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Test 8: Crankshaft Position (CKP) Sensor

TEST 8: CRANKSHAFT POSITION (CKP) SENSOR

TEST 8 CRANKSHAFT POSITION (CKP) SENSOR
STEP  INSPECTION  ACTION 
1 CHECK CKP+ CKP- CONTINUITY
  • Disconnect the CKP sensor and PCM.
  • Measure resistance of CKP(+) pin 21 (DL) and CKP(-) pin 22 (GY) circuits between the PCM harness connector and the CKP harness connector.
  • Is resistance greater than 5 ohms? 
 Yes Repair open circuit.
No Go to step 2.
2 CHECK FOR CKP+ BIAS VOLTAGE FAULT
  • Key ON, Engine OFF (KOEO).
  • Reconnect the PCM.
  • Measure voltage between CKP(+) pin 21 (DL) at the CKP connector and battery negative post.
  • Key OFF.
  • Was voltage greater than 1.0 volt but less than 2.0 volts? 
 Yes Go to step 3.
No Bias Fault. Go step 15.
3 CHECK CKP-BIAS VOLTAGE FAULT
  • Key ON, Engine OFF (KOEO).
  • Measure voltage between CKP(-) pin 22 (GY) at the CKP connector and battery negative post.
  • Was voltage between 1.0 and 2.0 volts? 
 Yes Key OFF.
Go to step 7.
No Bias fault.
Go to step 4.
4 DETERMINE IF BIAS HIGH OR BIAS LOW FAULT
  • Was bias voltage reading in step 3 less than 1.0 volt? 
 Yes Bias low fault.
Go to step 5.
No Bias high fault.
Go to step 6.
5 CHECK CKP- CIRCUIT FOR SHORT TO GROUND IN HARNESS
  • Disconnect PCM.
  • Measure resistance between CKP(-) pin 22 (GY) at the PCM connector and battery negative post.
  • Is the resistance greater than 10K ohms? 
 Yes Replace PCM. See COMPUTERIZED ENGINE CONTROLS .
No Repair short circuit.
6 CHECK CKP-CIRCUIT FOR SHORT TO POWER IN HARNESS
  • Disconnect PCM.
  • Key ON, Engine OFF (KOEO).
  • Measure voltage of CKP(-) pin 22 (GY) at the PCM connector and battery negative post.
  • Is voltage less than 0.5 volt? 
 Yes Replace PCM. See COMPUTERIZED ENGINE CONTROLS .
No Repair short circuit.
7 CHECK CKP SENSOR AMPLITUDE AT PCM
  • Reconnect CKP sensor.
  • Disconnect PCM.
  • Measure voltage between CKP(+) pin 21 (DL) and CKP(-) pin 22 (GY) at the PCM connector when cranking engine.
  • Key OFF.
  • Was settled AC voltage reading greater than 0.4 volt? 
 Yes CKP circuit is OK.
Go to step 13.
No Amplitude fault.
Go to step 8.
8 CHECK CKP CIRCUIT RESISTANCE FOR AMPLITUDE FAULT
  • Measure resistance between CKP(+) pin 21 (DL) and CKP(-) pin 22 (GY) at the PCM connector.
  • Is resistance between 300 and 800 ohms? 
 Yes Go to step 12.
No Go to step 9.
9 DETERMINE IF RESISTANCE HIGH OR RESISTANCE LOW FAULT
  • Was the resistance from step 8 less than 300 ohms? 
 Yes Low resistance fault.
Go to step 10.
No Replace CKP sensor.
See IGNITION SYSTEM .
10 CHECK CKP+ FOR SHORT TO CKP-
  • Disconnect CKP sensor.
  • Measure resistance between the CKP+ pin 21 and CKP- pin 22 at CKP connector.
  • Is resistance less than 5 ohms? 
 Yes Go to step 11.
No Repair open circuit.
11 CHECK CKP SENSOR AND PULSE WHEEL
  • Check pulse wheel and CKP sensor visually for damage.
  • Is CKP sensor and pulse wheel OK? 
 Yes Replace CKP sensor.
See IGNITION SYSTEM .
No Repair or replace damaged parts.
12 CHECK FOR OPEN OR SHORT IN PCM
  • Disconnect the CKP sensor and reconnect the PCM.
  • Key OFF.
  • Measure the resistance between the CKP+ pin 21 (DL) and CKP- pin 22 (GY) at the CKP harness connector.
  • Is the resistance between 16K and 24K ohms? 
 Yes Go to step 14.
No Replace the PCM.
Replace PCM. See COMPUTERIZED ENGINE CONTROLS .
13 CHECK CKP+ CIRCUIT FOR SHORT TO CKP-CIRCUIT IN HARNESS
  • Disconnect CKP sensor.
  • Measure resistance between CKP+ pin 21 (DL) and CKP- pin 22 (GY) at the PCM connector.
  • Is resistance greater than 1, 000 ohms? 
 Yes Replace CKP sensor.
See IGNITION SYSTEM .
No Repair short circuit.
14 DETERMINE IF BIAS VOLTAGE HIGH OR BIAS VOLTAGE LOW FAULT
  • Was bias voltage reading in step 2 less than 1.0 volt? 
 Yes Low bias voltage fault.
Go to step 15.
No High bias voltage fault.
Go to step 16.
15 CHECK CKP+ CIRCUIT FOR SHORT TO GROUND IN HARNESS
  • Disconnect PCM.
  • Measure resistance between CKP+ pin 21 (DL) and battery negative post.
  • Is each resistance greater than 10K ohms? 
 Yes Replace PCM. See COMPUTERIZED ENGINE CONTROLS .
No Repair short circuit.
16 CHECK CKP+ CIRCUIT FOR SHORT TO POWER IN HARNESS
  • Disconnect PCM.
  • Key ON, Engine OFF (KOEO).
  • Measure voltage of CKP+ pin 21 (DL) and battery negative post.
  • Is voltage less than 0.5 volt? 
 Yes Replace PCM. See COMPUTERIZED ENGINE CONTROLS .
No Repair short circuit.
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