1996 PCED OBDI | SECTION 18: Diesel Diagnosis — 7.3L DI Engine |
AC1 DIAGNOSTIC TROUBLE CODE (DTC) 0107: BARO CIRCUIT LOW INPUT
- DTC 0107 indicates barometric pressure out of range low was detected during KOEO Self Test or during continuous diagnostic monitoring.
- Possible causes:
- Open BARO sensor circuit
- Biased BARO sensor/PCM
- Short to SIG RTN or PWR GND on BARO sensor circuit
- Open VREF circuit
- Key off.
- Disconnect BARO sensor connector.
- Key on/engine off.
- Measure voltage from Pin 2 at harness connector to ground.
Is reading 5v±.5?
| Yes | No |
|---|
| GO to AC2. | SERVICE open in Circuit 351 (BR/W). CLEAR DTCs and RETEST. |
AC2 SIGNAL RETURN CIRCUIT CHECK
- Measure voltage from VREF Pin 2 to signal return Pin 1.
Is voltage reading 5v±.5?
| Yes | No |
|---|
| GO to AC3. | REPAIR open in signal return Circuit 359 (GY/R). CLEAR DTCs and RETEST. |
AC3 BARO SIGNAL WIRE CHECK
- Key off.
- Disconnect PCM. Inspect for damaged, pushed out, or corroded pins. Service as necessary.
- Connect breakout box. PCM disconnected.
- Measure resistance from Pin 84 to signal wire Pin 3 at sensor connector.
Is resistance less than 5 ohms?
| Yes | No |
|---|
| GO to AC4. | REPAIR open in Circuit 356 (DB/LG). CLEAR DTCs and RETEST. |
AC4 VREF CIRCUIT CHECK
- Measure resistance from Test Pin 90 to Pin 2 of BARO sensor harness connector.
Is resistance less than 5 ohms?
| Yes | No |
|---|
| GO to AC5. | REPAIR open in VREF Circuit 351 (BR/W). CLEAR DTCs and RETEST. |
AC5 SIG RTN CIRCUIT CHECK
- Measure resistance from Test Pin 91 to Pin 1 of BARO harness connector.
Is resistance less than 5 ohms?
| Yes | No |
|---|
| GO to AC6. | REPAIR open in SIG RTN Circuit 359 (GY/R). CLEAR DTCs and RETEST. |
AC6 GROUNDED SIGNAL WIRE CHECK
- Measure resistance from Pin 84 to Pins 25/51/76/77/91 and 103.
Is resistance greater than 10,000 ohms?
| Yes | No |
|---|
| GO to AC7. | REPAIR short to ground in Circuit 356 (DB/LG). CLEAR DTCs and RETEST. |
AC7 GROUNDED SIGNAL WIRE CHECK
- Connect breakout box to PCM.
- Measure resistance between Pin 84 and Pins 25/91/51/76/77 and 103.
Is resistance greater than 10,000 ohms?
| Yes | No |
|---|
| REPLACE BARO sensor. CLEAR DTCs and RETEST. | REPLACE PCM. REMOVE breakout box. CLEAR DTCs and RETEST. |
AC8 DIAGNOSTIC TROUBLE CODE (DTC) 0108: BARO CIRCUIT HIGH INPUT
- DTC 0108 indicates barometric pressure out of range high during KOEO Self Test or during continuous diagnostic monitoring.
- Possible causes:
- Biased BARO sensor/PCM
- BARO circuit shorted to VREF
- Key on.
- Attempt to induce opposite DTC.
- Disconnect BARO sensor.
- Check DTCs.
Does DTC 0107 appear?
| Yes | No |
|---|
| REPLACE BARO sensor CLEAR DTCs and RETEST. | GO to AC9. |
AC9 CHECK FOR SIGNAL WIRE POWER SHORT
- Key off.
- Disconnect PCM. Inspect for damaged, loose, corroded or pushed out pins.
- Connect breakout box. PCM disconnected.
- Measure resistance from Pin 84 to Pins 55/71/90/97.
Is resistance greater than 10,000 ohms?
| Yes | No |
|---|
| REPLACE PCM. CLEAR DTCs and RETEST. | REPAIR short to power in signal wire Circuit 356 (DB/LG). CLEAR DTCs and RETEST. |
AC: Introduction