DTC P1631 [MZ-CD 1.6 (Y6) (EURO4 emission level)]

id0102g6838700

DTC P1631

Main relay circuit malfunction -too early

DETECTION CONDITION

•  The PCM monitors the main relay signal. If any of the following conditions is detected, the PCM determines that the main relay circuit has a malfunction.

―  Main relay signal is detected too early exceeds 5 times

―  Main relay signal is not detected for 3 s

POSSIBLE CAUSE

•  Main relay connector or terminal malfunction

•  Main relay malfunction

•  Short to ground in the wiring harness between main relay terminal B and PCM terminal 241

•  PCM connector or terminal malfunction

•  Short to power supply in the wiring harness between main relay terminal B and PCM terminal 241

•  Open circuit in the wiring harness between main relay terminal B and PCM terminal 241

•  PCM malfunction

DTC P1631	Main relay circuit malfunction -too early
DETECTION CONDITION	• The PCM monitors the main relay signal. If any of the following conditions is detected, the PCM determines that the main relay circuit has a malfunction. ― Main relay signal is detected too early exceeds 5 times ― Main relay signal is not detected for 3 s
POSSIBLE CAUSE	• Main relay connector or terminal malfunction • Main relay malfunction • Short to ground in the wiring harness between main relay terminal B and PCM terminal 241 • PCM connector or terminal malfunction • Short to power supply in the wiring harness between main relay terminal B and PCM terminal 241 • Open circuit in the wiring harness between main relay terminal B and PCM terminal 241 • PCM malfunction

Diagnostic procedure

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA HAS BEEN RECORDED • Has the FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY • Verify related service repair information availability. • Is any related repair information available?	Yes	Perform repair or diagnosis according to the available repair information. • If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	VERIFY RELATED PENDING CODE AND/OR DTC • Switch the ignition to ON (engine off). • Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure. (See ON-BOARD DIAGNOSTIC TEST [MZ-CD 1.6 (Y6) (EURO4 emission level)].) • Is the other PENDING CODE/DTC also present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [MZ-CD 1.6 (Y6) (EURO4 emission level)].)
3		No	Go to the next step.
4	INSPECT MAIN RELAY CONNECTOR CONDITION • Switch the ignition to off. • Remove the main relay connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion) • Is there any malfunction?	Yes	Repair or replace the connector and/or terminals, then go to Step 10.
4		No	Go to the next step.
5	INSPECT MAIN RELAY • Inspect the main relay. (See RELAY INSPECTION.) • Is there any malfunction?	Yes	Replace the main relay, then go to Step 10.
5		No	Go to the next step.
6	INSPECT MAIN RELAY SIGNAL CIRCUIT FOR SHORT TO GROUND • Main relay is removed. • Inspect for continuity between main relay terminal B (wiring harness-side) and body ground. • Is there continuity?	Yes	Repair or replace the wiring harness for a possible short to ground, then go to Step 10.
6		No	Go to the next step.
7	INSPECT PCM CONNECTOR CONDITION • Disconnect the PCM connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion) • Is there any malfunction?	Yes	Repair or replace the connector and/or terminals, then go to Step 10.
7		No	Go to the next step.
8	INSPECT MAIN RELAY SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY • Main relay is removed. • PCM connector is disconnected. • Switch the ignition to ON (engine off). • Measure the voltage at the main relay terminal B (wiring harness-side) • Is there any voltage?	Yes	Repair or replace the wiring harness for a possible short to power supply, then go to Step 10.
8		No	Go to the next step.
9	INSPECT MAIN RELAY CIRCUIT FOR OPEN CIRCUIT • Main relay is removed. • PCM connector is disconnected. • Switch the ignition to off. • Inspect for continuity between the main relay terminal B (wiring harness-side) and PCM terminal 241 (wiring harness-side) • Is there continuity?	Yes	Go to the next step.
9		No	Repair or replace the wiring harness for a possible open circuit, then go to the next step.
10	VERIFY THAT DTC P1631 TROUBLESHOOTING IS COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the M-MDS. • Run the vehicle under the FREEZE FRAME DATA stored condition. • Is the same DTC present?	Yes	Repeat the inspection from Step 1. • If the malfunction recurs, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZ-CD 1.6 (Y6) (EURO4 emission level)].) Go to the next step.
10		No	Go to the next step.
11	VERIFY AFTER REPAIR PROCEDURE • Perform the after repair procedure. (See AFTER REPAIR PROCEDURE [MZ-CD 1.6 (Y6) (EURO4 emission level)].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [MZ-CD 1.6 (Y6) (EURO4 emission level)].)
11		No	DTC troubleshooting completed.