turn the ignition switch off. • Disconnect the EHPAS control module (with ABS) or DSC HU/CM (with DSC) and steering angle sensor connectors. • Inspect for continuity between EHPAS control module terminal 3A (with ABS) or DSC HU/CM terminal AH (with DSC) and steering angle sensor terminal D. • Is there continuity?	Yes	Go to the next step.
3		No	Repair or replace the wiring harness between EHPAS control module terminal 3A (with ABS) or DSC HU/CM terminal AH (with DSC) and steering angle sensor terminal D, then go to the step 7.
4	INSPECT STEERING ANGLE SENSOR SIGNAL CIRCUIT FOR SHORT TO POWER • Turn ignition key to ON (engine OFF). • Measure the voltage between the EHPAS control module and body ground at the following: - Sensor 1: EHPAS control module terminal 3B and body ground - Sensor 2: EHPAS control module terminal 3D and body ground • Is voltage B+?	Yes	Repair or replace the related wiring harnesses between the EHPAS control module and steering angle sensor, then go to the step 7.
4		No	Go to next step.
5	INSPECT STEERING ANGLE SENSOR SIGNAL CIRCUIT FOR SHORT TO GROUND • Turn the ignition switch off. • Inspect continuity between the EHPAS control module and body ground at the following: - Sensor 1: EHPAS control module terminal 3B and body ground - Sensor 2: EHPAS control module terminal 3D and body ground • Is there continuity?	Yes	Repair or replace the related wiring harnesses between the EHPAS control module and steering angle sensor, then go to the step 7.
5		No	Go to the next step.
6	INSPECT SENSORS 1 AND 2 OF THE STEERING ANGLE SENSOR FOR CONTINUITY • Turn the ignition switch off. • Disconnect the EHPAS control module and steering angle sensor connectors. • Inspect for continuity between steering angle sensor terminals B and C. • Is there continuity?	Yes	Replace the steering angle sensor, then go to the step 7. (See CLOCK SPRING REMOVAL/INSTALLATION.)
6		No	Go to the next step.
7	VERIFY THAT THE SAME DTC IS NOT PRESENT • Reconnect all disconnected connectors. • Clear the DTC from the memory. (See Clearing DTCs Procedure.) • Is the same DTC present?	Yes	• Repeat the inspection from Step 1. • If the malfunction recurs, replace the electric power steering oil pump. (See ELECTRIC POWER STEERING OIL PUMP (ZY, LF, L3) REMOVAL/INSTALLATION.)
7		No	Go to the next step.
8	VERIFY THAT NO OTHER DTCS ARE PRESENT • Are any other DTCs output?	Yes	Go to the applicable DTC inspection. (See DTC Table.)
8		No	DTC troubleshooting completed.