1997 PCED OBDII-Diesel
SECTION 5C: Pinpoint Tests

D: Manifold Absolute Pressure (MAP) Sensor
  D: Introduction  

 

D1 DIAGNOSTIC TROUBLE CODE (DTC) P0236, P1247 AND P1248

Are manifolds and MAP hose OK and free of damage?
YesNo
GO to D2.REPAIR leak as necessary. CLEAR DTCs and RETEST.
 

D2 MAP FREQUENCY CHECK

Is frequency reading between 90 hz and 115 hz?
YesNo
GO to D3.REPLACE MAP sensor. CLEAR DTCs and RETEST.
 

D3 MAP SENSOR PRESSURE CHECK

Is frequency reading 145 hz ± 10 hz?
YesNo
GO to D4.REPLACE MAP sensor. CLEAR DTCs and RETEST.
 

D4 MAP PERFORMANCE TEST

Is engine boost 82 kPa (12 psi) or greater?
YesNo
CLEAR DTCs and RETEST. If DTC returns, REPLACE ECM.INSPECT intake manifolds, crossover tubes for leaks. CHECK turbo condition. REFER to the Powertrain/Engine Group in the Service Manual.
 

D5 KOEO DIAGNOSTIC TROUBLE CODE (DTC) P0237

Is green light on?
YesNo
GO to D6.Red light "less than 4V" on or no lights, GO to D11. Red light "greater than 6V" on, GO to D14.
 

D6 MAP SIGNAL SHORT TO GROUND CHECK

Is each resistance greater than 10,000 ohms?
YesNo
GO to D7.REPAIR short to ground or signal return in MAP signal Circuit 358 (LG/BK). CLEAR DTCs and RETEST.
 

D7 MAP SIGNAL SHORT TO VOLTAGE CHECK

Is each resistance greater than 10,000 ohms?
YesNo
GO to D8.REPAIR short to power in MAP signal Circuit 358 (LG/BK) and REPLACE MAP sensor. CLEAR DTCs and RETEST.
 

D8 MAP SIGNAL SHORT TO VREF CHECK

Is resistance greater than 10,000 ohms?
YesNo
GO to D9.REPAIR short to VREF in MAP signal Circuit 358 (LG/BK). CLEAR DTCs and RETEST.
 

D9 MAP SIGNAL CONTINUITY CHECK

Is resistance less than 5 ohms?
YesNo
GO to D10.REPAIR open MAP signal Circuit 358 (LG/BK). CLEAR DTCs and RETEST.
 

D10 PCM CHECK

Is voltage reading 5 volts ± 0.5v?
YesNo
REPLACE MAP sensor. CLEAR DTCs and RETEST.REPLACE PCM. CLEAR DTCs and RETEST.
 

D11 VREF VOLTAGE CHECK

Is green light on tester now on?
YesNo
REPLACE MAP sensor. CLEAR DTCs and RETEST.GO to D12.
 

D12 VREF CONTINUITY CHECK

Is resistance less than 5 ohms?
YesNo
GO to D13.REPAIR open in VREF Circuit 351 (BR/W) between PCM and MAP sensor.
 

D13 SIGNAL RETURN CONTINUITY CHECK

Is resistance less than 5 ohms?
YesNo
REPLACE PCM. CLEAR DTCs and RETEST.REPAIR open in signal return Circuit 359 (GY/R).
 

D14 VREF SHORT TO B+ CHECK

Is voltage reading less than 0.25v?
YesNo
REPLACE PCM. CLEAR DTCs and RETEST.REPAIR short to B+ in VREF circuit. CLEAR DTCs and RETEST.
 

D15 KOEO DIAGNOSTIC TROUBLE CODE (DTC) P0238

Is frequency reading above 125 hz?
YesNo
REPLACE MAP sensor. CLEAR DTCs and RETEST.REPLACE PCM. CLEAR DTCs and RETEST.
 

D16 CONTINUOUS DIAGNOSTIC TROUBLE CODE (DTC) P0237 OR P0235

Is frequency reading 110 hz ± 5 hz?
YesNo
GO to D17.REPLACE MAP sensor.
 

D17 MAP SENSOR CHECK

Does reading fluctuate?
YesNo
REPLACE MAP sensor. CLEAR DTCs and RETEST.GO to D18.
 

D18 MAP SENSOR PSI CHECK

Does reading fluctuate?
YesNo
REPLACE MAP sensor. CLEAR DTCs and RETEST.GO to D19.
 

D19 SIGNAL RETURN HARNESS CHECK

Does resistance reading fluctuate?
YesNo
REPAIR intermittent open in Circuit 359 (GY/R) as required. CLEAR DTCs and RETEST.GO to D20.
 

D20 VREF CIRCUIT CHECK

Does voltage value fluctuate?
YesNo
REPAIR intermittent open in Circuit 351 (BR/W) as required. CLEAR DTCs and RETEST.GO to D21.
 

D21 MAP SIGNAL WIRE CONTINUITY CHECK

Does resistance stay below 5 ohms?
YesNo
GO to D22.REPAIR intermittent open in Circuit 358 (LG/BK). CLEAR DTCs and RETEST.
 

D22 MAP SIGNAL WIRE SHORT TO GND

Does resistance value drop below 10,000 ohms?
YesNo
REPAIR intermittent short to ground in Circuit 358 (LG/BK). CLEAR DTCs and RETEST.GO to D23.
 

D23 MAP SIGNAL WIRE SHORT TO PWR

Does voltage reading go above 0v?
YesNo
REPAIR intermittent short to PWR in circuit 358 (LG/BK). CLEAR DTCs and RETEST.Intermittent failure. Unable to VERIFY. CLEAR DTCs.
 

D24 CONTINUOUS DIAGNOSTIC TROUBLE CODE (DTC) P0238

Does frequency reading go above 125 hz?
YesNo
REPLACE MAP sensor. CLEAR DTCs and RETEST.GO to D25.
 

D25 CHECK MAP SENSOR

Does frequency reading go above 300 hz?
YesNo
REPLACE MAP sensor. CLEAR DTCs and RETEST.GO to D26.
 

D26 MAP HARNESS CHECK

Does frequency reading go above 300 hz?
YesNo
REPAIR intermittent circuit failure. CLEAR DTCs and RETEST.FAILURE is intermittent. Unable to duplicate at this time. CLEAR DTCs.