DTC U2021 [ABS (ABS/TCS)]

id040214874600

DTC | U2021 | Engine coolant temperature
DETECTION CONDITION | • Torque reduction inhibited signal (low engine coolant temperature) received from PCM.
POSSIBLE CAUSE | • The system inhibits torque reduction while the engine coolant temperature is low to protect the engine. After the engine has warmed up, the control returns to normal. (Does not indicate a malfunction)

Diagnostic procedure

STEP | INSPECTION | ACTION
--- | --- | ---
1 | VERIFY CONDITION OF ENGINE WARMING • Is the engine warmed up? | Yes | Go to the next step.
No | Warm up the engine. • If the TCS OFF light turns off, the system is normal. • If the TCS OFF light remains illuminated, go to the next step.
2 | INSPECT FOR OTHER MALFUNCTIONS AFTER ENGINE WARMING • Warm up the engine. • Does the TCS indicator light illuminate and is DTC C1119 output? | Yes | Go to the inspection for DTC C1119. (See DTC C1119 [ABS (ABS/TCS)].)
No | • If the TCS OFF light turns off, the system is normal. • If the TCS OFF light remains illuminated, go to the next step.
3 | INSPECT FOR PCM MALFUNCTION • Inspect the PCM DTC using the WDS or equivalent. (See ON-BOARD DIAGNOSTIC TEST [L8, LF, L3].) (See ON‐BOARD DIAGNOSTIC TEST [MZR‐CD (RF Turbo)].) • Are any DTCs output? | Yes | Go to the applicable DTC inspection. (See DTC TABLE [L8, LF, L3].) (See DTC TABLE [MZR‐CD (RF Turbo)].)
No | Go to the next step.
4 | INSPECT WATER TEMPERATURE SENSOR FOR MALFUNCTION • Inspect the water temperature sensor. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [L8, LF, L3].) (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [MZR-CD (RF Turbo)].) • Is the water temperature sensor normal? | Yes | Go to the next step.
No | Replace the water temperature sensor and go to the next step. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION [L8, LF, L3].) (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION [MZR-CD (RF Turbo)].)
5 | VERIFY THAT SAME DTC IS NOT PRESENT • Clear the DTCs from the memory. (See ABS (ABS/TCS) ON‐BOARD DIAGNOSIS.) • Warm up the engine. • Is the same DTC present? | Yes | Repeat the inspection from Step 1. If the malfunction recurs, replace the ABS/TCS HU/CM. (See ABS (ABS/TCS) HU/CM REMOVAL/INSTALLATION [MTX].) (See ABS (ABS/TCS) HU/CM REMOVAL/INSTALLATION [ATX].)
No | Go to the next step.
6 | VERIFY THAT NO OTHER DTCs ARE PRESENT • Are any other DTCs output? | Yes | Go to the applicable DTC inspection. (See ABS (ABS/TCS) ON‐BOARD DIAGNOSIS.)
No | DTC troubleshooting completed.