Circuit Description
The VCM constantly monitors the linear EGR valve pintle position sensor in order to ensure that the valve is responding properly to the commands from the VCM. The DTC P1406 is a type A DTC.
Conditions for Setting the DTC
The following conditions will set the DTC:
| • | EGR pintle position signal indicates a voltage out of the normal range of the pintle position sensor, or a signal that is 10% greater or less than the VCM commanded position |
| • | Ignition voltage greater than 9 volts |
Action Taken When DTC Sets
If a current DTC P1406 sets during 2 consecutive test cycles, the VCM turns ON the MIL.
Diagnostic Aids
A poor connection or a rubbed-through wire insulation may cause an intermittent condition. Check for the following conditions:
| • | A poor connection or a damaged harness - Inspect VCM harness connectors for backed out terminals BLK 18, GRY 27, GRY19, or RED 10 for the following items: |
| • | Improper mating |
| • | Broken locks |
| • | Improperly formed or damaged terminals |
| • | A poor terminal to wire connection |
| • | A damaged harness |
Intermittent test - If the connections and the harness check OK, monitor a digital voltmeter connected between the affected terminals and the ground while moving the related connectors and the wiring harness. If the failure is induced, the voltage reading will change.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
Checks for an EGR valve sticking partially open or an incorrect pintle position sensor feedback signal.
-
This step determines if this DTC was set during an intermittent condition. If the fault that set this DTC is not present, check for other stored DTCs.
-
Checks the EGR valve driver in the VCM and the EGR Control circuit.
-
This checks for EGR Valve Ignition Feed at the EGR valve.
-
Clearing the DTC Information is a very important step in this diagnostic. This allows the EGR Valve to relearn a new minimum pintle position.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 |
Important: Before clearing the DTCs, use the scan tool in order to record the Freeze Frame and the Failure Records for reference. This data will be lost when the Clear DTC Information function is used. Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
Does the scan tool display the specified value? | 0% | |||
Does the Actual EGR Position follow the Commanded Position? | 20%, 50%, 70%,100% | Go to Diagnostic Aids | ||
4 |
Does the Actual EGR Position fluctuate severely? | 30% | ||
Is the test light ON? | 100% | |||
Is the test light ON? | -- | |||
7 |
Was a problem found? | -- | ||
8 | Repair the faulty connections or open in the EGR Valve Control circuit as necessary. Refer to Wiring Repairs in Electrical Diagnosis. Is the action complete? | -- | -- | |
9 | Is DTC P0108 also set? | -- | Go to DTC P0108 Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage | |
10 | Disconnect the EGR Valve electrical connector. Is the Actual EGR Valve Position at the specified value? | 0% | ||
11 | Check for a short to voltage in the EGR Pintle Position circuit. Was a problem found? | -- | ||
12 | Repair short to voltage in the EGR Pintle Position circuit. Refer to Wiring Repairs in Electrical Diagnosis. Is the action complete? | -- | -- | |
13 | Check for a blown EGR Ignition Feed fuse. Was the EGR Ignition Feed fuse blown? | -- | ||
14 | Replace EGR Ignition Feed fuse. Is the action complete? | -- | -- | |
15 | Repair the short to ground in the EGR Ignition Feed circuit. Refer to Wiring Repairs in Electrical Diagnosis. Is the action complete? | -- | -- | |
16 | Repair the open EGR Ignition Feed circuit. Refer to Wiring Repairs in Electrical Diagnosis. Is the action complete? | -- | -- | |
17 |
Is the test light ON? | -- | ||
18 |
Is the test light ON? | -- | ||
19 |
Is the test light ON? | -- | ||
20 | Repair short to ground in the EGR Valve Control circuit. Refer to Wiring Repairs in Electrical Diagnosis. Is the action complete? | -- | -- | |
21 | Check for a faulty connection at the EGR valve harness connector. Was a problem found? | -- | ||
22 | Repair the faulty connection at the EGR valve harness connector. Refer to Wiring Repairs in Electrical Diagnosis. Is the action complete? | -- | -- | |
23 | Connect a DMM J 39200 between the EGR Valve connector terminals B and D. Is the voltage near the specified value? | 5.0V | ||
24 | Connect a DMM J 39200 between the EGR harness connector terminal D and a known good ground. Is the voltage at the specified value? | 5.0V | ||
25 | Check for open in EGR Sensor Ground circuit and repair as necessary. Refer to Wiring Repairs in Electrical Diagnosis. Was repair necessary? | -- | ||
26 | Check for open in EGR 5 Volt reference circuit and repair as necessary. Refer to Wiring Repairs in Electrical Diagnosis. Was a repair necessary? | -- | ||
27 |
Is the test light ON? | -- | ||
28 | Check for a short to ground in the EGR Pintle Position circuit. Was a problem found? | -- | ||
29 | Repair the short to ground in the EGR Pintle Position circuit. Refer to Wiring Repairs in Electrical Diagnosis. Is the action complete? | -- | -- | |
30 | Using proper test adapters from Connector Test Adapter kit J 35616 , install a jumper between terminals D and C of the EGR harness connector. Is the Actual EGR Position near the specified value? | 100% | ||
31 |
Was a problem found? | -- | ||
32 | Repair the open or poor connection in the EGR pintle position circuit . Refer to Wiring Repairs in Electrical Diagnosis. Is the action complete? | -- | -- | |
33 | Replace the EGR valve. Refer to EGR Valve Replacement in Repair Instructions. Is the action complete? | -- | -- | |
34 |
Is the test light ON? | -- | ||
35 | Repair open in ignition feed circuit to Pin 4 of the C1 (Blue) VCM connector. Refer to Wiring Repairs in Electrical Diagnosis. Is the action complete? | -- | -- | |
36 | Check for poor connections at the VCM harness connectors and repair as necessary. Refer to Wiring Repairs in Electrical Diagnosis. Was a repair necessary? | -- | ||
37 |
Important: Program the new VCM. Refer to VCM Replacement/Programming (With KS Calibration PROM) in Repair Instructions. Replace the VCM. Is the action complete? | -- | -- | |
Does scan tool indicate that this diagnostic ran and passed? | -- | |||
39 | Use the scan tool in order to display the Capture Info and the Review Capture Info functions. Are there any DTCs displayed that have not been diagnosed? | -- | Go to the applicable DTC table | System OK |
Test Description
The numbers below refer to the step umbers on the diagnostic table.
-
Checks for an EGR valve sticking partially open or an incorrect pintle position sensor feedback signal.
-
Ensures that the VCM is capable of controlling EGR pintle position and is reading the pintle position feedback signal properly.
-
Checks the EGR valve driver in the VCM and the EGR Control signal circuit.
-
The checks for an incorrect EGR pintle position sensor input signal. This test verifies a 5 volt reference at the EGR valve.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 |
Important: Before clearing DTCs use the scan tool to record the freeze frame and failure records for reference, as data will be lost when the Clear Info function is used. Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
Does the scan tool display the specified value? | 0% | |||
Is it close at all commanded positions? | -- | Go to Diagnostic Aids | ||
Is the test light ON? | -- | |||
Is the test light ON? | -- | |||
6 |
Was a problem found? | -- | ||
7 | Repair the faulty connections or open in the EGR Low circuit as necessary. Refer to Wiring Repairs in Engine Electrical. Is the action complete? | -- | -- | |
8 |
Is the display at the specified value? | 0% | ||
9 | Is DTC P0108 also set? | -- | Go to DTC P0108 Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage | |
10 | Check for a short to voltage in the EGR pintle position circuit. Was a problem found? | -- | ||
11 | Repair short to voltage in the EGR pintle position circuit. Refer to Wiring Repairs in Engine Electrical. Is the action complete? | -- | -- | |
12 | Check for a blown EGR ignition feed fuse. Was the EGR ignition feed fuse blown? | -- | ||
13 | Replace EGR ignition feed fuse. Is the action complete? | -- | -- | |
14 | Repair the short to ground in the EGR high circuit. Refer to Wiring Repairs in Engine electrical. Is the action complete? | -- | -- | |
15 | Repair the open EGR high circuit. Refer to Wiring Repairs in Engine Electrical. Is the action complete. | -- | -- | |
16 |
Is the test light ON? | -- | ||
17 | Check for an open EGR pintle position ground circuit. Was a problem found? | -- | ||
18 | Repair the open in the EGR pintle position ground circuit. Refer to Wiring Repairs in Engine Electrical. Is the action complete? | -- | -- | |
19 |
Is the test light ON? | -- | ||
20 |
Is the test light ON? | -- | ||
21 | Check for short to ground in the EGR low circuit. Was a problem found? | -- | ||
22 | Repair short circuit to ground in the EGR low circuit. Refer to Wiring Repairs in Engine Electrical. Is the action complete? | -- | -- | |
23 | Check for a faulty connection at the EGR valve harness connector. Was a problem found? | -- | ||
24 | Repair the faulty connection at the EGR valve harness connector. Refer to Wiring Repairs in Engine Electrical. Is the action complete? | -- | -- | |
25 | Replace the EGR valve. Refer to Exhaust Gas Recirculation Valve Replacement . Is the action complete? | -- | -- | |
26 | Connect a J 39200 between the EGR valve connector terminal B and D. Is the voltage approximately at the specified value? | 5.0 V | ||
27 | Connect a J 39200 between the VCM harness connector terminal 5 V Reference circuit and ground. Is the voltage at the specified value? | 5.0 V | ||
28 | Check for a faulty connection at the VCM harness connector terminal 5 V Reference circuit. Was a problem found? | -- | ||
29 | Repair the faulty connection at the VCM harness connector terminal 5V Reference circuit. Refer to Wiring Repairs in Engine Electrical. Is the action complete? | -- | -- | |
30 | Repair the open EGR pintle position 5 volt reference. Refer to Wiring Repairs in Engine Electrical. Is the action complete? | -- | -- | |
31 |
Is the test light ON? | -- | ||
32 | Check for a short to ground in the EGR pintle position circuit. Was a problem found? | -- | ||
33 | Repair the short to ground in the EGR pintle position circuit. Refer to Wiring Repairs in Engine electrical. Is the action complete? | -- | -- | |
34 |
Is the voltage within the specified value? | 3.5-5.0 V | ||
35 |
Was a problem found? | -- | ||
36 | Check for poor connection at the VCM harness connector terminal Pintle Position circuit. Was a problem found? | -- | ||
37 | Repair the open in the EGR pintle position circuit. Refer to Wiring Repairs . Is the action complete? | -- | -- | |
38 | Repair connection at the VCM harness connector terminal Pintle Position circuit. Refer to Wiring Repairs in Engine Electrical. Is the action complete? | -- | -- | |
39 | Replace VCM. Important: If the VCM is faulty, the new VCM must be programmed. Refer to VCM Replacement/Programming (With KS Calibration PROM) . Is the action complete? | -- | -- | |
40 |
Does scan tool indicate that this diagnostic ran and passed? | -- | ||
41 | Using the scan tool, select the Capture Info and the Review Info. Are any DTCs displayed that have not been diagnosed? | -- | Go to The Applicable DTC Table | System OK |
