DTC P0337: CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT/LOW FREQUENCY Honda Passport II

Note. 58X reference signal is produced by CKP sensor.

Diagnostic Aids

An intermittent may be caused by a poor connection, rubbed-through wire insulation or a broken wire inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection, and damaged harness. Connect voltmeter to 58X reference circuit (Yellow wire) and wiggle harness and connectors. A change in voltage will indicate area of problem. If DTC cannot be duplicated, check scan tool FAILURE RECORDS to determine mileage since last DTC was set.

1. Perform On-Board Diagnostic (OBD) System Check. See BASIC DIAGNOSTIC PROCEDURES article. Read and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step.
2. Attempt to start engine. If engine starts and runs, go to next step. If engine does not start and run, see BASIC DIAGNOSTIC PROCEDURES article.
3. Using scan tool, clear DTC P0337. Start engine and allow it to idle for one minute. Read DTCs. If DTC P0337 resets, go to next step. If DTC P0337 does not reset, check for an intermittent problem. See «DIAGNOSTIC AIDS»(ref-89316-S18101638342001022800000) .
4. Turn ignition off and disconnect CKP sensor. Turn ignition on. Connect a voltmeter between 5-volt reference and sensor ground terminals at harness connector. If reading is 4-6 volts, go to step 7 . If reading is not 4-6 volts, go to next step.
5. Backprobe voltmeter between PCM harness connector 5-volt reference circuit (Brown wire on 3.2L, or Yellow/Red wire on 3.5L) and ground terminals. If reading is 4-6 volts, go to next step. If reading is not 4-6 volts, go to step 10 .
6. Check CKP sensor 5-volt reference circuit (Brown wire on 3.2L, or Yellow/Red wire on 3.5L) and ground circuit (Green wire) between CKP sensor and PCM for an open, short to ground or short to power. Repair as necessary. Retest system.
7. Turn ignition off and disconnect PCM and CKP sensor harness connectors. Check for an open or short to ground in 58X reference circuit (Yellow wire) between CKP sensor connector and PCM harness connector. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
8. Reconnect PCM and CKP sensor harness connectors. Using voltmeter, measure voltage of 58X reference circuit (Brown wire on 3.2L, or Yellow/Red wire on 3.5L) at PCM harness connector while cranking engine. If reading is about 2.5 volts, go to step 10 . If reading is not about 2.5 volts, go to next step.
9. Inspect connections at CKP sensor. Repair connections as necessary. If connections are okay, replace CKP sensor. Retest system.
10. Inspect connections at PCM. Repair connections as necessary. If connections are okay, replace PCM. Retest system.

An intermittent may be caused by a poor connection, rubbed-through wire insulation or a broken wire inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection, and damaged harness. Disconnect PCM connector. Connect voltmeter to CMP signal circuit and wiggle harness and connectors. A change in voltage will indicate area of problem. If DTC cannot be duplicated, check scan tool FAILURE RECORDS to determine mileage since last DTC was set.

1. Perform On-Board Diagnostic (OBD) System Check. See BASIC DIAGNOSTIC PROCEDURES article. Read and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step.
2. Turn ignition on. Using scan tool, read and record FAIL RECORDS data for DTC P0341. Operate vehicle within FAILURE RECORDS conditions. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0341 FAILED THIS IGN, go to next step. If scan tool does not display DTC P0341 FAILED THIS IGN, check for an intermittent problem. See «DIAGNOSTIC AIDS»(ref-89316-S24725320152001022800000) .
3. Disconnect CMP sensor. Measure voltage between sensor ground circuit (Green wire) and sensor voltage reference circuit (Yellow/Red wire) at CMP sensor harness connector. If reading is 4-6 volts, go to next step. If reading is not 4-6 volts, go to step 5 .
4. Measure voltage between CMP sensor signal circuit (Blue wire on 3.2L, or Blue and White wires on 3.5L) and sensor ground circuit (Green wire) at CMP sensor harness connector. If reading is 4-6 volts, go to step 11 . If reading is not 4-6 volts, go to step 8 .
5. If voltage measured in step 3) was less than 4-6 volts, go to next step. If voltage in step 3 was greater than 4-6 volts, repair short to power in CMP sensor voltage reference circuit. Retest system.
6. Inspect CMP sensor for poor connection. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
7. Turn ignition off. Disconnect PCM and CMP sensor harness connectors. Inspect sensor voltage reference circuits (Yellow/Red wire) for an open between ignition control module and CMP sensor. If a problem is found, repair as necessary. Retest system. If no problem is found, go to step 9 .
8. Turn ignition off. Disconnect PCM harness connectors and leave CMP sensor disconnected. Turn ignition on. Using a DVOM, check CMP sensor signal circuit (Blue wire on 3.2L, or Blue and White wires on 3.5L) for an open or short to power. Check CMP sensor input circuit for a short to ground. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
9. Check for an open or short in CMP sensor ground circuit. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
10. Check for poor connection at PCM. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
11. Reconnect PCM and CMP sensor harness connectors. Using a voltmeter, backprobe sensor connector at CMP signal circuit (Blue wire on 3.2L, or Blue and White wires on 3.5L). Crank engine and monitor voltage. If voltage toggles between zero and 4 volts, replace PCM. Retest system. If voltage does not toggle between zero and 4 volts, leave voltmeter connected and go to next step.
12. Leaving sensor wiring harness connected, remove CMP sensor. Place a magnet on CMP sensor large enough to cover face of sensor. If voltmeter reads about zero volts, replace faulty or missing sensor magnet. If voltmeter does not read about zero volts, replace CMP sensor. Retest system.

An intermittent may be caused by a poor connection, rubbed-through wire insulation or a broken wire inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection, and damaged harness. Disconnect PCM connector. Connect voltmeter to CMP signal circuit and wiggle harness and connectors. A change in voltage will indicate area of problem. If DTC cannot be duplicated, check scan tool FAILURE RECORDS to determine mileage since last DTC was set.

1. Perform On-Board Diagnostic (OBD) System Check. See BASIC DIAGNOSTIC PROCEDURES article. Read and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step.
2. Turn ignition on. Using scan tool, read and record FAIL RECORDS data for DTC P0342. Operate vehicle within FAILURE RECORDS conditions. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0342 FAILED THIS IGN, go to next step. If scan tool does not display DTC P0342 FAILED THIS IGN, check for an intermittent problem. See «DIAGNOSTIC AIDS»(ref-89316-S02522952732001022800000) .
3. Disconnect CMP sensor. Turn ignition on. Measure voltage between sensor ground and CMP sensor harness connector voltage reference circuit (Brown and Yellow/Red wires on 3.2L, or Yellow/Red wires on 3.5L) and sensor ground. If reading is 4-6 volts, go to step 7 . If reading is not 4-6 volts, go to next step.
4. Turn ignition off. Disconnect PCM and CMP sensor harness connectors. Check for poor connections at CMP sensor. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
5. Check for poor connection at PCM. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
6. Inspect CMP sensor voltage reference circuit (Brown and Yellow/Red wires on 3.2L, or Yellow/Red wire on 3.5L) for an open or short to ground. Inspect CMP sensor ground circuit for an open or short to power. Repair as necessary. Retest system.
7. With ignition on and engine off, measure voltage between CMP sensor signal circuit (Blue wire on 3.2L, or Blue and White wires on 3.5L) and sensor ground circuit at CMP sensor harness connector. If reading is not 4-6 volts, go to step 9 . If reading is about 4-6 volts, got to next step.
8. Turn ignition off. Disconnect PCM harness connectors. Turn ignition on. Connect a voltmeter between ground and CMP sensor signal circuit (Blue wire on 3.2L, or Blue and White wires on 3.5L) at PCM harness connector. Monitor voltage while repeatedly touching CMP sensor signal circuit at CMP sensor connection with a test light to ground. If voltmeter displays voltage toggling between zero and 5 volts when test light is touched to CMP sensor signal circuit, leave voltmeter connected and go to step 12 . If voltage is not as specified, go to next step.
9. Ensure PCM is still disconnected. Turn ignition on. Connect test light between battery voltage and CMP sensor signal circuit (Blue wire on 3.2L, or Blue and White wires on 3.5L) at PCM harness connector. If test light comes on, locate and repair short to ground in CMP signal circuit. Retest system. If test light does not come on, go to next step.
10. Probe CMP sensor signal circuit (Blue wire on 3.2L, or Blue and White wires on 3.5L) with a test light connected to ground. If test light comes on, locate and repair short to voltage in CMP sensor signal circuit. Retest system. If test light does not come on, go to next step.
11. Turn ignition off. Disconnect CMP sensor harness connector. Using an ohmmeter, check CMP sensor signal circuit (Blue wire on 3.2L, or Blue and White wires on 3.5L) for an open. If problem is found, repair as necessary. Retest system.
12. Remove CMP sensor and reconnect harness connector. Place a magnet on CMP sensor large enough to cover face of sensor. Observe voltmeter. If reading is about zero volts, go to next step. If reading is not about zero volts, replace CMP sensor. Retest system.
13. Reinstall CMP sensor, leaving voltmeter connected. Crank engine and observe voltmeter. If voltage toggles between zero and 4 volts, replace PCM. If voltage does not toggle between zero and 4 volts, replace faulty or missing CMP sensor magnet. Retest system.

An intermittent may be caused by a poor connection, rubbed-through wire insulation or a broken wire inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection, and damaged harness. Using scan tool, monitor DTC P0351-P0356 and wiggle harness and connectors. A change in voltage will indicate area of problem. If DTC cannot be duplicated, check scan tool FAILURE RECORDS to determine mileage since last DTC was set.

1. Perform On-Board Diagnostic (OBD) System Check. See BASIC DIAGNOSTIC PROCEDURES article. Read and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step.
2. Turn ignition on. Using scan tool, read and record FAIL RECORDS data for DTCs P0351-P0356. Operate vehicle within FAILURE RECORDS conditions. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0351-P0356, go to next step. If scan tool does not display any DTC, check for an intermittent problem. See «DIAGNOSTIC AIDS»(ref-89316-S09754044102001022800000) .
3. Check ignition control module for poor connection or damaged terminals. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
4. Check PCM harness connector for poor connection or damaged terminals. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
5. Turn ignition on. Backprobe voltmeter between ground and affected ignition control circuit at PCM harness connector. If reading is 25-55 mV, go to next step. If reading is not 25-55 mV, go to step 8 .
6. Start engine and let idle. Backprobe voltmeter between ground and ignition control circuit at PCM harness connector for cylinder being tested. If reading toggles between 100 and 180 mV, go to next step. If reading does not toggle between 100 and 180 mV, replace PCM. Retest system.
7. Turn ignition off. Disconnect 3-pin and/or 5-pin connectors at ignition control module/ignition coil. Measure voltage of affected ignition control circuit at ignition control module while cranking engine. If reading is 200-1200 mV, replace ignition control module. If reading is not 200-1200 mV, repair open in affected ignition control circuit. Retest system.
8. Turn ignition off. Disconnect PCM and ignition control module harness connectors. Using ohmmeter, check affected ignition control circuit for a short to ground, voltage, or open circuit. Repair as necessary. If circuit is okay, go to next step.
9. Turn ignition on. Using voltmeter, check affected ignition control circuit for a short to voltage. Repair as necessary. If circuit is okay, replace PCM. Retest system.

An intermittent may be caused by a poor connection, rubbed-through wire insulation or a broken wire inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection, and damaged harness. Using scan tool, monitor ACTUAL EGR POSITION and wiggle harness and connectors. A change in voltage will indicate area of problem. If DTC cannot be duplicated, check scan tool FAILURE RECORDS to determine mileage since last DTC was set.

1. Perform On-Board Diagnostic (OBD) System Check. See BASIC DIAGNOSTIC PROCEDURES article. Read and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step.
2. If DTC P1404 is also set, go to «DTC P1404: EGR CLOSED STUCK»(ref-89316-S32137109392001022800000) . If DTC P1404 is not set, go to next step.
3. Start engine. Using scan tool, monitor MAP signal. Quickly press throttle half way down and release. If scan tool value does not make an immediate large change, replace MAP sensor. If scan tool value made an immediate large change, go to next step.
4. Inspect exhaust system for modifications or leaks. If a problem is found, repair as necessary and go to step 7 . If a problem is not found, go to next step.
5. Remove EGR valve and check pintle, valve and passages and adapter for excessive deposits or restriction. Check EGR valve gasket and pipes for leaks. If a problem is found, repair as necessary and go to step 7 . If no problem is found, go to next step.
6. Remove EGR inlet and outlet pipes from exhaust and intake manifolds. Inspect manifold EGR ports and pipes for blockage. If a problem is found, repair as necessary, then go to next step. If no problem is found, check for an intermittent problem. See «DIAGNOSTIC AIDS»(ref-89316-S22926311402001022800000) .
7. Read and record FAIL RECORDS data for DTC P0401. Clear DTCs. Start engine and monitor system information screen while moving connectors and wiring harnesses related to EGR valve. If scan tool displays DTC P0401 FAILED THIS IGN, go to last step completed in this DTC test. If scan tool does not display DTC P0401 FAILED THIS IGN, repair is complete.

An intermittent may be caused by a poor connection, rubbed-through wire insulation or a broken wire inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection, and damaged harness. Using scan tool, monitor ACTUAL EGR POSITION and wiggle harness and connectors. A change in voltage will indicate area of problem. If DTC cannot be duplicated, check scan tool FAILURE RECORDS to determine mileage since last DTC was set.

1. Perform On-Board Diagnostic (OBD) System Check. See BASIC DIAGNOSTIC PROCEDURES article. Read and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step.
2. Turn ignition on. Review and record scan tool FAILURE RECORDS data. Operate vehicle within FAILURE RECORDS conditions. Using scan tool, monitor SPECIFIC DTC information for DTC P0402 until DTC P0402 test runs. Note result. If scan tool indicates DTC P0402 failed this ignition, go to next step. If scan tool indicates DTC P0402 did not fail this ignition, see «DIAGNOSTIC AIDS»(ref-89316-S06553302222001022800000) .
3. Disconnect EGR valve harness connector. Check EGR valve and connector for damaged pins or terminals. Repair as necessary. If connector pins and terminals are okay, go to next step.
4. Remove EGR valve. Check if foreign material is present between seat and pintle. If foreign material is present, go to next step. If foreign material is not present, go to step 6 .
5. Remove EGR valve foreign material. Check pintle and seat for damage. If damage was present that would effect operation of EGR valve, go to step 7 . If no damage was present that would effect operation of EGR valve, go to next step.
6. Reinstall EGR valve. Ensure ignition is off. Install scan tool. Start and run engine at idle. Using scan tool, check EGR operation. If EGR operates correctly, system is okay. If EGR does not operate correctly, go to next step.
7. Replace EGR valve. If DTC P0402 still fails SPECIFIC DTC test on scan tool, replace PCM.

An intermittent may be caused by a poor connection, rubbed-through wire insulation or a broken wire inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection, and damaged harness. Using scan tool, monitor ACTUAL EGR POSITION and wiggle harness and connectors. A change in voltage will indicate area of problem. If DTC cannot be duplicated, check scan tool FAILURE RECORDS to determine mileage since last DTC was set.

1. Perform On-Board Diagnostic (OBD) System Check. See BASIC DIAGNOSTIC PROCEDURES article. Read and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step.
2. Turn ignition on. Review and record scan tool FAILURE RECORDS data. Operate vehicle within FAILURE RECORDS conditions. Using scan tool, monitor SPECIFIC DTC information for DTC P0404 until DTC P0404 test runs. Note result. If scan tool indicates DTC P0404 failed this ignition, go to next step. If scan tool indicates DTC P0404 did not fail this ignition, see «DIAGNOSTIC AIDS»(ref-89316-S25088616162001022800000) .
3. Disconnect EGR valve harness connector. Check EGR valve and connector for damaged pins or terminals. Repair as necessary. If connector pins and terminals are okay, go to next step.
4. Remove EGR valve. Check if carbon deposits are present on EGR shaft. If carbon is present, go to next step. If carbon is not present, go to step 6 .
5. Clean EGR valve shaft and inside of EGR valve. Check pintle and seat for damage. If damage was present that would effect operation of EGR valve, go to step 7 . If no damage was present that would effect operation of EGR valve, go to next step.
6. Reinstall EGR valve. Ensure ignition is off. Install scan tool. Start and run engine at idle. Using scan tool, check EGR operation. If EGR operates correctly, system is okay. If EGR does not operate correctly, go to next step.
7. Replace EGR valve. If DTC P0404 still fails SPECIFIC DTC test on scan tool, replace PCM.

An intermittent may be caused by a poor connection, rubbed-through wire insulation or a broken wire inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection, and damaged harness. Using scan tool, monitor ACTUAL EGR POSITION and wiggle harness and connectors. A change in voltage will indicate area of problem. If DTC cannot be duplicated, check scan tool FAILURE RECORDS to determine mileage since last DTC was set.

1. Perform On-Board Diagnostic (OBD) System Check. See BASIC DIAGNOSTIC PROCEDURES article. Read and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step.
2. Turn ignition on. Review and record scan tool FAILURE RECORDS data. Operate vehicle within FAILURE RECORDS conditions. Using scan tool, monitor SPECIFIC DTC information for DTC P0405 until DTC P0405 test runs. Note result. If scan tool indicates DTC P0405 failed this ignition, go to next step. If scan tool indicates DTC P0405 did not fail this ignition, see «DIAGNOSTIC AIDS»(ref-89316-S10559235602001022800000) .
3. Disconnect EGR valve harness connector. Check EGR valve and connector for damaged pins or terminals. Repair as necessary. If connector pins and terminals are okay, go to next step.
4. Disconnect EGR valve harness connector. Turn ignition on. Connect voltmeter between 5-volt reference connector terminal "D" (Red wire) and ground terminal "B" (Green wire). If about 4-6 volts are present, go to next step. If about 4-6 volts are not present, go to step 6 .
5. Turn ignition off. Measure resistance between EGR connector terminals "B" (Green wire) and "D" (Red wire). If 5-5.5 k/ohms are present, go to step 6 . If 5-5.5 k/ohms are not present, go to step 7 .
6. Turn ignition on. Backprobe voltmeter between ground and PCM connector terminal A1 (Red wire). If 4-6 volts are present, repair wiring as necessary. If 4-6 volts are not present, go to step 12 .
7. Connect ohmmeter between EGR connector pintle position pin connector terminal "C" (Yellow/Red wire) and ground terminal "B" (Green wire). If resistance is 1-1.25 k/ohms, go to step 10 . If resistance is not 1-1.25 k/ohms, go to step 12 .
8. Turn ignition on. Backprobe voltmeter between EGR connector pintle position pin connector terminal "C" (Yellow/Red wire) and ground terminal "B" (Green wire). If voltage is less than .1 volt, go to step 12 . If voltage is .1 volt or more, go to next step.
9. Backprobe voltmeter between PCM connector terminals B7 (Yellow/Red wire) and D8 (Green wire). If voltage is less than .1 volt, go to next step. If voltage is .1 volt or more, go to step 12 .
10. Turn ignition off. Disconnect EGR harness connector. Check for short circuit between Yellow/Red and Green wires. Repair wiring as necessary. If wiring is okay, go to step 12 .
11. Disconnect PCM connector. Turn ignition on. Measure voltage between EGR pintle position connector terminal "C" (Yellow/Red wire) and ground. If less than .1 volt is present, go to next step. If greater than .1 volt is present, check wiring for a short circuit. Repair wiring as necessary. If wiring is okay, go to next step.
12. Replace EGR valve. If DTC P0405 still fails scan tool test, check PCM connectors for poor terminal contact. Repair as necessary. If terminal contact is okay, replace PCM.

An intermittent may be caused by a poor connection, rubbed-through wire insulation or a broken wire inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection, and damaged harness. Using scan tool, monitor ACTUAL EGR POSITION and wiggle harness and connectors. A change in voltage will indicate area of problem. If DTC cannot be duplicated, check scan tool FAILURE RECORDS to determine mileage since last DTC was set.

1. Perform On-Board Diagnostic (OBD) System Check. See BASIC DIAGNOSTIC PROCEDURES article. Read and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step.
2. Turn ignition on. Review and record scan tool FAILURE RECORDS data. Operate vehicle within FAILURE RECORDS conditions. Using scan tool, monitor SPECIFIC DTC information for DTC P0406 until DTC P0406 test runs. Note result. If scan tool indicates DTC P0406 failed this ignition, go to next step. If scan tool indicates DTC P0406 did not fail this ignition, see «DIAGNOSTIC AIDS»(ref-89316-S30030673402001022800000) .
3. Disconnect EGR valve harness connector. Check EGR valve and connector for damaged pins or terminals. Repair as necessary. If connector pins and terminals are okay, go to next step.
4. Disconnect EGR valve harness connector. Turn ignition on. Connect voltmeter between 5-volt reference connector terminal "D" (Red wire) and ground terminal "B" (Green wire). If about 4-6 volts are present, go to step 6 . If about 4-6 volts are not present, go to next step.
5. Turn ignition on. Backprobe voltmeter between ground and PCM connector terminal A1 (Red wire). If about 4-6 volts are present, repair open circuit in Red wire. If about 4-6 volts are not present, replace PCM.
6. Turn ignition off. Measure resistance between EGR connector terminals "B" (Green wire) and "D" (Red wire). If resistance is 5-5000 ohms, go to next step. If resistance is not 5-5000 ohms, replace EGR valve.
7. Measure resistance between EGR connector terminals "B" (Green wire) and "C" (Yellow/Red wire). If continuity is present, go to next step. If continuity is not present, replace EGR valve.
8. Disconnect EGR harness at PCM connector. Check for short circuit between PCM connector terminals A1 (Red wire) and B7 (Yellow/Red wire). If wiring is okay, go to next step. If wiring is shorted, replace EGR harness.
9. Turn ignition on. Backprobe voltmeter between ground and EGR valve terminal "C" (Yellow/Red wire). If greater than 4.8 volts are present, go to next step. If 4.8 volts or less are present, replace PCM.
10. Reconnect EGR harness connector. Backprobe voltmeter between ground and PCM connector terminal B7 (Yellow/Red wire). If voltage is greater than 4.8 volts, replace PCM. If voltage is 4.8 volts or less, replace EGR harness.